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Carla Floricel
2022-08-02 09:52:52 -04:00
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"""
The :mod:`sklearn.metrics` module includes score functions, performance metrics
and pairwise metrics and distance computations.
"""
from ._ranking import auc
from ._ranking import average_precision_score
from ._ranking import coverage_error
from ._ranking import det_curve
from ._ranking import dcg_score
from ._ranking import label_ranking_average_precision_score
from ._ranking import label_ranking_loss
from ._ranking import ndcg_score
from ._ranking import precision_recall_curve
from ._ranking import roc_auc_score
from ._ranking import roc_curve
from ._ranking import top_k_accuracy_score
from ._classification import accuracy_score
from ._classification import balanced_accuracy_score
from ._classification import classification_report
from ._classification import cohen_kappa_score
from ._classification import confusion_matrix
from ._classification import f1_score
from ._classification import fbeta_score
from ._classification import hamming_loss
from ._classification import hinge_loss
from ._classification import jaccard_score
from ._classification import log_loss
from ._classification import matthews_corrcoef
from ._classification import precision_recall_fscore_support
from ._classification import precision_score
from ._classification import recall_score
from ._classification import zero_one_loss
from ._classification import brier_score_loss
from ._classification import multilabel_confusion_matrix
from ._dist_metrics import DistanceMetric
from . import cluster
from .cluster import adjusted_mutual_info_score
from .cluster import adjusted_rand_score
from .cluster import rand_score
from .cluster import pair_confusion_matrix
from .cluster import completeness_score
from .cluster import consensus_score
from .cluster import homogeneity_completeness_v_measure
from .cluster import homogeneity_score
from .cluster import mutual_info_score
from .cluster import normalized_mutual_info_score
from .cluster import fowlkes_mallows_score
from .cluster import silhouette_samples
from .cluster import silhouette_score
from .cluster import calinski_harabasz_score
from .cluster import v_measure_score
from .cluster import davies_bouldin_score
from .pairwise import euclidean_distances
from .pairwise import nan_euclidean_distances
from .pairwise import pairwise_distances
from .pairwise import pairwise_distances_argmin
from .pairwise import pairwise_distances_argmin_min
from .pairwise import pairwise_kernels
from .pairwise import pairwise_distances_chunked
from ._regression import explained_variance_score
from ._regression import max_error
from ._regression import mean_absolute_error
from ._regression import mean_squared_error
from ._regression import mean_squared_log_error
from ._regression import median_absolute_error
from ._regression import mean_absolute_percentage_error
from ._regression import mean_pinball_loss
from ._regression import r2_score
from ._regression import mean_tweedie_deviance
from ._regression import mean_poisson_deviance
from ._regression import mean_gamma_deviance
from ._regression import d2_tweedie_score
from ._regression import d2_pinball_score
from ._regression import d2_absolute_error_score
from ._scorer import check_scoring
from ._scorer import make_scorer
from ._scorer import SCORERS
from ._scorer import get_scorer
from ._scorer import get_scorer_names
from ._plot.det_curve import plot_det_curve
from ._plot.det_curve import DetCurveDisplay
from ._plot.roc_curve import plot_roc_curve
from ._plot.roc_curve import RocCurveDisplay
from ._plot.precision_recall_curve import plot_precision_recall_curve
from ._plot.precision_recall_curve import PrecisionRecallDisplay
from ._plot.confusion_matrix import plot_confusion_matrix
from ._plot.confusion_matrix import ConfusionMatrixDisplay
__all__ = [
"accuracy_score",
"adjusted_mutual_info_score",
"adjusted_rand_score",
"auc",
"average_precision_score",
"balanced_accuracy_score",
"calinski_harabasz_score",
"check_scoring",
"classification_report",
"cluster",
"cohen_kappa_score",
"completeness_score",
"ConfusionMatrixDisplay",
"confusion_matrix",
"consensus_score",
"coverage_error",
"d2_tweedie_score",
"d2_absolute_error_score",
"d2_pinball_score",
"dcg_score",
"davies_bouldin_score",
"DetCurveDisplay",
"det_curve",
"DistanceMetric",
"euclidean_distances",
"explained_variance_score",
"f1_score",
"fbeta_score",
"fowlkes_mallows_score",
"get_scorer",
"hamming_loss",
"hinge_loss",
"homogeneity_completeness_v_measure",
"homogeneity_score",
"jaccard_score",
"label_ranking_average_precision_score",
"label_ranking_loss",
"log_loss",
"make_scorer",
"nan_euclidean_distances",
"matthews_corrcoef",
"max_error",
"mean_absolute_error",
"mean_squared_error",
"mean_squared_log_error",
"mean_pinball_loss",
"mean_poisson_deviance",
"mean_gamma_deviance",
"mean_tweedie_deviance",
"median_absolute_error",
"mean_absolute_percentage_error",
"multilabel_confusion_matrix",
"mutual_info_score",
"ndcg_score",
"normalized_mutual_info_score",
"pair_confusion_matrix",
"pairwise_distances",
"pairwise_distances_argmin",
"pairwise_distances_argmin_min",
"pairwise_distances_chunked",
"pairwise_kernels",
"plot_confusion_matrix",
"plot_det_curve",
"plot_precision_recall_curve",
"plot_roc_curve",
"PrecisionRecallDisplay",
"precision_recall_curve",
"precision_recall_fscore_support",
"precision_score",
"r2_score",
"rand_score",
"recall_score",
"RocCurveDisplay",
"roc_auc_score",
"roc_curve",
"SCORERS",
"get_scorer_names",
"silhouette_samples",
"silhouette_score",
"top_k_accuracy_score",
"v_measure_score",
"zero_one_loss",
"brier_score_loss",
]

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"""
Common code for all metrics.
"""
# Authors: Alexandre Gramfort <alexandre.gramfort@inria.fr>
# Mathieu Blondel <mathieu@mblondel.org>
# Olivier Grisel <olivier.grisel@ensta.org>
# Arnaud Joly <a.joly@ulg.ac.be>
# Jochen Wersdorfer <jochen@wersdoerfer.de>
# Lars Buitinck
# Joel Nothman <joel.nothman@gmail.com>
# Noel Dawe <noel@dawe.me>
# License: BSD 3 clause
from itertools import combinations
import numpy as np
from ..utils import check_array, check_consistent_length
from ..utils.multiclass import type_of_target
def _average_binary_score(binary_metric, y_true, y_score, average, sample_weight=None):
"""Average a binary metric for multilabel classification.
Parameters
----------
y_true : array, shape = [n_samples] or [n_samples, n_classes]
True binary labels in binary label indicators.
y_score : array, shape = [n_samples] or [n_samples, n_classes]
Target scores, can either be probability estimates of the positive
class, confidence values, or binary decisions.
average : {None, 'micro', 'macro', 'samples', 'weighted'}, default='macro'
If ``None``, the scores for each class are returned. Otherwise,
this determines the type of averaging performed on the data:
``'micro'``:
Calculate metrics globally by considering each element of the label
indicator matrix as a label.
``'macro'``:
Calculate metrics for each label, and find their unweighted
mean. This does not take label imbalance into account.
``'weighted'``:
Calculate metrics for each label, and find their average, weighted
by support (the number of true instances for each label).
``'samples'``:
Calculate metrics for each instance, and find their average.
Will be ignored when ``y_true`` is binary.
sample_weight : array-like of shape (n_samples,), default=None
Sample weights.
binary_metric : callable, returns shape [n_classes]
The binary metric function to use.
Returns
-------
score : float or array of shape [n_classes]
If not ``None``, average the score, else return the score for each
classes.
"""
average_options = (None, "micro", "macro", "weighted", "samples")
if average not in average_options:
raise ValueError("average has to be one of {0}".format(average_options))
y_type = type_of_target(y_true)
if y_type not in ("binary", "multilabel-indicator"):
raise ValueError("{0} format is not supported".format(y_type))
if y_type == "binary":
return binary_metric(y_true, y_score, sample_weight=sample_weight)
check_consistent_length(y_true, y_score, sample_weight)
y_true = check_array(y_true)
y_score = check_array(y_score)
not_average_axis = 1
score_weight = sample_weight
average_weight = None
if average == "micro":
if score_weight is not None:
score_weight = np.repeat(score_weight, y_true.shape[1])
y_true = y_true.ravel()
y_score = y_score.ravel()
elif average == "weighted":
if score_weight is not None:
average_weight = np.sum(
np.multiply(y_true, np.reshape(score_weight, (-1, 1))), axis=0
)
else:
average_weight = np.sum(y_true, axis=0)
if np.isclose(average_weight.sum(), 0.0):
return 0
elif average == "samples":
# swap average_weight <-> score_weight
average_weight = score_weight
score_weight = None
not_average_axis = 0
if y_true.ndim == 1:
y_true = y_true.reshape((-1, 1))
if y_score.ndim == 1:
y_score = y_score.reshape((-1, 1))
n_classes = y_score.shape[not_average_axis]
score = np.zeros((n_classes,))
for c in range(n_classes):
y_true_c = y_true.take([c], axis=not_average_axis).ravel()
y_score_c = y_score.take([c], axis=not_average_axis).ravel()
score[c] = binary_metric(y_true_c, y_score_c, sample_weight=score_weight)
# Average the results
if average is not None:
if average_weight is not None:
# Scores with 0 weights are forced to be 0, preventing the average
# score from being affected by 0-weighted NaN elements.
average_weight = np.asarray(average_weight)
score[average_weight == 0] = 0
return np.average(score, weights=average_weight)
else:
return score
def _average_multiclass_ovo_score(binary_metric, y_true, y_score, average="macro"):
"""Average one-versus-one scores for multiclass classification.
Uses the binary metric for one-vs-one multiclass classification,
where the score is computed according to the Hand & Till (2001) algorithm.
Parameters
----------
binary_metric : callable
The binary metric function to use that accepts the following as input:
y_true_target : array, shape = [n_samples_target]
Some sub-array of y_true for a pair of classes designated
positive and negative in the one-vs-one scheme.
y_score_target : array, shape = [n_samples_target]
Scores corresponding to the probability estimates
of a sample belonging to the designated positive class label
y_true : array-like of shape (n_samples,)
True multiclass labels.
y_score : array-like of shape (n_samples, n_classes)
Target scores corresponding to probability estimates of a sample
belonging to a particular class.
average : {'macro', 'weighted'}, default='macro'
Determines the type of averaging performed on the pairwise binary
metric scores:
``'macro'``:
Calculate metrics for each label, and find their unweighted
mean. This does not take label imbalance into account. Classes
are assumed to be uniformly distributed.
``'weighted'``:
Calculate metrics for each label, taking into account the
prevalence of the classes.
Returns
-------
score : float
Average of the pairwise binary metric scores.
"""
check_consistent_length(y_true, y_score)
y_true_unique = np.unique(y_true)
n_classes = y_true_unique.shape[0]
n_pairs = n_classes * (n_classes - 1) // 2
pair_scores = np.empty(n_pairs)
is_weighted = average == "weighted"
prevalence = np.empty(n_pairs) if is_weighted else None
# Compute scores treating a as positive class and b as negative class,
# then b as positive class and a as negative class
for ix, (a, b) in enumerate(combinations(y_true_unique, 2)):
a_mask = y_true == a
b_mask = y_true == b
ab_mask = np.logical_or(a_mask, b_mask)
if is_weighted:
prevalence[ix] = np.average(ab_mask)
a_true = a_mask[ab_mask]
b_true = b_mask[ab_mask]
a_true_score = binary_metric(a_true, y_score[ab_mask, a])
b_true_score = binary_metric(b_true, y_score[ab_mask, b])
pair_scores[ix] = (a_true_score + b_true_score) / 2
return np.average(pair_scores, weights=prevalence)
def _check_pos_label_consistency(pos_label, y_true):
"""Check if `pos_label` need to be specified or not.
In binary classification, we fix `pos_label=1` if the labels are in the set
{-1, 1} or {0, 1}. Otherwise, we raise an error asking to specify the
`pos_label` parameters.
Parameters
----------
pos_label : int, str or None
The positive label.
y_true : ndarray of shape (n_samples,)
The target vector.
Returns
-------
pos_label : int
If `pos_label` can be inferred, it will be returned.
Raises
------
ValueError
In the case that `y_true` does not have label in {-1, 1} or {0, 1},
it will raise a `ValueError`.
"""
# ensure binary classification if pos_label is not specified
# classes.dtype.kind in ('O', 'U', 'S') is required to avoid
# triggering a FutureWarning by calling np.array_equal(a, b)
# when elements in the two arrays are not comparable.
classes = np.unique(y_true)
if pos_label is None and (
classes.dtype.kind in "OUS"
or not (
np.array_equal(classes, [0, 1])
or np.array_equal(classes, [-1, 1])
or np.array_equal(classes, [0])
or np.array_equal(classes, [-1])
or np.array_equal(classes, [1])
)
):
classes_repr = ", ".join(repr(c) for c in classes)
raise ValueError(
f"y_true takes value in {{{classes_repr}}} and pos_label is not "
"specified: either make y_true take value in {0, 1} or "
"{-1, 1} or pass pos_label explicitly."
)
elif pos_label is None:
pos_label = 1
return pos_label

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cimport numpy as np
from libc.math cimport sqrt, exp
from ..utils._typedefs cimport DTYPE_t, ITYPE_t
######################################################################
# Inline distance functions
#
# We use these for the default (euclidean) case so that they can be
# inlined. This leads to faster computation for the most common case
cdef inline DTYPE_t euclidean_dist(const DTYPE_t* x1, const DTYPE_t* x2,
ITYPE_t size) nogil except -1:
cdef DTYPE_t tmp, d=0
cdef np.intp_t j
for j in range(size):
tmp = x1[j] - x2[j]
d += tmp * tmp
return sqrt(d)
cdef inline DTYPE_t euclidean_rdist(const DTYPE_t* x1, const DTYPE_t* x2,
ITYPE_t size) nogil except -1:
cdef DTYPE_t tmp, d=0
cdef np.intp_t j
for j in range(size):
tmp = x1[j] - x2[j]
d += tmp * tmp
return d
cdef inline DTYPE_t euclidean_dist_to_rdist(const DTYPE_t dist) nogil except -1:
return dist * dist
cdef inline DTYPE_t euclidean_rdist_to_dist(const DTYPE_t dist) nogil except -1:
return sqrt(dist)
######################################################################
# DistanceMetric base class
cdef class DistanceMetric:
# The following attributes are required for a few of the subclasses.
# we must define them here so that cython's limited polymorphism will work.
# Because we don't expect to instantiate a lot of these objects, the
# extra memory overhead of this setup should not be an issue.
cdef DTYPE_t p
cdef DTYPE_t[::1] vec
cdef DTYPE_t[:, ::1] mat
cdef ITYPE_t size
cdef object func
cdef object kwargs
cdef DTYPE_t dist(self, const DTYPE_t* x1, const DTYPE_t* x2,
ITYPE_t size) nogil except -1
cdef DTYPE_t rdist(self, const DTYPE_t* x1, const DTYPE_t* x2,
ITYPE_t size) nogil except -1
cdef int pdist(self, const DTYPE_t[:, ::1] X, DTYPE_t[:, ::1] D) except -1
cdef int cdist(self, const DTYPE_t[:, ::1] X, const DTYPE_t[:, ::1] Y,
DTYPE_t[:, ::1] D) except -1
cdef DTYPE_t _rdist_to_dist(self, DTYPE_t rdist) nogil except -1
cdef DTYPE_t _dist_to_rdist(self, DTYPE_t dist) nogil except -1
######################################################################
# DatasetsPair base class
cdef class DatasetsPair:
cdef DistanceMetric distance_metric
cdef ITYPE_t n_samples_X(self) nogil
cdef ITYPE_t n_samples_Y(self) nogil
cdef DTYPE_t dist(self, ITYPE_t i, ITYPE_t j) nogil
cdef DTYPE_t surrogate_dist(self, ITYPE_t i, ITYPE_t j) nogil
cdef class DenseDenseDatasetsPair(DatasetsPair):
cdef:
const DTYPE_t[:, ::1] X
const DTYPE_t[:, ::1] Y
ITYPE_t d

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from ...base import is_classifier
def _check_classifier_response_method(estimator, response_method):
"""Return prediction method from the response_method
Parameters
----------
estimator: object
Classifier to check
response_method: {'auto', 'predict_proba', 'decision_function'}
Specifies whether to use :term:`predict_proba` or
:term:`decision_function` as the target response. If set to 'auto',
:term:`predict_proba` is tried first and if it does not exist
:term:`decision_function` is tried next.
Returns
-------
prediction_method: callable
prediction method of estimator
"""
if response_method not in ("predict_proba", "decision_function", "auto"):
raise ValueError(
"response_method must be 'predict_proba', 'decision_function' or 'auto'"
)
error_msg = "response method {} is not defined in {}"
if response_method != "auto":
prediction_method = getattr(estimator, response_method, None)
if prediction_method is None:
raise ValueError(
error_msg.format(response_method, estimator.__class__.__name__)
)
else:
predict_proba = getattr(estimator, "predict_proba", None)
decision_function = getattr(estimator, "decision_function", None)
prediction_method = predict_proba or decision_function
if prediction_method is None:
raise ValueError(
error_msg.format(
"decision_function or predict_proba", estimator.__class__.__name__
)
)
return prediction_method
def _get_response(X, estimator, response_method, pos_label=None):
"""Return response and positive label.
Parameters
----------
X : {array-like, sparse matrix} of shape (n_samples, n_features)
Input values.
estimator : estimator instance
Fitted classifier or a fitted :class:`~sklearn.pipeline.Pipeline`
in which the last estimator is a classifier.
response_method: {'auto', 'predict_proba', 'decision_function'}
Specifies whether to use :term:`predict_proba` or
:term:`decision_function` as the target response. If set to 'auto',
:term:`predict_proba` is tried first and if it does not exist
:term:`decision_function` is tried next.
pos_label : str or int, default=None
The class considered as the positive class when computing
the metrics. By default, `estimators.classes_[1]` is
considered as the positive class.
Returns
-------
y_pred: ndarray of shape (n_samples,)
Target scores calculated from the provided response_method
and pos_label.
pos_label: str or int
The class considered as the positive class when computing
the metrics.
"""
classification_error = (
"Expected 'estimator' to be a binary classifier, but got"
f" {estimator.__class__.__name__}"
)
if not is_classifier(estimator):
raise ValueError(classification_error)
prediction_method = _check_classifier_response_method(estimator, response_method)
y_pred = prediction_method(X)
if pos_label is not None:
try:
class_idx = estimator.classes_.tolist().index(pos_label)
except ValueError as e:
raise ValueError(
"The class provided by 'pos_label' is unknown. Got "
f"{pos_label} instead of one of {set(estimator.classes_)}"
) from e
else:
class_idx = 1
pos_label = estimator.classes_[class_idx]
if y_pred.ndim != 1: # `predict_proba`
y_pred_shape = y_pred.shape[1]
if y_pred_shape != 2:
raise ValueError(
f"{classification_error} fit on multiclass ({y_pred_shape} classes)"
" data"
)
y_pred = y_pred[:, class_idx]
elif pos_label == estimator.classes_[0]: # `decision_function`
y_pred *= -1
return y_pred, pos_label

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from itertools import product
import numpy as np
from .. import confusion_matrix
from ...utils import check_matplotlib_support
from ...utils import deprecated
from ...utils.multiclass import unique_labels
from ...base import is_classifier
class ConfusionMatrixDisplay:
"""Confusion Matrix visualization.
It is recommend to use
:func:`~sklearn.metrics.ConfusionMatrixDisplay.from_estimator` or
:func:`~sklearn.metrics.ConfusionMatrixDisplay.from_predictions` to
create a :class:`ConfusionMatrixDisplay`. All parameters are stored as
attributes.
Read more in the :ref:`User Guide <visualizations>`.
Parameters
----------
confusion_matrix : ndarray of shape (n_classes, n_classes)
Confusion matrix.
display_labels : ndarray of shape (n_classes,), default=None
Display labels for plot. If None, display labels are set from 0 to
`n_classes - 1`.
Attributes
----------
im_ : matplotlib AxesImage
Image representing the confusion matrix.
text_ : ndarray of shape (n_classes, n_classes), dtype=matplotlib Text, \
or None
Array of matplotlib axes. `None` if `include_values` is false.
ax_ : matplotlib Axes
Axes with confusion matrix.
figure_ : matplotlib Figure
Figure containing the confusion matrix.
See Also
--------
confusion_matrix : Compute Confusion Matrix to evaluate the accuracy of a
classification.
ConfusionMatrixDisplay.from_estimator : Plot the confusion matrix
given an estimator, the data, and the label.
ConfusionMatrixDisplay.from_predictions : Plot the confusion matrix
given the true and predicted labels.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> from sklearn.datasets import make_classification
>>> from sklearn.metrics import confusion_matrix, ConfusionMatrixDisplay
>>> from sklearn.model_selection import train_test_split
>>> from sklearn.svm import SVC
>>> X, y = make_classification(random_state=0)
>>> X_train, X_test, y_train, y_test = train_test_split(X, y,
... random_state=0)
>>> clf = SVC(random_state=0)
>>> clf.fit(X_train, y_train)
SVC(random_state=0)
>>> predictions = clf.predict(X_test)
>>> cm = confusion_matrix(y_test, predictions, labels=clf.classes_)
>>> disp = ConfusionMatrixDisplay(confusion_matrix=cm,
... display_labels=clf.classes_)
>>> disp.plot()
<...>
>>> plt.show()
"""
def __init__(self, confusion_matrix, *, display_labels=None):
self.confusion_matrix = confusion_matrix
self.display_labels = display_labels
def plot(
self,
*,
include_values=True,
cmap="viridis",
xticks_rotation="horizontal",
values_format=None,
ax=None,
colorbar=True,
im_kw=None,
):
"""Plot visualization.
Parameters
----------
include_values : bool, default=True
Includes values in confusion matrix.
cmap : str or matplotlib Colormap, default='viridis'
Colormap recognized by matplotlib.
xticks_rotation : {'vertical', 'horizontal'} or float, \
default='horizontal'
Rotation of xtick labels.
values_format : str, default=None
Format specification for values in confusion matrix. If `None`,
the format specification is 'd' or '.2g' whichever is shorter.
ax : matplotlib axes, default=None
Axes object to plot on. If `None`, a new figure and axes is
created.
colorbar : bool, default=True
Whether or not to add a colorbar to the plot.
im_kw : dict, default=None
Dict with keywords passed to `matplotlib.pyplot.imshow` call.
Returns
-------
display : :class:`~sklearn.metrics.ConfusionMatrixDisplay`
"""
check_matplotlib_support("ConfusionMatrixDisplay.plot")
import matplotlib.pyplot as plt
if ax is None:
fig, ax = plt.subplots()
else:
fig = ax.figure
cm = self.confusion_matrix
n_classes = cm.shape[0]
default_im_kw = dict(interpolation="nearest", cmap=cmap)
im_kw = im_kw or {}
im_kw = {**default_im_kw, **im_kw}
self.im_ = ax.imshow(cm, **im_kw)
self.text_ = None
cmap_min, cmap_max = self.im_.cmap(0), self.im_.cmap(1.0)
if include_values:
self.text_ = np.empty_like(cm, dtype=object)
# print text with appropriate color depending on background
thresh = (cm.max() + cm.min()) / 2.0
for i, j in product(range(n_classes), range(n_classes)):
color = cmap_max if cm[i, j] < thresh else cmap_min
if values_format is None:
text_cm = format(cm[i, j], ".2g")
if cm.dtype.kind != "f":
text_d = format(cm[i, j], "d")
if len(text_d) < len(text_cm):
text_cm = text_d
else:
text_cm = format(cm[i, j], values_format)
self.text_[i, j] = ax.text(
j, i, text_cm, ha="center", va="center", color=color
)
if self.display_labels is None:
display_labels = np.arange(n_classes)
else:
display_labels = self.display_labels
if colorbar:
fig.colorbar(self.im_, ax=ax)
ax.set(
xticks=np.arange(n_classes),
yticks=np.arange(n_classes),
xticklabels=display_labels,
yticklabels=display_labels,
ylabel="True label",
xlabel="Predicted label",
)
ax.set_ylim((n_classes - 0.5, -0.5))
plt.setp(ax.get_xticklabels(), rotation=xticks_rotation)
self.figure_ = fig
self.ax_ = ax
return self
@classmethod
def from_estimator(
cls,
estimator,
X,
y,
*,
labels=None,
sample_weight=None,
normalize=None,
display_labels=None,
include_values=True,
xticks_rotation="horizontal",
values_format=None,
cmap="viridis",
ax=None,
colorbar=True,
im_kw=None,
):
"""Plot Confusion Matrix given an estimator and some data.
Read more in the :ref:`User Guide <confusion_matrix>`.
.. versionadded:: 1.0
Parameters
----------
estimator : estimator instance
Fitted classifier or a fitted :class:`~sklearn.pipeline.Pipeline`
in which the last estimator is a classifier.
X : {array-like, sparse matrix} of shape (n_samples, n_features)
Input values.
y : array-like of shape (n_samples,)
Target values.
labels : array-like of shape (n_classes,), default=None
List of labels to index the confusion matrix. This may be used to
reorder or select a subset of labels. If `None` is given, those
that appear at least once in `y_true` or `y_pred` are used in
sorted order.
sample_weight : array-like of shape (n_samples,), default=None
Sample weights.
normalize : {'true', 'pred', 'all'}, default=None
Either to normalize the counts display in the matrix:
- if `'true'`, the confusion matrix is normalized over the true
conditions (e.g. rows);
- if `'pred'`, the confusion matrix is normalized over the
predicted conditions (e.g. columns);
- if `'all'`, the confusion matrix is normalized by the total
number of samples;
- if `None` (default), the confusion matrix will not be normalized.
display_labels : array-like of shape (n_classes,), default=None
Target names used for plotting. By default, `labels` will be used
if it is defined, otherwise the unique labels of `y_true` and
`y_pred` will be used.
include_values : bool, default=True
Includes values in confusion matrix.
xticks_rotation : {'vertical', 'horizontal'} or float, \
default='horizontal'
Rotation of xtick labels.
values_format : str, default=None
Format specification for values in confusion matrix. If `None`, the
format specification is 'd' or '.2g' whichever is shorter.
cmap : str or matplotlib Colormap, default='viridis'
Colormap recognized by matplotlib.
ax : matplotlib Axes, default=None
Axes object to plot on. If `None`, a new figure and axes is
created.
colorbar : bool, default=True
Whether or not to add a colorbar to the plot.
im_kw : dict, default=None
Dict with keywords passed to `matplotlib.pyplot.imshow` call.
Returns
-------
display : :class:`~sklearn.metrics.ConfusionMatrixDisplay`
See Also
--------
ConfusionMatrixDisplay.from_predictions : Plot the confusion matrix
given the true and predicted labels.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> from sklearn.datasets import make_classification
>>> from sklearn.metrics import ConfusionMatrixDisplay
>>> from sklearn.model_selection import train_test_split
>>> from sklearn.svm import SVC
>>> X, y = make_classification(random_state=0)
>>> X_train, X_test, y_train, y_test = train_test_split(
... X, y, random_state=0)
>>> clf = SVC(random_state=0)
>>> clf.fit(X_train, y_train)
SVC(random_state=0)
>>> ConfusionMatrixDisplay.from_estimator(
... clf, X_test, y_test)
<...>
>>> plt.show()
"""
method_name = f"{cls.__name__}.from_estimator"
check_matplotlib_support(method_name)
if not is_classifier(estimator):
raise ValueError(f"{method_name} only supports classifiers")
y_pred = estimator.predict(X)
return cls.from_predictions(
y,
y_pred,
sample_weight=sample_weight,
labels=labels,
normalize=normalize,
display_labels=display_labels,
include_values=include_values,
cmap=cmap,
ax=ax,
xticks_rotation=xticks_rotation,
values_format=values_format,
colorbar=colorbar,
im_kw=im_kw,
)
@classmethod
def from_predictions(
cls,
y_true,
y_pred,
*,
labels=None,
sample_weight=None,
normalize=None,
display_labels=None,
include_values=True,
xticks_rotation="horizontal",
values_format=None,
cmap="viridis",
ax=None,
colorbar=True,
im_kw=None,
):
"""Plot Confusion Matrix given true and predicted labels.
Read more in the :ref:`User Guide <confusion_matrix>`.
.. versionadded:: 1.0
Parameters
----------
y_true : array-like of shape (n_samples,)
True labels.
y_pred : array-like of shape (n_samples,)
The predicted labels given by the method `predict` of an
classifier.
labels : array-like of shape (n_classes,), default=None
List of labels to index the confusion matrix. This may be used to
reorder or select a subset of labels. If `None` is given, those
that appear at least once in `y_true` or `y_pred` are used in
sorted order.
sample_weight : array-like of shape (n_samples,), default=None
Sample weights.
normalize : {'true', 'pred', 'all'}, default=None
Either to normalize the counts display in the matrix:
- if `'true'`, the confusion matrix is normalized over the true
conditions (e.g. rows);
- if `'pred'`, the confusion matrix is normalized over the
predicted conditions (e.g. columns);
- if `'all'`, the confusion matrix is normalized by the total
number of samples;
- if `None` (default), the confusion matrix will not be normalized.
display_labels : array-like of shape (n_classes,), default=None
Target names used for plotting. By default, `labels` will be used
if it is defined, otherwise the unique labels of `y_true` and
`y_pred` will be used.
include_values : bool, default=True
Includes values in confusion matrix.
xticks_rotation : {'vertical', 'horizontal'} or float, \
default='horizontal'
Rotation of xtick labels.
values_format : str, default=None
Format specification for values in confusion matrix. If `None`, the
format specification is 'd' or '.2g' whichever is shorter.
cmap : str or matplotlib Colormap, default='viridis'
Colormap recognized by matplotlib.
ax : matplotlib Axes, default=None
Axes object to plot on. If `None`, a new figure and axes is
created.
colorbar : bool, default=True
Whether or not to add a colorbar to the plot.
im_kw : dict, default=None
Dict with keywords passed to `matplotlib.pyplot.imshow` call.
Returns
-------
display : :class:`~sklearn.metrics.ConfusionMatrixDisplay`
See Also
--------
ConfusionMatrixDisplay.from_estimator : Plot the confusion matrix
given an estimator, the data, and the label.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> from sklearn.datasets import make_classification
>>> from sklearn.metrics import ConfusionMatrixDisplay
>>> from sklearn.model_selection import train_test_split
>>> from sklearn.svm import SVC
>>> X, y = make_classification(random_state=0)
>>> X_train, X_test, y_train, y_test = train_test_split(
... X, y, random_state=0)
>>> clf = SVC(random_state=0)
>>> clf.fit(X_train, y_train)
SVC(random_state=0)
>>> y_pred = clf.predict(X_test)
>>> ConfusionMatrixDisplay.from_predictions(
... y_test, y_pred)
<...>
>>> plt.show()
"""
check_matplotlib_support(f"{cls.__name__}.from_predictions")
if display_labels is None:
if labels is None:
display_labels = unique_labels(y_true, y_pred)
else:
display_labels = labels
cm = confusion_matrix(
y_true,
y_pred,
sample_weight=sample_weight,
labels=labels,
normalize=normalize,
)
disp = cls(confusion_matrix=cm, display_labels=display_labels)
return disp.plot(
include_values=include_values,
cmap=cmap,
ax=ax,
xticks_rotation=xticks_rotation,
values_format=values_format,
colorbar=colorbar,
im_kw=im_kw,
)
@deprecated(
"Function `plot_confusion_matrix` is deprecated in 1.0 and will be "
"removed in 1.2. Use one of the class methods: "
"ConfusionMatrixDisplay.from_predictions or "
"ConfusionMatrixDisplay.from_estimator."
)
def plot_confusion_matrix(
estimator,
X,
y_true,
*,
labels=None,
sample_weight=None,
normalize=None,
display_labels=None,
include_values=True,
xticks_rotation="horizontal",
values_format=None,
cmap="viridis",
ax=None,
colorbar=True,
):
"""Plot Confusion Matrix.
`plot_confusion_matrix` is deprecated in 1.0 and will be removed in
1.2. Use one of the following class methods:
:func:`~sklearn.metrics.ConfusionMatrixDisplay.from_predictions` or
:func:`~sklearn.metrics.ConfusionMatrixDisplay.from_estimator`.
Read more in the :ref:`User Guide <confusion_matrix>`.
Parameters
----------
estimator : estimator instance
Fitted classifier or a fitted :class:`~sklearn.pipeline.Pipeline`
in which the last estimator is a classifier.
X : {array-like, sparse matrix} of shape (n_samples, n_features)
Input values.
y_true : array-like of shape (n_samples,)
Target values.
labels : array-like of shape (n_classes,), default=None
List of labels to index the matrix. This may be used to reorder or
select a subset of labels. If `None` is given, those that appear at
least once in `y_true` or `y_pred` are used in sorted order.
sample_weight : array-like of shape (n_samples,), default=None
Sample weights.
normalize : {'true', 'pred', 'all'}, default=None
Either to normalize the counts display in the matrix:
- if `'true'`, the confusion matrix is normalized over the true
conditions (e.g. rows);
- if `'pred'`, the confusion matrix is normalized over the
predicted conditions (e.g. columns);
- if `'all'`, the confusion matrix is normalized by the total
number of samples;
- if `None` (default), the confusion matrix will not be normalized.
display_labels : array-like of shape (n_classes,), default=None
Target names used for plotting. By default, `labels` will be used if
it is defined, otherwise the unique labels of `y_true` and `y_pred`
will be used.
include_values : bool, default=True
Includes values in confusion matrix.
xticks_rotation : {'vertical', 'horizontal'} or float, \
default='horizontal'
Rotation of xtick labels.
values_format : str, default=None
Format specification for values in confusion matrix. If `None`,
the format specification is 'd' or '.2g' whichever is shorter.
cmap : str or matplotlib Colormap, default='viridis'
Colormap recognized by matplotlib.
ax : matplotlib Axes, default=None
Axes object to plot on. If `None`, a new figure and axes is
created.
colorbar : bool, default=True
Whether or not to add a colorbar to the plot.
.. versionadded:: 0.24
Returns
-------
display : :class:`~sklearn.metrics.ConfusionMatrixDisplay`
Object that stores computed values.
See Also
--------
confusion_matrix : Compute Confusion Matrix to evaluate the accuracy of a
classification.
ConfusionMatrixDisplay : Confusion Matrix visualization.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> from sklearn.datasets import make_classification
>>> from sklearn.metrics import plot_confusion_matrix
>>> from sklearn.model_selection import train_test_split
>>> from sklearn.svm import SVC
>>> X, y = make_classification(random_state=0)
>>> X_train, X_test, y_train, y_test = train_test_split(
... X, y, random_state=0)
>>> clf = SVC(random_state=0)
>>> clf.fit(X_train, y_train)
SVC(random_state=0)
>>> plot_confusion_matrix(clf, X_test, y_test) # doctest: +SKIP
>>> plt.show()
"""
check_matplotlib_support("plot_confusion_matrix")
if not is_classifier(estimator):
raise ValueError("plot_confusion_matrix only supports classifiers")
y_pred = estimator.predict(X)
cm = confusion_matrix(
y_true, y_pred, sample_weight=sample_weight, labels=labels, normalize=normalize
)
if display_labels is None:
if labels is None:
display_labels = unique_labels(y_true, y_pred)
else:
display_labels = labels
disp = ConfusionMatrixDisplay(confusion_matrix=cm, display_labels=display_labels)
return disp.plot(
include_values=include_values,
cmap=cmap,
ax=ax,
xticks_rotation=xticks_rotation,
values_format=values_format,
colorbar=colorbar,
)

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@@ -0,0 +1,472 @@
import scipy as sp
from .base import _get_response
from .. import det_curve
from .._base import _check_pos_label_consistency
from ...utils import check_matplotlib_support
from ...utils import deprecated
class DetCurveDisplay:
"""DET curve visualization.
It is recommend to use :func:`~sklearn.metrics.DetCurveDisplay.from_estimator`
or :func:`~sklearn.metrics.DetCurveDisplay.from_predictions` to create a
visualizer. All parameters are stored as attributes.
Read more in the :ref:`User Guide <visualizations>`.
.. versionadded:: 0.24
Parameters
----------
fpr : ndarray
False positive rate.
fnr : ndarray
False negative rate.
estimator_name : str, default=None
Name of estimator. If None, the estimator name is not shown.
pos_label : str or int, default=None
The label of the positive class.
Attributes
----------
line_ : matplotlib Artist
DET Curve.
ax_ : matplotlib Axes
Axes with DET Curve.
figure_ : matplotlib Figure
Figure containing the curve.
See Also
--------
det_curve : Compute error rates for different probability thresholds.
DetCurveDisplay.from_estimator : Plot DET curve given an estimator and
some data.
DetCurveDisplay.from_predictions : Plot DET curve given the true and
predicted labels.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> from sklearn.datasets import make_classification
>>> from sklearn.metrics import det_curve, DetCurveDisplay
>>> from sklearn.model_selection import train_test_split
>>> from sklearn.svm import SVC
>>> X, y = make_classification(n_samples=1000, random_state=0)
>>> X_train, X_test, y_train, y_test = train_test_split(
... X, y, test_size=0.4, random_state=0)
>>> clf = SVC(random_state=0).fit(X_train, y_train)
>>> y_pred = clf.decision_function(X_test)
>>> fpr, fnr, _ = det_curve(y_test, y_pred)
>>> display = DetCurveDisplay(
... fpr=fpr, fnr=fnr, estimator_name="SVC"
... )
>>> display.plot()
<...>
>>> plt.show()
"""
def __init__(self, *, fpr, fnr, estimator_name=None, pos_label=None):
self.fpr = fpr
self.fnr = fnr
self.estimator_name = estimator_name
self.pos_label = pos_label
@classmethod
def from_estimator(
cls,
estimator,
X,
y,
*,
sample_weight=None,
response_method="auto",
pos_label=None,
name=None,
ax=None,
**kwargs,
):
"""Plot DET curve given an estimator and data.
Read more in the :ref:`User Guide <visualizations>`.
.. versionadded:: 1.0
Parameters
----------
estimator : estimator instance
Fitted classifier or a fitted :class:`~sklearn.pipeline.Pipeline`
in which the last estimator is a classifier.
X : {array-like, sparse matrix} of shape (n_samples, n_features)
Input values.
y : array-like of shape (n_samples,)
Target values.
sample_weight : array-like of shape (n_samples,), default=None
Sample weights.
response_method : {'predict_proba', 'decision_function', 'auto'} \
default='auto'
Specifies whether to use :term:`predict_proba` or
:term:`decision_function` as the predicted target response. If set
to 'auto', :term:`predict_proba` is tried first and if it does not
exist :term:`decision_function` is tried next.
pos_label : str or int, default=None
The label of the positive class. When `pos_label=None`, if `y_true`
is in {-1, 1} or {0, 1}, `pos_label` is set to 1, otherwise an
error will be raised.
name : str, default=None
Name of DET curve for labeling. If `None`, use the name of the
estimator.
ax : matplotlib axes, default=None
Axes object to plot on. If `None`, a new figure and axes is
created.
**kwargs : dict
Additional keywords arguments passed to matplotlib `plot` function.
Returns
-------
display : :class:`~sklearn.metrics.DetCurveDisplay`
Object that stores computed values.
See Also
--------
det_curve : Compute error rates for different probability thresholds.
DetCurveDisplay.from_predictions : Plot DET curve given the true and
predicted labels.
plot_roc_curve : Plot Receiver operating characteristic (ROC) curve.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> from sklearn.datasets import make_classification
>>> from sklearn.metrics import DetCurveDisplay
>>> from sklearn.model_selection import train_test_split
>>> from sklearn.svm import SVC
>>> X, y = make_classification(n_samples=1000, random_state=0)
>>> X_train, X_test, y_train, y_test = train_test_split(
... X, y, test_size=0.4, random_state=0)
>>> clf = SVC(random_state=0).fit(X_train, y_train)
>>> DetCurveDisplay.from_estimator(
... clf, X_test, y_test)
<...>
>>> plt.show()
"""
check_matplotlib_support(f"{cls.__name__}.from_estimator")
name = estimator.__class__.__name__ if name is None else name
y_pred, pos_label = _get_response(
X,
estimator,
response_method,
pos_label=pos_label,
)
return cls.from_predictions(
y_true=y,
y_pred=y_pred,
sample_weight=sample_weight,
name=name,
ax=ax,
pos_label=pos_label,
**kwargs,
)
@classmethod
def from_predictions(
cls,
y_true,
y_pred,
*,
sample_weight=None,
pos_label=None,
name=None,
ax=None,
**kwargs,
):
"""Plot DET curve given the true and
predicted labels.
Read more in the :ref:`User Guide <visualizations>`.
.. versionadded:: 1.0
Parameters
----------
y_true : array-like of shape (n_samples,)
True labels.
y_pred : array-like of shape (n_samples,)
Target scores, can either be probability estimates of the positive
class, confidence values, or non-thresholded measure of decisions
(as returned by `decision_function` on some classifiers).
sample_weight : array-like of shape (n_samples,), default=None
Sample weights.
pos_label : str or int, default=None
The label of the positive class. When `pos_label=None`, if `y_true`
is in {-1, 1} or {0, 1}, `pos_label` is set to 1, otherwise an
error will be raised.
name : str, default=None
Name of DET curve for labeling. If `None`, name will be set to
`"Classifier"`.
ax : matplotlib axes, default=None
Axes object to plot on. If `None`, a new figure and axes is
created.
**kwargs : dict
Additional keywords arguments passed to matplotlib `plot` function.
Returns
-------
display : :class:`~sklearn.metrics.DetCurveDisplay`
Object that stores computed values.
See Also
--------
det_curve : Compute error rates for different probability thresholds.
DetCurveDisplay.from_estimator : Plot DET curve given an estimator and
some data.
plot_roc_curve : Plot Receiver operating characteristic (ROC) curve.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> from sklearn.datasets import make_classification
>>> from sklearn.metrics import DetCurveDisplay
>>> from sklearn.model_selection import train_test_split
>>> from sklearn.svm import SVC
>>> X, y = make_classification(n_samples=1000, random_state=0)
>>> X_train, X_test, y_train, y_test = train_test_split(
... X, y, test_size=0.4, random_state=0)
>>> clf = SVC(random_state=0).fit(X_train, y_train)
>>> y_pred = clf.decision_function(X_test)
>>> DetCurveDisplay.from_predictions(
... y_test, y_pred)
<...>
>>> plt.show()
"""
check_matplotlib_support(f"{cls.__name__}.from_predictions")
fpr, fnr, _ = det_curve(
y_true,
y_pred,
pos_label=pos_label,
sample_weight=sample_weight,
)
pos_label = _check_pos_label_consistency(pos_label, y_true)
name = "Classifier" if name is None else name
viz = DetCurveDisplay(
fpr=fpr,
fnr=fnr,
estimator_name=name,
pos_label=pos_label,
)
return viz.plot(ax=ax, name=name, **kwargs)
def plot(self, ax=None, *, name=None, **kwargs):
"""Plot visualization.
Parameters
----------
ax : matplotlib axes, default=None
Axes object to plot on. If `None`, a new figure and axes is
created.
name : str, default=None
Name of DET curve for labeling. If `None`, use `estimator_name` if
it is not `None`, otherwise no labeling is shown.
**kwargs : dict
Additional keywords arguments passed to matplotlib `plot` function.
Returns
-------
display : :class:`~sklearn.metrics.plot.DetCurveDisplay`
Object that stores computed values.
"""
check_matplotlib_support("DetCurveDisplay.plot")
name = self.estimator_name if name is None else name
line_kwargs = {} if name is None else {"label": name}
line_kwargs.update(**kwargs)
import matplotlib.pyplot as plt
if ax is None:
_, ax = plt.subplots()
(self.line_,) = ax.plot(
sp.stats.norm.ppf(self.fpr),
sp.stats.norm.ppf(self.fnr),
**line_kwargs,
)
info_pos_label = (
f" (Positive label: {self.pos_label})" if self.pos_label is not None else ""
)
xlabel = "False Positive Rate" + info_pos_label
ylabel = "False Negative Rate" + info_pos_label
ax.set(xlabel=xlabel, ylabel=ylabel)
if "label" in line_kwargs:
ax.legend(loc="lower right")
ticks = [0.001, 0.01, 0.05, 0.20, 0.5, 0.80, 0.95, 0.99, 0.999]
tick_locations = sp.stats.norm.ppf(ticks)
tick_labels = [
"{:.0%}".format(s) if (100 * s).is_integer() else "{:.1%}".format(s)
for s in ticks
]
ax.set_xticks(tick_locations)
ax.set_xticklabels(tick_labels)
ax.set_xlim(-3, 3)
ax.set_yticks(tick_locations)
ax.set_yticklabels(tick_labels)
ax.set_ylim(-3, 3)
self.ax_ = ax
self.figure_ = ax.figure
return self
@deprecated(
"Function plot_det_curve is deprecated in 1.0 and will be "
"removed in 1.2. Use one of the class methods: "
"DetCurveDisplay.from_predictions or "
"DetCurveDisplay.from_estimator."
)
def plot_det_curve(
estimator,
X,
y,
*,
sample_weight=None,
response_method="auto",
name=None,
ax=None,
pos_label=None,
**kwargs,
):
"""Plot detection error tradeoff (DET) curve.
Extra keyword arguments will be passed to matplotlib's `plot`.
Read more in the :ref:`User Guide <visualizations>`.
.. versionadded:: 0.24
.. deprecated:: 1.0
`plot_det_curve` is deprecated in 1.0 and will be removed in
1.2. Use one of the following class methods:
:func:`~sklearn.metrics.DetCurveDisplay.from_predictions` or
:func:`~sklearn.metrics.DetCurveDisplay.from_estimator`.
Parameters
----------
estimator : estimator instance
Fitted classifier or a fitted :class:`~sklearn.pipeline.Pipeline`
in which the last estimator is a classifier.
X : {array-like, sparse matrix} of shape (n_samples, n_features)
Input values.
y : array-like of shape (n_samples,)
Target values.
sample_weight : array-like of shape (n_samples,), default=None
Sample weights.
response_method : {'predict_proba', 'decision_function', 'auto'} \
default='auto'
Specifies whether to use :term:`predict_proba` or
:term:`decision_function` as the predicted target response. If set to
'auto', :term:`predict_proba` is tried first and if it does not exist
:term:`decision_function` is tried next.
name : str, default=None
Name of DET curve for labeling. If `None`, use the name of the
estimator.
ax : matplotlib axes, default=None
Axes object to plot on. If `None`, a new figure and axes is created.
pos_label : str or int, default=None
The label of the positive class.
When `pos_label=None`, if `y_true` is in {-1, 1} or {0, 1},
`pos_label` is set to 1, otherwise an error will be raised.
**kwargs : dict
Additional keywords arguments passed to matplotlib `plot` function.
Returns
-------
display : :class:`~sklearn.metrics.DetCurveDisplay`
Object that stores computed values.
See Also
--------
det_curve : Compute error rates for different probability thresholds.
DetCurveDisplay : DET curve visualization.
DetCurveDisplay.from_estimator : Plot DET curve given an estimator and
some data.
DetCurveDisplay.from_predictions : Plot DET curve given the true and
predicted labels.
RocCurveDisplay.from_estimator : Plot Receiver Operating Characteristic
(ROC) curve given an estimator and some data.
RocCurveDisplay.from_predictions : Plot Receiver Operating Characteristic
(ROC) curve given the true and predicted values.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> from sklearn.datasets import make_classification
>>> from sklearn.metrics import plot_det_curve
>>> from sklearn.model_selection import train_test_split
>>> from sklearn.svm import SVC
>>> X, y = make_classification(n_samples=1000, random_state=0)
>>> X_train, X_test, y_train, y_test = train_test_split(
... X, y, test_size=0.4, random_state=0)
>>> clf = SVC(random_state=0).fit(X_train, y_train)
>>> plot_det_curve(clf, X_test, y_test) # doctest: +SKIP
<...>
>>> plt.show()
"""
check_matplotlib_support("plot_det_curve")
y_pred, pos_label = _get_response(
X, estimator, response_method, pos_label=pos_label
)
fpr, fnr, _ = det_curve(
y,
y_pred,
pos_label=pos_label,
sample_weight=sample_weight,
)
name = estimator.__class__.__name__ if name is None else name
viz = DetCurveDisplay(fpr=fpr, fnr=fnr, estimator_name=name, pos_label=pos_label)
return viz.plot(ax=ax, name=name, **kwargs)

View File

@@ -0,0 +1,499 @@
from sklearn.base import is_classifier
from .base import _get_response
from .. import average_precision_score
from .. import precision_recall_curve
from .._base import _check_pos_label_consistency
from .._classification import check_consistent_length
from ...utils import check_matplotlib_support, deprecated
class PrecisionRecallDisplay:
"""Precision Recall visualization.
It is recommend to use
:func:`~sklearn.metrics.PrecisionRecallDisplay.from_estimator` or
:func:`~sklearn.metrics.PrecisionRecallDisplay.from_predictions` to create
a :class:`~sklearn.metrics.PredictionRecallDisplay`. All parameters are
stored as attributes.
Read more in the :ref:`User Guide <visualizations>`.
Parameters
----------
precision : ndarray
Precision values.
recall : ndarray
Recall values.
average_precision : float, default=None
Average precision. If None, the average precision is not shown.
estimator_name : str, default=None
Name of estimator. If None, then the estimator name is not shown.
pos_label : str or int, default=None
The class considered as the positive class. If None, the class will not
be shown in the legend.
.. versionadded:: 0.24
Attributes
----------
line_ : matplotlib Artist
Precision recall curve.
ax_ : matplotlib Axes
Axes with precision recall curve.
figure_ : matplotlib Figure
Figure containing the curve.
See Also
--------
precision_recall_curve : Compute precision-recall pairs for different
probability thresholds.
PrecisionRecallDisplay.from_estimator : Plot Precision Recall Curve given
a binary classifier.
PrecisionRecallDisplay.from_predictions : Plot Precision Recall Curve
using predictions from a binary classifier.
Notes
-----
The average precision (cf. :func:`~sklearn.metrics.average_precision`) in
scikit-learn is computed without any interpolation. To be consistent with
this metric, the precision-recall curve is plotted without any
interpolation as well (step-wise style).
You can change this style by passing the keyword argument
`drawstyle="default"` in :meth:`plot`, :meth:`from_estimator`, or
:meth:`from_predictions`. However, the curve will not be strictly
consistent with the reported average precision.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> from sklearn.datasets import make_classification
>>> from sklearn.metrics import (precision_recall_curve,
... PrecisionRecallDisplay)
>>> from sklearn.model_selection import train_test_split
>>> from sklearn.svm import SVC
>>> X, y = make_classification(random_state=0)
>>> X_train, X_test, y_train, y_test = train_test_split(X, y,
... random_state=0)
>>> clf = SVC(random_state=0)
>>> clf.fit(X_train, y_train)
SVC(random_state=0)
>>> predictions = clf.predict(X_test)
>>> precision, recall, _ = precision_recall_curve(y_test, predictions)
>>> disp = PrecisionRecallDisplay(precision=precision, recall=recall)
>>> disp.plot()
<...>
>>> plt.show()
"""
def __init__(
self,
precision,
recall,
*,
average_precision=None,
estimator_name=None,
pos_label=None,
):
self.estimator_name = estimator_name
self.precision = precision
self.recall = recall
self.average_precision = average_precision
self.pos_label = pos_label
def plot(self, ax=None, *, name=None, **kwargs):
"""Plot visualization.
Extra keyword arguments will be passed to matplotlib's `plot`.
Parameters
----------
ax : Matplotlib Axes, default=None
Axes object to plot on. If `None`, a new figure and axes is
created.
name : str, default=None
Name of precision recall curve for labeling. If `None`, use
`estimator_name` if not `None`, otherwise no labeling is shown.
**kwargs : dict
Keyword arguments to be passed to matplotlib's `plot`.
Returns
-------
display : :class:`~sklearn.metrics.PrecisionRecallDisplay`
Object that stores computed values.
Notes
-----
The average precision (cf. :func:`~sklearn.metrics.average_precision`)
in scikit-learn is computed without any interpolation. To be consistent
with this metric, the precision-recall curve is plotted without any
interpolation as well (step-wise style).
You can change this style by passing the keyword argument
`drawstyle="default"`. However, the curve will not be strictly
consistent with the reported average precision.
"""
check_matplotlib_support("PrecisionRecallDisplay.plot")
name = self.estimator_name if name is None else name
line_kwargs = {"drawstyle": "steps-post"}
if self.average_precision is not None and name is not None:
line_kwargs["label"] = f"{name} (AP = {self.average_precision:0.2f})"
elif self.average_precision is not None:
line_kwargs["label"] = f"AP = {self.average_precision:0.2f}"
elif name is not None:
line_kwargs["label"] = name
line_kwargs.update(**kwargs)
import matplotlib.pyplot as plt
if ax is None:
fig, ax = plt.subplots()
(self.line_,) = ax.plot(self.recall, self.precision, **line_kwargs)
info_pos_label = (
f" (Positive label: {self.pos_label})" if self.pos_label is not None else ""
)
xlabel = "Recall" + info_pos_label
ylabel = "Precision" + info_pos_label
ax.set(xlabel=xlabel, ylabel=ylabel)
if "label" in line_kwargs:
ax.legend(loc="lower left")
self.ax_ = ax
self.figure_ = ax.figure
return self
@classmethod
def from_estimator(
cls,
estimator,
X,
y,
*,
sample_weight=None,
pos_label=None,
response_method="auto",
name=None,
ax=None,
**kwargs,
):
"""Plot precision-recall curve given an estimator and some data.
Parameters
----------
estimator : estimator instance
Fitted classifier or a fitted :class:`~sklearn.pipeline.Pipeline`
in which the last estimator is a classifier.
X : {array-like, sparse matrix} of shape (n_samples, n_features)
Input values.
y : array-like of shape (n_samples,)
Target values.
sample_weight : array-like of shape (n_samples,), default=None
Sample weights.
pos_label : str or int, default=None
The class considered as the positive class when computing the
precision and recall metrics. By default, `estimators.classes_[1]`
is considered as the positive class.
response_method : {'predict_proba', 'decision_function', 'auto'}, \
default='auto'
Specifies whether to use :term:`predict_proba` or
:term:`decision_function` as the target response. If set to 'auto',
:term:`predict_proba` is tried first and if it does not exist
:term:`decision_function` is tried next.
name : str, default=None
Name for labeling curve. If `None`, no name is used.
ax : matplotlib axes, default=None
Axes object to plot on. If `None`, a new figure and axes is created.
**kwargs : dict
Keyword arguments to be passed to matplotlib's `plot`.
Returns
-------
display : :class:`~sklearn.metrics.PrecisionRecallDisplay`
See Also
--------
PrecisionRecallDisplay.from_predictions : Plot precision-recall curve
using estimated probabilities or output of decision function.
Notes
-----
The average precision (cf. :func:`~sklearn.metrics.average_precision`)
in scikit-learn is computed without any interpolation. To be consistent
with this metric, the precision-recall curve is plotted without any
interpolation as well (step-wise style).
You can change this style by passing the keyword argument
`drawstyle="default"`. However, the curve will not be strictly
consistent with the reported average precision.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> from sklearn.datasets import make_classification
>>> from sklearn.metrics import PrecisionRecallDisplay
>>> from sklearn.model_selection import train_test_split
>>> from sklearn.linear_model import LogisticRegression
>>> X, y = make_classification(random_state=0)
>>> X_train, X_test, y_train, y_test = train_test_split(
... X, y, random_state=0)
>>> clf = LogisticRegression()
>>> clf.fit(X_train, y_train)
LogisticRegression()
>>> PrecisionRecallDisplay.from_estimator(
... clf, X_test, y_test)
<...>
>>> plt.show()
"""
method_name = f"{cls.__name__}.from_estimator"
check_matplotlib_support(method_name)
if not is_classifier(estimator):
raise ValueError(f"{method_name} only supports classifiers")
y_pred, pos_label = _get_response(
X,
estimator,
response_method,
pos_label=pos_label,
)
name = name if name is not None else estimator.__class__.__name__
return cls.from_predictions(
y,
y_pred,
sample_weight=sample_weight,
name=name,
pos_label=pos_label,
ax=ax,
**kwargs,
)
@classmethod
def from_predictions(
cls,
y_true,
y_pred,
*,
sample_weight=None,
pos_label=None,
name=None,
ax=None,
**kwargs,
):
"""Plot precision-recall curve given binary class predictions.
Parameters
----------
y_true : array-like of shape (n_samples,)
True binary labels.
y_pred : array-like of shape (n_samples,)
Estimated probabilities or output of decision function.
sample_weight : array-like of shape (n_samples,), default=None
Sample weights.
pos_label : str or int, default=None
The class considered as the positive class when computing the
precision and recall metrics.
name : str, default=None
Name for labeling curve. If `None`, name will be set to
`"Classifier"`.
ax : matplotlib axes, default=None
Axes object to plot on. If `None`, a new figure and axes is created.
**kwargs : dict
Keyword arguments to be passed to matplotlib's `plot`.
Returns
-------
display : :class:`~sklearn.metrics.PrecisionRecallDisplay`
See Also
--------
PrecisionRecallDisplay.from_estimator : Plot precision-recall curve
using an estimator.
Notes
-----
The average precision (cf. :func:`~sklearn.metrics.average_precision`)
in scikit-learn is computed without any interpolation. To be consistent
with this metric, the precision-recall curve is plotted without any
interpolation as well (step-wise style).
You can change this style by passing the keyword argument
`drawstyle="default"`. However, the curve will not be strictly
consistent with the reported average precision.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> from sklearn.datasets import make_classification
>>> from sklearn.metrics import PrecisionRecallDisplay
>>> from sklearn.model_selection import train_test_split
>>> from sklearn.linear_model import LogisticRegression
>>> X, y = make_classification(random_state=0)
>>> X_train, X_test, y_train, y_test = train_test_split(
... X, y, random_state=0)
>>> clf = LogisticRegression()
>>> clf.fit(X_train, y_train)
LogisticRegression()
>>> y_pred = clf.predict_proba(X_test)[:, 1]
>>> PrecisionRecallDisplay.from_predictions(
... y_test, y_pred)
<...>
>>> plt.show()
"""
check_matplotlib_support(f"{cls.__name__}.from_predictions")
check_consistent_length(y_true, y_pred, sample_weight)
pos_label = _check_pos_label_consistency(pos_label, y_true)
precision, recall, _ = precision_recall_curve(
y_true, y_pred, pos_label=pos_label, sample_weight=sample_weight
)
average_precision = average_precision_score(
y_true, y_pred, pos_label=pos_label, sample_weight=sample_weight
)
name = name if name is not None else "Classifier"
viz = PrecisionRecallDisplay(
precision=precision,
recall=recall,
average_precision=average_precision,
estimator_name=name,
pos_label=pos_label,
)
return viz.plot(ax=ax, name=name, **kwargs)
@deprecated(
"Function `plot_precision_recall_curve` is deprecated in 1.0 and will be "
"removed in 1.2. Use one of the class methods: "
"PrecisionRecallDisplay.from_predictions or "
"PrecisionRecallDisplay.from_estimator."
)
def plot_precision_recall_curve(
estimator,
X,
y,
*,
sample_weight=None,
response_method="auto",
name=None,
ax=None,
pos_label=None,
**kwargs,
):
"""Plot Precision Recall Curve for binary classifiers.
Extra keyword arguments will be passed to matplotlib's `plot`.
Read more in the :ref:`User Guide <precision_recall_f_measure_metrics>`.
.. deprecated:: 1.0
`plot_precision_recall_curve` is deprecated in 1.0 and will be removed in
1.2. Use one of the following class methods:
:func:`~sklearn.metrics.PrecisionRecallDisplay.from_predictions` or
:func:`~sklearn.metrics.PrecisionRecallDisplay.from_estimator`.
Parameters
----------
estimator : estimator instance
Fitted classifier or a fitted :class:`~sklearn.pipeline.Pipeline`
in which the last estimator is a classifier.
X : {array-like, sparse matrix} of shape (n_samples, n_features)
Input values.
y : array-like of shape (n_samples,)
Binary target values.
sample_weight : array-like of shape (n_samples,), default=None
Sample weights.
response_method : {'predict_proba', 'decision_function', 'auto'}, \
default='auto'
Specifies whether to use :term:`predict_proba` or
:term:`decision_function` as the target response. If set to 'auto',
:term:`predict_proba` is tried first and if it does not exist
:term:`decision_function` is tried next.
name : str, default=None
Name for labeling curve. If `None`, the name of the
estimator is used.
ax : matplotlib axes, default=None
Axes object to plot on. If `None`, a new figure and axes is created.
pos_label : str or int, default=None
The class considered as the positive class when computing the precision
and recall metrics. By default, `estimators.classes_[1]` is considered
as the positive class.
.. versionadded:: 0.24
**kwargs : dict
Keyword arguments to be passed to matplotlib's `plot`.
Returns
-------
display : :class:`~sklearn.metrics.PrecisionRecallDisplay`
Object that stores computed values.
See Also
--------
precision_recall_curve : Compute precision-recall pairs for different
probability thresholds.
PrecisionRecallDisplay : Precision Recall visualization.
"""
check_matplotlib_support("plot_precision_recall_curve")
y_pred, pos_label = _get_response(
X, estimator, response_method, pos_label=pos_label
)
precision, recall, _ = precision_recall_curve(
y, y_pred, pos_label=pos_label, sample_weight=sample_weight
)
average_precision = average_precision_score(
y, y_pred, pos_label=pos_label, sample_weight=sample_weight
)
name = name if name is not None else estimator.__class__.__name__
viz = PrecisionRecallDisplay(
precision=precision,
recall=recall,
average_precision=average_precision,
estimator_name=name,
pos_label=pos_label,
)
return viz.plot(ax=ax, name=name, **kwargs)

View File

@@ -0,0 +1,470 @@
from .base import _get_response
from .. import auc
from .. import roc_curve
from .._base import _check_pos_label_consistency
from ...utils import check_matplotlib_support, deprecated
class RocCurveDisplay:
"""ROC Curve visualization.
It is recommend to use
:func:`~sklearn.metrics.RocCurveDisplay.from_estimator` or
:func:`~sklearn.metrics.RocCurveDisplay.from_predictions` to create
a :class:`~sklearn.metrics.RocCurveDisplay`. All parameters are
stored as attributes.
Read more in the :ref:`User Guide <visualizations>`.
Parameters
----------
fpr : ndarray
False positive rate.
tpr : ndarray
True positive rate.
roc_auc : float, default=None
Area under ROC curve. If None, the roc_auc score is not shown.
estimator_name : str, default=None
Name of estimator. If None, the estimator name is not shown.
pos_label : str or int, default=None
The class considered as the positive class when computing the roc auc
metrics. By default, `estimators.classes_[1]` is considered
as the positive class.
.. versionadded:: 0.24
Attributes
----------
line_ : matplotlib Artist
ROC Curve.
ax_ : matplotlib Axes
Axes with ROC Curve.
figure_ : matplotlib Figure
Figure containing the curve.
See Also
--------
roc_curve : Compute Receiver operating characteristic (ROC) curve.
RocCurveDisplay.from_estimator : Plot Receiver Operating Characteristic
(ROC) curve given an estimator and some data.
RocCurveDisplay.from_predictions : Plot Receiver Operating Characteristic
(ROC) curve given the true and predicted values.
roc_auc_score : Compute the area under the ROC curve.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> import numpy as np
>>> from sklearn import metrics
>>> y = np.array([0, 0, 1, 1])
>>> pred = np.array([0.1, 0.4, 0.35, 0.8])
>>> fpr, tpr, thresholds = metrics.roc_curve(y, pred)
>>> roc_auc = metrics.auc(fpr, tpr)
>>> display = metrics.RocCurveDisplay(fpr=fpr, tpr=tpr, roc_auc=roc_auc,
... estimator_name='example estimator')
>>> display.plot()
<...>
>>> plt.show()
"""
def __init__(self, *, fpr, tpr, roc_auc=None, estimator_name=None, pos_label=None):
self.estimator_name = estimator_name
self.fpr = fpr
self.tpr = tpr
self.roc_auc = roc_auc
self.pos_label = pos_label
def plot(self, ax=None, *, name=None, **kwargs):
"""Plot visualization
Extra keyword arguments will be passed to matplotlib's ``plot``.
Parameters
----------
ax : matplotlib axes, default=None
Axes object to plot on. If `None`, a new figure and axes is
created.
name : str, default=None
Name of ROC Curve for labeling. If `None`, use `estimator_name` if
not `None`, otherwise no labeling is shown.
Returns
-------
display : :class:`~sklearn.metrics.plot.RocCurveDisplay`
Object that stores computed values.
"""
check_matplotlib_support("RocCurveDisplay.plot")
name = self.estimator_name if name is None else name
line_kwargs = {}
if self.roc_auc is not None and name is not None:
line_kwargs["label"] = f"{name} (AUC = {self.roc_auc:0.2f})"
elif self.roc_auc is not None:
line_kwargs["label"] = f"AUC = {self.roc_auc:0.2f}"
elif name is not None:
line_kwargs["label"] = name
line_kwargs.update(**kwargs)
import matplotlib.pyplot as plt
if ax is None:
fig, ax = plt.subplots()
(self.line_,) = ax.plot(self.fpr, self.tpr, **line_kwargs)
info_pos_label = (
f" (Positive label: {self.pos_label})" if self.pos_label is not None else ""
)
xlabel = "False Positive Rate" + info_pos_label
ylabel = "True Positive Rate" + info_pos_label
ax.set(xlabel=xlabel, ylabel=ylabel)
if "label" in line_kwargs:
ax.legend(loc="lower right")
self.ax_ = ax
self.figure_ = ax.figure
return self
@classmethod
def from_estimator(
cls,
estimator,
X,
y,
*,
sample_weight=None,
drop_intermediate=True,
response_method="auto",
pos_label=None,
name=None,
ax=None,
**kwargs,
):
"""Create a ROC Curve display from an estimator.
Parameters
----------
estimator : estimator instance
Fitted classifier or a fitted :class:`~sklearn.pipeline.Pipeline`
in which the last estimator is a classifier.
X : {array-like, sparse matrix} of shape (n_samples, n_features)
Input values.
y : array-like of shape (n_samples,)
Target values.
sample_weight : array-like of shape (n_samples,), default=None
Sample weights.
drop_intermediate : bool, default=True
Whether to drop some suboptimal thresholds which would not appear
on a plotted ROC curve. This is useful in order to create lighter
ROC curves.
response_method : {'predict_proba', 'decision_function', 'auto'} \
default='auto'
Specifies whether to use :term:`predict_proba` or
:term:`decision_function` as the target response. If set to 'auto',
:term:`predict_proba` is tried first and if it does not exist
:term:`decision_function` is tried next.
pos_label : str or int, default=None
The class considered as the positive class when computing the roc auc
metrics. By default, `estimators.classes_[1]` is considered
as the positive class.
name : str, default=None
Name of ROC Curve for labeling. If `None`, use the name of the
estimator.
ax : matplotlib axes, default=None
Axes object to plot on. If `None`, a new figure and axes is created.
**kwargs : dict
Keyword arguments to be passed to matplotlib's `plot`.
Returns
-------
display : :class:`~sklearn.metrics.plot.RocCurveDisplay`
The ROC Curve display.
See Also
--------
roc_curve : Compute Receiver operating characteristic (ROC) curve.
RocCurveDisplay.from_predictions : ROC Curve visualization given the
probabilities of scores of a classifier.
roc_auc_score : Compute the area under the ROC curve.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> from sklearn.datasets import make_classification
>>> from sklearn.metrics import RocCurveDisplay
>>> from sklearn.model_selection import train_test_split
>>> from sklearn.svm import SVC
>>> X, y = make_classification(random_state=0)
>>> X_train, X_test, y_train, y_test = train_test_split(
... X, y, random_state=0)
>>> clf = SVC(random_state=0).fit(X_train, y_train)
>>> RocCurveDisplay.from_estimator(
... clf, X_test, y_test)
<...>
>>> plt.show()
"""
check_matplotlib_support(f"{cls.__name__}.from_estimator")
name = estimator.__class__.__name__ if name is None else name
y_pred, pos_label = _get_response(
X,
estimator,
response_method=response_method,
pos_label=pos_label,
)
return cls.from_predictions(
y_true=y,
y_pred=y_pred,
sample_weight=sample_weight,
drop_intermediate=drop_intermediate,
name=name,
ax=ax,
pos_label=pos_label,
**kwargs,
)
@classmethod
def from_predictions(
cls,
y_true,
y_pred,
*,
sample_weight=None,
drop_intermediate=True,
pos_label=None,
name=None,
ax=None,
**kwargs,
):
"""Plot ROC curve given the true and predicted values.
Read more in the :ref:`User Guide <visualizations>`.
.. versionadded:: 1.0
Parameters
----------
y_true : array-like of shape (n_samples,)
True labels.
y_pred : array-like of shape (n_samples,)
Target scores, can either be probability estimates of the positive
class, confidence values, or non-thresholded measure of decisions
(as returned by “decision_function” on some classifiers).
sample_weight : array-like of shape (n_samples,), default=None
Sample weights.
drop_intermediate : bool, default=True
Whether to drop some suboptimal thresholds which would not appear
on a plotted ROC curve. This is useful in order to create lighter
ROC curves.
pos_label : str or int, default=None
The label of the positive class. When `pos_label=None`, if `y_true`
is in {-1, 1} or {0, 1}, `pos_label` is set to 1, otherwise an
error will be raised.
name : str, default=None
Name of ROC curve for labeling. If `None`, name will be set to
`"Classifier"`.
ax : matplotlib axes, default=None
Axes object to plot on. If `None`, a new figure and axes is
created.
**kwargs : dict
Additional keywords arguments passed to matplotlib `plot` function.
Returns
-------
display : :class:`~sklearn.metrics.RocCurveDisplay`
Object that stores computed values.
See Also
--------
roc_curve : Compute Receiver operating characteristic (ROC) curve.
RocCurveDisplay.from_estimator : ROC Curve visualization given an
estimator and some data.
roc_auc_score : Compute the area under the ROC curve.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> from sklearn.datasets import make_classification
>>> from sklearn.metrics import RocCurveDisplay
>>> from sklearn.model_selection import train_test_split
>>> from sklearn.svm import SVC
>>> X, y = make_classification(random_state=0)
>>> X_train, X_test, y_train, y_test = train_test_split(
... X, y, random_state=0)
>>> clf = SVC(random_state=0).fit(X_train, y_train)
>>> y_pred = clf.decision_function(X_test)
>>> RocCurveDisplay.from_predictions(
... y_test, y_pred)
<...>
>>> plt.show()
"""
check_matplotlib_support(f"{cls.__name__}.from_predictions")
fpr, tpr, _ = roc_curve(
y_true,
y_pred,
pos_label=pos_label,
sample_weight=sample_weight,
drop_intermediate=drop_intermediate,
)
roc_auc = auc(fpr, tpr)
name = "Classifier" if name is None else name
pos_label = _check_pos_label_consistency(pos_label, y_true)
viz = RocCurveDisplay(
fpr=fpr, tpr=tpr, roc_auc=roc_auc, estimator_name=name, pos_label=pos_label
)
return viz.plot(ax=ax, name=name, **kwargs)
@deprecated(
"Function :func:`plot_roc_curve` is deprecated in 1.0 and will be "
"removed in 1.2. Use one of the class methods: "
":meth:`sklearn.metric.RocCurveDisplay.from_predictions` or "
":meth:`sklearn.metric.RocCurveDisplay.from_estimator`."
)
def plot_roc_curve(
estimator,
X,
y,
*,
sample_weight=None,
drop_intermediate=True,
response_method="auto",
name=None,
ax=None,
pos_label=None,
**kwargs,
):
"""Plot Receiver operating characteristic (ROC) curve.
Extra keyword arguments will be passed to matplotlib's `plot`.
Read more in the :ref:`User Guide <visualizations>`.
Parameters
----------
estimator : estimator instance
Fitted classifier or a fitted :class:`~sklearn.pipeline.Pipeline`
in which the last estimator is a classifier.
X : {array-like, sparse matrix} of shape (n_samples, n_features)
Input values.
y : array-like of shape (n_samples,)
Target values.
sample_weight : array-like of shape (n_samples,), default=None
Sample weights.
drop_intermediate : bool, default=True
Whether to drop some suboptimal thresholds which would not appear
on a plotted ROC curve. This is useful in order to create lighter
ROC curves.
response_method : {'predict_proba', 'decision_function', 'auto'} \
default='auto'
Specifies whether to use :term:`predict_proba` or
:term:`decision_function` as the target response. If set to 'auto',
:term:`predict_proba` is tried first and if it does not exist
:term:`decision_function` is tried next.
name : str, default=None
Name of ROC Curve for labeling. If `None`, use the name of the
estimator.
ax : matplotlib axes, default=None
Axes object to plot on. If `None`, a new figure and axes is created.
pos_label : str or int, default=None
The class considered as the positive class when computing the roc auc
metrics. By default, `estimators.classes_[1]` is considered
as the positive class.
**kwargs : dict
Additional keywords arguments passed to matplotlib `plot` function.
.. versionadded:: 0.24
Returns
-------
display : :class:`~sklearn.metrics.RocCurveDisplay`
Object that stores computed values.
See Also
--------
roc_curve : Compute Receiver operating characteristic (ROC) curve.
RocCurveDisplay.from_estimator : ROC Curve visualization given an estimator
and some data.
RocCurveDisplay.from_predictions : ROC Curve visualisation given the
true and predicted values.
roc_auc_score : Compute the area under the ROC curve.
Examples
--------
>>> import matplotlib.pyplot as plt
>>> from sklearn import datasets, metrics, model_selection, svm
>>> X, y = datasets.make_classification(random_state=0)
>>> X_train, X_test, y_train, y_test = model_selection.train_test_split(
... X, y, random_state=0)
>>> clf = svm.SVC(random_state=0)
>>> clf.fit(X_train, y_train)
SVC(random_state=0)
>>> metrics.plot_roc_curve(clf, X_test, y_test) # doctest: +SKIP
<...>
>>> plt.show()
"""
check_matplotlib_support("plot_roc_curve")
y_pred, pos_label = _get_response(
X, estimator, response_method, pos_label=pos_label
)
fpr, tpr, _ = roc_curve(
y,
y_pred,
pos_label=pos_label,
sample_weight=sample_weight,
drop_intermediate=drop_intermediate,
)
roc_auc = auc(fpr, tpr)
name = estimator.__class__.__name__ if name is None else name
viz = RocCurveDisplay(
fpr=fpr, tpr=tpr, roc_auc=roc_auc, estimator_name=name, pos_label=pos_label
)
return viz.plot(ax=ax, name=name, **kwargs)

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import numpy as np
import pytest
from sklearn.datasets import load_iris
from sklearn.linear_model import LogisticRegression
from sklearn.tree import DecisionTreeClassifier, DecisionTreeRegressor
from sklearn.metrics._plot.base import _get_response
@pytest.mark.parametrize(
"estimator, err_msg, params",
[
(
DecisionTreeRegressor(),
"Expected 'estimator' to be a binary classifier",
{"response_method": "auto"},
),
(
DecisionTreeClassifier(),
"The class provided by 'pos_label' is unknown.",
{"response_method": "auto", "pos_label": "unknown"},
),
(
DecisionTreeClassifier(),
"fit on multiclass",
{"response_method": "predict_proba"},
),
],
)
def test_get_response_error(estimator, err_msg, params):
"""Check that we raise the proper error messages in `_get_response`."""
X, y = load_iris(return_X_y=True)
estimator.fit(X, y)
with pytest.raises(ValueError, match=err_msg):
_get_response(X, estimator, **params)
def test_get_response_predict_proba():
"""Check the behaviour of `_get_response` using `predict_proba`."""
X, y = load_iris(return_X_y=True)
X_binary, y_binary = X[:100], y[:100]
classifier = DecisionTreeClassifier().fit(X_binary, y_binary)
y_proba, pos_label = _get_response(
X_binary, classifier, response_method="predict_proba"
)
np.testing.assert_allclose(y_proba, classifier.predict_proba(X_binary)[:, 1])
assert pos_label == 1
y_proba, pos_label = _get_response(
X_binary, classifier, response_method="predict_proba", pos_label=0
)
np.testing.assert_allclose(y_proba, classifier.predict_proba(X_binary)[:, 0])
assert pos_label == 0
def test_get_response_decision_function():
"""Check the behaviour of `get_response` using `decision_function`."""
X, y = load_iris(return_X_y=True)
X_binary, y_binary = X[:100], y[:100]
classifier = LogisticRegression().fit(X_binary, y_binary)
y_score, pos_label = _get_response(
X_binary, classifier, response_method="decision_function"
)
np.testing.assert_allclose(y_score, classifier.decision_function(X_binary))
assert pos_label == 1
y_score, pos_label = _get_response(
X_binary, classifier, response_method="decision_function", pos_label=0
)
np.testing.assert_allclose(y_score, classifier.decision_function(X_binary) * -1)
assert pos_label == 0

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import pytest
from sklearn.base import ClassifierMixin, clone
from sklearn.compose import make_column_transformer
from sklearn.datasets import load_iris
from sklearn.exceptions import NotFittedError
from sklearn.linear_model import LogisticRegression
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.tree import DecisionTreeClassifier
from sklearn.metrics import (
DetCurveDisplay,
PrecisionRecallDisplay,
RocCurveDisplay,
)
@pytest.fixture(scope="module")
def data():
return load_iris(return_X_y=True)
@pytest.fixture(scope="module")
def data_binary(data):
X, y = data
return X[y < 2], y[y < 2]
@pytest.mark.parametrize(
"Display", [DetCurveDisplay, PrecisionRecallDisplay, RocCurveDisplay]
)
def test_display_curve_error_non_binary(pyplot, data, Display):
"""Check that a proper error is raised when only binary classification is
supported."""
X, y = data
clf = DecisionTreeClassifier().fit(X, y)
msg = (
"Expected 'estimator' to be a binary classifier, but got DecisionTreeClassifier"
)
with pytest.raises(ValueError, match=msg):
Display.from_estimator(clf, X, y)
@pytest.mark.parametrize(
"response_method, msg",
[
(
"predict_proba",
"response method predict_proba is not defined in MyClassifier",
),
(
"decision_function",
"response method decision_function is not defined in MyClassifier",
),
(
"auto",
"response method decision_function or predict_proba is not "
"defined in MyClassifier",
),
(
"bad_method",
"response_method must be 'predict_proba', 'decision_function' or 'auto'",
),
],
)
@pytest.mark.parametrize(
"Display", [DetCurveDisplay, PrecisionRecallDisplay, RocCurveDisplay]
)
def test_display_curve_error_no_response(
pyplot,
data_binary,
response_method,
msg,
Display,
):
"""Check that a proper error is raised when the response method requested
is not defined for the given trained classifier."""
X, y = data_binary
class MyClassifier(ClassifierMixin):
def fit(self, X, y):
self.classes_ = [0, 1]
return self
clf = MyClassifier().fit(X, y)
with pytest.raises(ValueError, match=msg):
Display.from_estimator(clf, X, y, response_method=response_method)
@pytest.mark.parametrize(
"Display", [DetCurveDisplay, PrecisionRecallDisplay, RocCurveDisplay]
)
@pytest.mark.parametrize("constructor_name", ["from_estimator", "from_predictions"])
def test_display_curve_estimator_name_multiple_calls(
pyplot,
data_binary,
Display,
constructor_name,
):
"""Check that passing `name` when calling `plot` will overwrite the original name
in the legend."""
X, y = data_binary
clf_name = "my hand-crafted name"
clf = LogisticRegression().fit(X, y)
y_pred = clf.predict_proba(X)[:, 1]
# safe guard for the binary if/else construction
assert constructor_name in ("from_estimator", "from_predictions")
if constructor_name == "from_estimator":
disp = Display.from_estimator(clf, X, y, name=clf_name)
else:
disp = Display.from_predictions(y, y_pred, name=clf_name)
assert disp.estimator_name == clf_name
pyplot.close("all")
disp.plot()
assert clf_name in disp.line_.get_label()
pyplot.close("all")
clf_name = "another_name"
disp.plot(name=clf_name)
assert clf_name in disp.line_.get_label()
@pytest.mark.parametrize(
"clf",
[
LogisticRegression(),
make_pipeline(StandardScaler(), LogisticRegression()),
make_pipeline(
make_column_transformer((StandardScaler(), [0, 1])), LogisticRegression()
),
],
)
@pytest.mark.parametrize(
"Display", [DetCurveDisplay, PrecisionRecallDisplay, RocCurveDisplay]
)
def test_display_curve_not_fitted_errors(pyplot, data_binary, clf, Display):
"""Check that a proper error is raised when the classifier is not
fitted."""
X, y = data_binary
# clone since we parametrize the test and the classifier will be fitted
# when testing the second and subsequent plotting function
model = clone(clf)
with pytest.raises(NotFittedError):
Display.from_estimator(model, X, y)
model.fit(X, y)
disp = Display.from_estimator(model, X, y)
assert model.__class__.__name__ in disp.line_.get_label()
assert disp.estimator_name == model.__class__.__name__

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from numpy.testing import (
assert_allclose,
assert_array_equal,
)
import numpy as np
import pytest
from sklearn.datasets import make_classification
from sklearn.compose import make_column_transformer
from sklearn.exceptions import NotFittedError
from sklearn.linear_model import LogisticRegression
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.svm import SVC, SVR
from sklearn.metrics import ConfusionMatrixDisplay
from sklearn.metrics import confusion_matrix
# TODO: Remove when https://github.com/numpy/numpy/issues/14397 is resolved
pytestmark = pytest.mark.filterwarnings(
"ignore:In future, it will be an error for 'np.bool_':DeprecationWarning:"
"matplotlib.*"
)
def test_confusion_matrix_display_validation(pyplot):
"""Check that we raise the proper error when validating parameters."""
X, y = make_classification(
n_samples=100, n_informative=5, n_classes=5, random_state=0
)
with pytest.raises(NotFittedError):
ConfusionMatrixDisplay.from_estimator(SVC(), X, y)
regressor = SVR().fit(X, y)
y_pred_regressor = regressor.predict(X)
y_pred_classifier = SVC().fit(X, y).predict(X)
err_msg = "ConfusionMatrixDisplay.from_estimator only supports classifiers"
with pytest.raises(ValueError, match=err_msg):
ConfusionMatrixDisplay.from_estimator(regressor, X, y)
err_msg = "Mix type of y not allowed, got types"
with pytest.raises(ValueError, match=err_msg):
# Force `y_true` to be seen as a regression problem
ConfusionMatrixDisplay.from_predictions(y + 0.5, y_pred_classifier)
with pytest.raises(ValueError, match=err_msg):
ConfusionMatrixDisplay.from_predictions(y, y_pred_regressor)
err_msg = "Found input variables with inconsistent numbers of samples"
with pytest.raises(ValueError, match=err_msg):
ConfusionMatrixDisplay.from_predictions(y, y_pred_classifier[::2])
@pytest.mark.parametrize("constructor_name", ["from_estimator", "from_predictions"])
def test_confusion_matrix_display_invalid_option(pyplot, constructor_name):
"""Check the error raise if an invalid parameter value is passed."""
X, y = make_classification(
n_samples=100, n_informative=5, n_classes=5, random_state=0
)
classifier = SVC().fit(X, y)
y_pred = classifier.predict(X)
# safe guard for the binary if/else construction
assert constructor_name in ("from_estimator", "from_predictions")
extra_params = {"normalize": "invalid"}
err_msg = r"normalize must be one of \{'true', 'pred', 'all', None\}"
with pytest.raises(ValueError, match=err_msg):
if constructor_name == "from_estimator":
ConfusionMatrixDisplay.from_estimator(classifier, X, y, **extra_params)
else:
ConfusionMatrixDisplay.from_predictions(y, y_pred, **extra_params)
@pytest.mark.parametrize("constructor_name", ["from_estimator", "from_predictions"])
@pytest.mark.parametrize("with_labels", [True, False])
@pytest.mark.parametrize("with_display_labels", [True, False])
def test_confusion_matrix_display_custom_labels(
pyplot, constructor_name, with_labels, with_display_labels
):
"""Check the resulting plot when labels are given."""
n_classes = 5
X, y = make_classification(
n_samples=100, n_informative=5, n_classes=n_classes, random_state=0
)
classifier = SVC().fit(X, y)
y_pred = classifier.predict(X)
# safe guard for the binary if/else construction
assert constructor_name in ("from_estimator", "from_predictions")
ax = pyplot.gca()
labels = [2, 1, 0, 3, 4] if with_labels else None
display_labels = ["b", "d", "a", "e", "f"] if with_display_labels else None
cm = confusion_matrix(y, y_pred, labels=labels)
common_kwargs = {
"ax": ax,
"display_labels": display_labels,
"labels": labels,
}
if constructor_name == "from_estimator":
disp = ConfusionMatrixDisplay.from_estimator(classifier, X, y, **common_kwargs)
else:
disp = ConfusionMatrixDisplay.from_predictions(y, y_pred, **common_kwargs)
assert_allclose(disp.confusion_matrix, cm)
if with_display_labels:
expected_display_labels = display_labels
elif with_labels:
expected_display_labels = labels
else:
expected_display_labels = list(range(n_classes))
expected_display_labels_str = [str(name) for name in expected_display_labels]
x_ticks = [tick.get_text() for tick in disp.ax_.get_xticklabels()]
y_ticks = [tick.get_text() for tick in disp.ax_.get_yticklabels()]
assert_array_equal(disp.display_labels, expected_display_labels)
assert_array_equal(x_ticks, expected_display_labels_str)
assert_array_equal(y_ticks, expected_display_labels_str)
@pytest.mark.parametrize("constructor_name", ["from_estimator", "from_predictions"])
@pytest.mark.parametrize("normalize", ["true", "pred", "all", None])
@pytest.mark.parametrize("include_values", [True, False])
def test_confusion_matrix_display_plotting(
pyplot,
constructor_name,
normalize,
include_values,
):
"""Check the overall plotting rendering."""
n_classes = 5
X, y = make_classification(
n_samples=100, n_informative=5, n_classes=n_classes, random_state=0
)
classifier = SVC().fit(X, y)
y_pred = classifier.predict(X)
# safe guard for the binary if/else construction
assert constructor_name in ("from_estimator", "from_predictions")
ax = pyplot.gca()
cmap = "plasma"
cm = confusion_matrix(y, y_pred)
common_kwargs = {
"normalize": normalize,
"cmap": cmap,
"ax": ax,
"include_values": include_values,
}
if constructor_name == "from_estimator":
disp = ConfusionMatrixDisplay.from_estimator(classifier, X, y, **common_kwargs)
else:
disp = ConfusionMatrixDisplay.from_predictions(y, y_pred, **common_kwargs)
assert disp.ax_ == ax
if normalize == "true":
cm = cm / cm.sum(axis=1, keepdims=True)
elif normalize == "pred":
cm = cm / cm.sum(axis=0, keepdims=True)
elif normalize == "all":
cm = cm / cm.sum()
assert_allclose(disp.confusion_matrix, cm)
import matplotlib as mpl
assert isinstance(disp.im_, mpl.image.AxesImage)
assert disp.im_.get_cmap().name == cmap
assert isinstance(disp.ax_, pyplot.Axes)
assert isinstance(disp.figure_, pyplot.Figure)
assert disp.ax_.get_ylabel() == "True label"
assert disp.ax_.get_xlabel() == "Predicted label"
x_ticks = [tick.get_text() for tick in disp.ax_.get_xticklabels()]
y_ticks = [tick.get_text() for tick in disp.ax_.get_yticklabels()]
expected_display_labels = list(range(n_classes))
expected_display_labels_str = [str(name) for name in expected_display_labels]
assert_array_equal(disp.display_labels, expected_display_labels)
assert_array_equal(x_ticks, expected_display_labels_str)
assert_array_equal(y_ticks, expected_display_labels_str)
image_data = disp.im_.get_array().data
assert_allclose(image_data, cm)
if include_values:
assert disp.text_.shape == (n_classes, n_classes)
fmt = ".2g"
expected_text = np.array([format(v, fmt) for v in cm.ravel(order="C")])
text_text = np.array([t.get_text() for t in disp.text_.ravel(order="C")])
assert_array_equal(expected_text, text_text)
else:
assert disp.text_ is None
@pytest.mark.parametrize("constructor_name", ["from_estimator", "from_predictions"])
def test_confusion_matrix_display(pyplot, constructor_name):
"""Check the behaviour of the default constructor without using the class
methods."""
n_classes = 5
X, y = make_classification(
n_samples=100, n_informative=5, n_classes=n_classes, random_state=0
)
classifier = SVC().fit(X, y)
y_pred = classifier.predict(X)
# safe guard for the binary if/else construction
assert constructor_name in ("from_estimator", "from_predictions")
cm = confusion_matrix(y, y_pred)
common_kwargs = {
"normalize": None,
"include_values": True,
"cmap": "viridis",
"xticks_rotation": 45.0,
}
if constructor_name == "from_estimator":
disp = ConfusionMatrixDisplay.from_estimator(classifier, X, y, **common_kwargs)
else:
disp = ConfusionMatrixDisplay.from_predictions(y, y_pred, **common_kwargs)
assert_allclose(disp.confusion_matrix, cm)
assert disp.text_.shape == (n_classes, n_classes)
rotations = [tick.get_rotation() for tick in disp.ax_.get_xticklabels()]
assert_allclose(rotations, 45.0)
image_data = disp.im_.get_array().data
assert_allclose(image_data, cm)
disp.plot(cmap="plasma")
assert disp.im_.get_cmap().name == "plasma"
disp.plot(include_values=False)
assert disp.text_ is None
disp.plot(xticks_rotation=90.0)
rotations = [tick.get_rotation() for tick in disp.ax_.get_xticklabels()]
assert_allclose(rotations, 90.0)
disp.plot(values_format="e")
expected_text = np.array([format(v, "e") for v in cm.ravel(order="C")])
text_text = np.array([t.get_text() for t in disp.text_.ravel(order="C")])
assert_array_equal(expected_text, text_text)
def test_confusion_matrix_contrast(pyplot):
"""Check that the text color is appropriate depending on background."""
cm = np.eye(2) / 2
disp = ConfusionMatrixDisplay(cm, display_labels=[0, 1])
disp.plot(cmap=pyplot.cm.gray)
# diagonal text is black
assert_allclose(disp.text_[0, 0].get_color(), [0.0, 0.0, 0.0, 1.0])
assert_allclose(disp.text_[1, 1].get_color(), [0.0, 0.0, 0.0, 1.0])
# off-diagonal text is white
assert_allclose(disp.text_[0, 1].get_color(), [1.0, 1.0, 1.0, 1.0])
assert_allclose(disp.text_[1, 0].get_color(), [1.0, 1.0, 1.0, 1.0])
disp.plot(cmap=pyplot.cm.gray_r)
# diagonal text is white
assert_allclose(disp.text_[0, 1].get_color(), [0.0, 0.0, 0.0, 1.0])
assert_allclose(disp.text_[1, 0].get_color(), [0.0, 0.0, 0.0, 1.0])
# off-diagonal text is black
assert_allclose(disp.text_[0, 0].get_color(), [1.0, 1.0, 1.0, 1.0])
assert_allclose(disp.text_[1, 1].get_color(), [1.0, 1.0, 1.0, 1.0])
# Regression test for #15920
cm = np.array([[19, 34], [32, 58]])
disp = ConfusionMatrixDisplay(cm, display_labels=[0, 1])
disp.plot(cmap=pyplot.cm.Blues)
min_color = pyplot.cm.Blues(0)
max_color = pyplot.cm.Blues(255)
assert_allclose(disp.text_[0, 0].get_color(), max_color)
assert_allclose(disp.text_[0, 1].get_color(), max_color)
assert_allclose(disp.text_[1, 0].get_color(), max_color)
assert_allclose(disp.text_[1, 1].get_color(), min_color)
@pytest.mark.parametrize(
"clf",
[
LogisticRegression(),
make_pipeline(StandardScaler(), LogisticRegression()),
make_pipeline(
make_column_transformer((StandardScaler(), [0, 1])),
LogisticRegression(),
),
],
ids=["clf", "pipeline-clf", "pipeline-column_transformer-clf"],
)
def test_confusion_matrix_pipeline(pyplot, clf):
"""Check the behaviour of the plotting with more complex pipeline."""
n_classes = 5
X, y = make_classification(
n_samples=100, n_informative=5, n_classes=n_classes, random_state=0
)
with pytest.raises(NotFittedError):
ConfusionMatrixDisplay.from_estimator(clf, X, y)
clf.fit(X, y)
y_pred = clf.predict(X)
disp = ConfusionMatrixDisplay.from_estimator(clf, X, y)
cm = confusion_matrix(y, y_pred)
assert_allclose(disp.confusion_matrix, cm)
assert disp.text_.shape == (n_classes, n_classes)
@pytest.mark.parametrize("constructor_name", ["from_estimator", "from_predictions"])
def test_confusion_matrix_with_unknown_labels(pyplot, constructor_name):
"""Check that when labels=None, the unique values in `y_pred` and `y_true`
will be used.
Non-regression test for:
https://github.com/scikit-learn/scikit-learn/pull/18405
"""
n_classes = 5
X, y = make_classification(
n_samples=100, n_informative=5, n_classes=n_classes, random_state=0
)
classifier = SVC().fit(X, y)
y_pred = classifier.predict(X)
# create unseen labels in `y_true` not seen during fitting and not present
# in 'classifier.classes_'
y = y + 1
# safe guard for the binary if/else construction
assert constructor_name in ("from_estimator", "from_predictions")
common_kwargs = {"labels": None}
if constructor_name == "from_estimator":
disp = ConfusionMatrixDisplay.from_estimator(classifier, X, y, **common_kwargs)
else:
disp = ConfusionMatrixDisplay.from_predictions(y, y_pred, **common_kwargs)
display_labels = [tick.get_text() for tick in disp.ax_.get_xticklabels()]
expected_labels = [str(i) for i in range(n_classes + 1)]
assert_array_equal(expected_labels, display_labels)
def test_colormap_max(pyplot):
"""Check that the max color is used for the color of the text."""
from matplotlib import cm
gray = cm.get_cmap("gray", 1024)
confusion_matrix = np.array([[1.0, 0.0], [0.0, 1.0]])
disp = ConfusionMatrixDisplay(confusion_matrix)
disp.plot(cmap=gray)
color = disp.text_[1, 0].get_color()
assert_allclose(color, [1.0, 1.0, 1.0, 1.0])
def test_im_kw_adjust_vmin_vmax(pyplot):
"""Check that im_kw passes kwargs to imshow"""
confusion_matrix = np.array([[0.48, 0.04], [0.08, 0.4]])
disp = ConfusionMatrixDisplay(confusion_matrix)
disp.plot(im_kw=dict(vmin=0.0, vmax=0.8))
clim = disp.im_.get_clim()
assert clim[0] == pytest.approx(0.0)
assert clim[1] == pytest.approx(0.8)

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import pytest
import numpy as np
from numpy.testing import assert_allclose
from sklearn.datasets import load_iris
from sklearn.linear_model import LogisticRegression
from sklearn.metrics import det_curve
from sklearn.metrics import DetCurveDisplay
@pytest.mark.parametrize("constructor_name", ["from_estimator", "from_predictions"])
@pytest.mark.parametrize("response_method", ["predict_proba", "decision_function"])
@pytest.mark.parametrize("with_sample_weight", [True, False])
@pytest.mark.parametrize("with_strings", [True, False])
def test_det_curve_display(
pyplot, constructor_name, response_method, with_sample_weight, with_strings
):
X, y = load_iris(return_X_y=True)
# Binarize the data with only the two first classes
X, y = X[y < 2], y[y < 2]
pos_label = None
if with_strings:
y = np.array(["c", "b"])[y]
pos_label = "c"
if with_sample_weight:
rng = np.random.RandomState(42)
sample_weight = rng.randint(1, 4, size=(X.shape[0]))
else:
sample_weight = None
lr = LogisticRegression()
lr.fit(X, y)
y_pred = getattr(lr, response_method)(X)
if y_pred.ndim == 2:
y_pred = y_pred[:, 1]
# safe guard for the binary if/else construction
assert constructor_name in ("from_estimator", "from_predictions")
common_kwargs = {
"name": lr.__class__.__name__,
"alpha": 0.8,
"sample_weight": sample_weight,
"pos_label": pos_label,
}
if constructor_name == "from_estimator":
disp = DetCurveDisplay.from_estimator(lr, X, y, **common_kwargs)
else:
disp = DetCurveDisplay.from_predictions(y, y_pred, **common_kwargs)
fpr, fnr, _ = det_curve(
y,
y_pred,
sample_weight=sample_weight,
pos_label=pos_label,
)
assert_allclose(disp.fpr, fpr)
assert_allclose(disp.fnr, fnr)
assert disp.estimator_name == "LogisticRegression"
# cannot fail thanks to pyplot fixture
import matplotlib as mpl # noqal
assert isinstance(disp.line_, mpl.lines.Line2D)
assert disp.line_.get_alpha() == 0.8
assert isinstance(disp.ax_, mpl.axes.Axes)
assert isinstance(disp.figure_, mpl.figure.Figure)
assert disp.line_.get_label() == "LogisticRegression"
expected_pos_label = 1 if pos_label is None else pos_label
expected_ylabel = f"False Negative Rate (Positive label: {expected_pos_label})"
expected_xlabel = f"False Positive Rate (Positive label: {expected_pos_label})"
assert disp.ax_.get_ylabel() == expected_ylabel
assert disp.ax_.get_xlabel() == expected_xlabel
@pytest.mark.parametrize(
"constructor_name, expected_clf_name",
[
("from_estimator", "LogisticRegression"),
("from_predictions", "Classifier"),
],
)
def test_det_curve_display_default_name(
pyplot,
constructor_name,
expected_clf_name,
):
# Check the default name display in the figure when `name` is not provided
X, y = load_iris(return_X_y=True)
# Binarize the data with only the two first classes
X, y = X[y < 2], y[y < 2]
lr = LogisticRegression().fit(X, y)
y_pred = lr.predict_proba(X)[:, 1]
if constructor_name == "from_estimator":
disp = DetCurveDisplay.from_estimator(lr, X, y)
else:
disp = DetCurveDisplay.from_predictions(y, y_pred)
assert disp.estimator_name == expected_clf_name
assert disp.line_.get_label() == expected_clf_name

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# TODO: remove this file when plot_confusion_matrix will be deprecated in 1.2
import pytest
import numpy as np
from numpy.testing import assert_allclose
from numpy.testing import assert_array_equal
from sklearn.compose import make_column_transformer
from sklearn.datasets import make_classification
from sklearn.exceptions import NotFittedError
from sklearn.linear_model import LogisticRegression
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.svm import SVC, SVR
from sklearn.metrics import confusion_matrix
from sklearn.metrics import plot_confusion_matrix
from sklearn.metrics import ConfusionMatrixDisplay
# TODO: Remove when https://github.com/numpy/numpy/issues/14397 is resolved
pytestmark = pytest.mark.filterwarnings(
"ignore:In future, it will be an error for 'np.bool_':DeprecationWarning:"
"matplotlib.*"
)
@pytest.fixture(scope="module")
def n_classes():
return 5
@pytest.fixture(scope="module")
def data(n_classes):
X, y = make_classification(
n_samples=100, n_informative=5, n_classes=n_classes, random_state=0
)
return X, y
@pytest.fixture(scope="module")
def fitted_clf(data):
return SVC(kernel="linear", C=0.01).fit(*data)
@pytest.fixture(scope="module")
def y_pred(data, fitted_clf):
X, _ = data
return fitted_clf.predict(X)
@pytest.mark.filterwarnings("ignore: Function plot_confusion_matrix is deprecated")
def test_error_on_regressor(pyplot, data):
X, y = data
est = SVR().fit(X, y)
msg = "plot_confusion_matrix only supports classifiers"
with pytest.raises(ValueError, match=msg):
plot_confusion_matrix(est, X, y)
@pytest.mark.filterwarnings("ignore: Function plot_confusion_matrix is deprecated")
def test_error_on_invalid_option(pyplot, fitted_clf, data):
X, y = data
msg = r"normalize must be one of \{'true', 'pred', 'all', " r"None\}"
with pytest.raises(ValueError, match=msg):
plot_confusion_matrix(fitted_clf, X, y, normalize="invalid")
@pytest.mark.filterwarnings("ignore: Function plot_confusion_matrix is deprecated")
@pytest.mark.parametrize("with_labels", [True, False])
@pytest.mark.parametrize("with_display_labels", [True, False])
def test_plot_confusion_matrix_custom_labels(
pyplot, data, y_pred, fitted_clf, n_classes, with_labels, with_display_labels
):
X, y = data
ax = pyplot.gca()
labels = [2, 1, 0, 3, 4] if with_labels else None
display_labels = ["b", "d", "a", "e", "f"] if with_display_labels else None
cm = confusion_matrix(y, y_pred, labels=labels)
disp = plot_confusion_matrix(
fitted_clf, X, y, ax=ax, display_labels=display_labels, labels=labels
)
assert_allclose(disp.confusion_matrix, cm)
if with_display_labels:
expected_display_labels = display_labels
elif with_labels:
expected_display_labels = labels
else:
expected_display_labels = list(range(n_classes))
expected_display_labels_str = [str(name) for name in expected_display_labels]
x_ticks = [tick.get_text() for tick in disp.ax_.get_xticklabels()]
y_ticks = [tick.get_text() for tick in disp.ax_.get_yticklabels()]
assert_array_equal(disp.display_labels, expected_display_labels)
assert_array_equal(x_ticks, expected_display_labels_str)
assert_array_equal(y_ticks, expected_display_labels_str)
@pytest.mark.filterwarnings("ignore: Function plot_confusion_matrix is deprecated")
@pytest.mark.parametrize("normalize", ["true", "pred", "all", None])
@pytest.mark.parametrize("include_values", [True, False])
def test_plot_confusion_matrix(
pyplot, data, y_pred, n_classes, fitted_clf, normalize, include_values
):
X, y = data
ax = pyplot.gca()
cmap = "plasma"
cm = confusion_matrix(y, y_pred)
disp = plot_confusion_matrix(
fitted_clf,
X,
y,
normalize=normalize,
cmap=cmap,
ax=ax,
include_values=include_values,
)
assert disp.ax_ == ax
if normalize == "true":
cm = cm / cm.sum(axis=1, keepdims=True)
elif normalize == "pred":
cm = cm / cm.sum(axis=0, keepdims=True)
elif normalize == "all":
cm = cm / cm.sum()
assert_allclose(disp.confusion_matrix, cm)
import matplotlib as mpl
assert isinstance(disp.im_, mpl.image.AxesImage)
assert disp.im_.get_cmap().name == cmap
assert isinstance(disp.ax_, pyplot.Axes)
assert isinstance(disp.figure_, pyplot.Figure)
assert disp.ax_.get_ylabel() == "True label"
assert disp.ax_.get_xlabel() == "Predicted label"
x_ticks = [tick.get_text() for tick in disp.ax_.get_xticklabels()]
y_ticks = [tick.get_text() for tick in disp.ax_.get_yticklabels()]
expected_display_labels = list(range(n_classes))
expected_display_labels_str = [str(name) for name in expected_display_labels]
assert_array_equal(disp.display_labels, expected_display_labels)
assert_array_equal(x_ticks, expected_display_labels_str)
assert_array_equal(y_ticks, expected_display_labels_str)
image_data = disp.im_.get_array().data
assert_allclose(image_data, cm)
if include_values:
assert disp.text_.shape == (n_classes, n_classes)
fmt = ".2g"
expected_text = np.array([format(v, fmt) for v in cm.ravel(order="C")])
text_text = np.array([t.get_text() for t in disp.text_.ravel(order="C")])
assert_array_equal(expected_text, text_text)
else:
assert disp.text_ is None
@pytest.mark.filterwarnings("ignore: Function plot_confusion_matrix is deprecated")
def test_confusion_matrix_display(pyplot, data, fitted_clf, y_pred, n_classes):
X, y = data
cm = confusion_matrix(y, y_pred)
disp = plot_confusion_matrix(
fitted_clf,
X,
y,
normalize=None,
include_values=True,
cmap="viridis",
xticks_rotation=45.0,
)
assert_allclose(disp.confusion_matrix, cm)
assert disp.text_.shape == (n_classes, n_classes)
rotations = [tick.get_rotation() for tick in disp.ax_.get_xticklabels()]
assert_allclose(rotations, 45.0)
image_data = disp.im_.get_array().data
assert_allclose(image_data, cm)
disp.plot(cmap="plasma")
assert disp.im_.get_cmap().name == "plasma"
disp.plot(include_values=False)
assert disp.text_ is None
disp.plot(xticks_rotation=90.0)
rotations = [tick.get_rotation() for tick in disp.ax_.get_xticklabels()]
assert_allclose(rotations, 90.0)
disp.plot(values_format="e")
expected_text = np.array([format(v, "e") for v in cm.ravel(order="C")])
text_text = np.array([t.get_text() for t in disp.text_.ravel(order="C")])
assert_array_equal(expected_text, text_text)
def test_confusion_matrix_contrast(pyplot):
# make sure text color is appropriate depending on background
cm = np.eye(2) / 2
disp = ConfusionMatrixDisplay(cm, display_labels=[0, 1])
disp.plot(cmap=pyplot.cm.gray)
# diagonal text is black
assert_allclose(disp.text_[0, 0].get_color(), [0.0, 0.0, 0.0, 1.0])
assert_allclose(disp.text_[1, 1].get_color(), [0.0, 0.0, 0.0, 1.0])
# off-diagonal text is white
assert_allclose(disp.text_[0, 1].get_color(), [1.0, 1.0, 1.0, 1.0])
assert_allclose(disp.text_[1, 0].get_color(), [1.0, 1.0, 1.0, 1.0])
disp.plot(cmap=pyplot.cm.gray_r)
# diagonal text is white
assert_allclose(disp.text_[0, 1].get_color(), [0.0, 0.0, 0.0, 1.0])
assert_allclose(disp.text_[1, 0].get_color(), [0.0, 0.0, 0.0, 1.0])
# off-diagonal text is black
assert_allclose(disp.text_[0, 0].get_color(), [1.0, 1.0, 1.0, 1.0])
assert_allclose(disp.text_[1, 1].get_color(), [1.0, 1.0, 1.0, 1.0])
# Regression test for #15920
cm = np.array([[19, 34], [32, 58]])
disp = ConfusionMatrixDisplay(cm, display_labels=[0, 1])
disp.plot(cmap=pyplot.cm.Blues)
min_color = pyplot.cm.Blues(0)
max_color = pyplot.cm.Blues(255)
assert_allclose(disp.text_[0, 0].get_color(), max_color)
assert_allclose(disp.text_[0, 1].get_color(), max_color)
assert_allclose(disp.text_[1, 0].get_color(), max_color)
assert_allclose(disp.text_[1, 1].get_color(), min_color)
@pytest.mark.filterwarnings("ignore: Function plot_confusion_matrix is deprecated")
@pytest.mark.parametrize(
"clf",
[
LogisticRegression(),
make_pipeline(StandardScaler(), LogisticRegression()),
make_pipeline(
make_column_transformer((StandardScaler(), [0, 1])), LogisticRegression()
),
],
)
def test_confusion_matrix_pipeline(pyplot, clf, data, n_classes):
X, y = data
with pytest.raises(NotFittedError):
plot_confusion_matrix(clf, X, y)
clf.fit(X, y)
y_pred = clf.predict(X)
disp = plot_confusion_matrix(clf, X, y)
cm = confusion_matrix(y, y_pred)
assert_allclose(disp.confusion_matrix, cm)
assert disp.text_.shape == (n_classes, n_classes)
@pytest.mark.filterwarnings("ignore: Function plot_confusion_matrix is deprecated")
@pytest.mark.parametrize("colorbar", [True, False])
def test_plot_confusion_matrix_colorbar(pyplot, data, fitted_clf, colorbar):
X, y = data
def _check_colorbar(disp, has_colorbar):
if has_colorbar:
assert disp.im_.colorbar is not None
assert disp.im_.colorbar.__class__.__name__ == "Colorbar"
else:
assert disp.im_.colorbar is None
disp = plot_confusion_matrix(fitted_clf, X, y, colorbar=colorbar)
_check_colorbar(disp, colorbar)
# attempt a plot with the opposite effect of colorbar
disp.plot(colorbar=not colorbar)
_check_colorbar(disp, not colorbar)
@pytest.mark.filterwarnings("ignore: Function plot_confusion_matrix is deprecated")
@pytest.mark.parametrize("values_format", ["e", "n"])
def test_confusion_matrix_text_format(
pyplot, data, y_pred, n_classes, fitted_clf, values_format
):
# Make sure plot text is formatted with 'values_format'.
X, y = data
cm = confusion_matrix(y, y_pred)
disp = plot_confusion_matrix(
fitted_clf, X, y, include_values=True, values_format=values_format
)
assert disp.text_.shape == (n_classes, n_classes)
expected_text = np.array([format(v, values_format) for v in cm.ravel()])
text_text = np.array([t.get_text() for t in disp.text_.ravel()])
assert_array_equal(expected_text, text_text)
def test_confusion_matrix_standard_format(pyplot):
cm = np.array([[10000000, 0], [123456, 12345678]])
plotted_text = ConfusionMatrixDisplay(cm, display_labels=[False, True]).plot().text_
# Values should be shown as whole numbers 'd',
# except the first number which should be shown as 1e+07 (longer length)
# and the last number will be shown as 1.2e+07 (longer length)
test = [t.get_text() for t in plotted_text.ravel()]
assert test == ["1e+07", "0", "123456", "1.2e+07"]
cm = np.array([[0.1, 10], [100, 0.525]])
plotted_text = ConfusionMatrixDisplay(cm, display_labels=[False, True]).plot().text_
# Values should now formatted as '.2g', since there's a float in
# Values are have two dec places max, (e.g 100 becomes 1e+02)
test = [t.get_text() for t in plotted_text.ravel()]
assert test == ["0.1", "10", "1e+02", "0.53"]
@pytest.mark.parametrize(
"display_labels, expected_labels",
[
(None, ["0", "1"]),
(["cat", "dog"], ["cat", "dog"]),
],
)
def test_default_labels(pyplot, display_labels, expected_labels):
cm = np.array([[10, 0], [12, 120]])
disp = ConfusionMatrixDisplay(cm, display_labels=display_labels).plot()
x_ticks = [tick.get_text() for tick in disp.ax_.get_xticklabels()]
y_ticks = [tick.get_text() for tick in disp.ax_.get_yticklabels()]
assert_array_equal(x_ticks, expected_labels)
assert_array_equal(y_ticks, expected_labels)
@pytest.mark.filterwarnings("ignore: Function plot_confusion_matrix is deprecated")
def test_error_on_a_dataset_with_unseen_labels(pyplot, fitted_clf, data, n_classes):
"""Check that when labels=None, the unique values in `y_pred` and `y_true`
will be used.
Non-regression test for:
https://github.com/scikit-learn/scikit-learn/pull/18405
"""
X, y = data
# create unseen labels in `y_true` not seen during fitting and not present
# in 'fitted_clf.classes_'
y = y + 1
disp = plot_confusion_matrix(fitted_clf, X, y)
display_labels = [tick.get_text() for tick in disp.ax_.get_xticklabels()]
expected_labels = [str(i) for i in range(n_classes + 1)]
assert_array_equal(expected_labels, display_labels)
def test_plot_confusion_matrix_deprecation_warning(pyplot, fitted_clf, data):
with pytest.warns(FutureWarning):
plot_confusion_matrix(fitted_clf, *data)

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import pytest
from sklearn.base import ClassifierMixin
from sklearn.base import clone
from sklearn.compose import make_column_transformer
from sklearn.datasets import load_iris
from sklearn.exceptions import NotFittedError
from sklearn.linear_model import LogisticRegression
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.tree import DecisionTreeClassifier
from sklearn.metrics import plot_det_curve
from sklearn.metrics import plot_roc_curve
pytestmark = pytest.mark.filterwarnings(
"ignore:Function plot_roc_curve is deprecated",
)
@pytest.fixture(scope="module")
def data():
return load_iris(return_X_y=True)
@pytest.fixture(scope="module")
def data_binary(data):
X, y = data
return X[y < 2], y[y < 2]
@pytest.mark.filterwarnings("ignore: Function plot_det_curve is deprecated")
@pytest.mark.parametrize("plot_func", [plot_det_curve, plot_roc_curve])
def test_plot_curve_error_non_binary(pyplot, data, plot_func):
X, y = data
clf = DecisionTreeClassifier()
clf.fit(X, y)
msg = (
"Expected 'estimator' to be a binary classifier, but got DecisionTreeClassifier"
)
with pytest.raises(ValueError, match=msg):
plot_func(clf, X, y)
@pytest.mark.filterwarnings("ignore: Function plot_det_curve is deprecated")
@pytest.mark.parametrize(
"response_method, msg",
[
(
"predict_proba",
"response method predict_proba is not defined in MyClassifier",
),
(
"decision_function",
"response method decision_function is not defined in MyClassifier",
),
(
"auto",
"response method decision_function or predict_proba is not "
"defined in MyClassifier",
),
(
"bad_method",
"response_method must be 'predict_proba', 'decision_function' or 'auto'",
),
],
)
@pytest.mark.parametrize("plot_func", [plot_det_curve, plot_roc_curve])
def test_plot_curve_error_no_response(
pyplot,
data_binary,
response_method,
msg,
plot_func,
):
X, y = data_binary
class MyClassifier(ClassifierMixin):
def fit(self, X, y):
self.classes_ = [0, 1]
return self
clf = MyClassifier().fit(X, y)
with pytest.raises(ValueError, match=msg):
plot_func(clf, X, y, response_method=response_method)
@pytest.mark.filterwarnings("ignore: Function plot_det_curve is deprecated")
@pytest.mark.parametrize("plot_func", [plot_det_curve, plot_roc_curve])
def test_plot_curve_estimator_name_multiple_calls(pyplot, data_binary, plot_func):
# non-regression test checking that the `name` used when calling
# `plot_func` is used as well when calling `disp.plot()`
X, y = data_binary
clf_name = "my hand-crafted name"
clf = LogisticRegression().fit(X, y)
disp = plot_func(clf, X, y, name=clf_name)
assert disp.estimator_name == clf_name
pyplot.close("all")
disp.plot()
assert clf_name in disp.line_.get_label()
pyplot.close("all")
clf_name = "another_name"
disp.plot(name=clf_name)
assert clf_name in disp.line_.get_label()
@pytest.mark.filterwarnings("ignore: Function plot_det_curve is deprecated")
@pytest.mark.parametrize(
"clf",
[
LogisticRegression(),
make_pipeline(StandardScaler(), LogisticRegression()),
make_pipeline(
make_column_transformer((StandardScaler(), [0, 1])), LogisticRegression()
),
],
)
@pytest.mark.parametrize("plot_func", [plot_det_curve, plot_roc_curve])
def test_plot_det_curve_not_fitted_errors(pyplot, data_binary, clf, plot_func):
X, y = data_binary
# clone since we parametrize the test and the classifier will be fitted
# when testing the second and subsequent plotting function
model = clone(clf)
with pytest.raises(NotFittedError):
plot_func(model, X, y)
model.fit(X, y)
disp = plot_func(model, X, y)
assert model.__class__.__name__ in disp.line_.get_label()
assert disp.estimator_name == model.__class__.__name__

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# TODO: remove this file when plot_det_curve will be deprecated in 1.2
import pytest
import numpy as np
from numpy.testing import assert_allclose
from sklearn.datasets import load_iris
from sklearn.linear_model import LogisticRegression
from sklearn.metrics import det_curve
from sklearn.metrics import plot_det_curve
@pytest.fixture(scope="module")
def data():
return load_iris(return_X_y=True)
@pytest.fixture(scope="module")
def data_binary(data):
X, y = data
return X[y < 2], y[y < 2]
@pytest.mark.filterwarnings("ignore: Function plot_det_curve is deprecated")
@pytest.mark.parametrize("response_method", ["predict_proba", "decision_function"])
@pytest.mark.parametrize("with_sample_weight", [True, False])
@pytest.mark.parametrize("with_strings", [True, False])
def test_plot_det_curve(
pyplot, response_method, data_binary, with_sample_weight, with_strings
):
X, y = data_binary
pos_label = None
if with_strings:
y = np.array(["c", "b"])[y]
pos_label = "c"
if with_sample_weight:
rng = np.random.RandomState(42)
sample_weight = rng.randint(1, 4, size=(X.shape[0]))
else:
sample_weight = None
lr = LogisticRegression()
lr.fit(X, y)
viz = plot_det_curve(
lr,
X,
y,
alpha=0.8,
sample_weight=sample_weight,
)
y_pred = getattr(lr, response_method)(X)
if y_pred.ndim == 2:
y_pred = y_pred[:, 1]
fpr, fnr, _ = det_curve(
y,
y_pred,
sample_weight=sample_weight,
pos_label=pos_label,
)
assert_allclose(viz.fpr, fpr)
assert_allclose(viz.fnr, fnr)
assert viz.estimator_name == "LogisticRegression"
# cannot fail thanks to pyplot fixture
import matplotlib as mpl # noqal
assert isinstance(viz.line_, mpl.lines.Line2D)
assert viz.line_.get_alpha() == 0.8
assert isinstance(viz.ax_, mpl.axes.Axes)
assert isinstance(viz.figure_, mpl.figure.Figure)
assert viz.line_.get_label() == "LogisticRegression"
expected_pos_label = 1 if pos_label is None else pos_label
expected_ylabel = f"False Negative Rate (Positive label: {expected_pos_label})"
expected_xlabel = f"False Positive Rate (Positive label: {expected_pos_label})"
assert viz.ax_.get_ylabel() == expected_ylabel
assert viz.ax_.get_xlabel() == expected_xlabel

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import pytest
import numpy as np
from numpy.testing import assert_allclose
from sklearn.base import BaseEstimator, ClassifierMixin
from sklearn.metrics import plot_precision_recall_curve
from sklearn.metrics import average_precision_score
from sklearn.metrics import precision_recall_curve
from sklearn.datasets import make_classification
from sklearn.datasets import load_breast_cancer
from sklearn.tree import DecisionTreeClassifier, DecisionTreeRegressor
from sklearn.linear_model import LogisticRegression
from sklearn.model_selection import train_test_split
from sklearn.exceptions import NotFittedError
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.utils import shuffle
from sklearn.compose import make_column_transformer
pytestmark = pytest.mark.filterwarnings(
# TODO: Remove when https://github.com/numpy/numpy/issues/14397 is resolved
"ignore:In future, it will be an error for 'np.bool_':DeprecationWarning:"
"matplotlib.*",
# TODO: Remove in 1.2 (as well as all the tests below)
"ignore:Function plot_precision_recall_curve is deprecated",
)
def test_errors(pyplot):
X, y_multiclass = make_classification(
n_classes=3, n_samples=50, n_informative=3, random_state=0
)
y_binary = y_multiclass == 0
# Unfitted classifier
binary_clf = DecisionTreeClassifier()
with pytest.raises(NotFittedError):
plot_precision_recall_curve(binary_clf, X, y_binary)
binary_clf.fit(X, y_binary)
multi_clf = DecisionTreeClassifier().fit(X, y_multiclass)
# Fitted multiclass classifier with binary data
msg = (
"Expected 'estimator' to be a binary classifier, but got DecisionTreeClassifier"
)
with pytest.raises(ValueError, match=msg):
plot_precision_recall_curve(multi_clf, X, y_binary)
reg = DecisionTreeRegressor().fit(X, y_multiclass)
msg = (
"Expected 'estimator' to be a binary classifier, but got DecisionTreeRegressor"
)
with pytest.raises(ValueError, match=msg):
plot_precision_recall_curve(reg, X, y_binary)
@pytest.mark.parametrize(
"response_method, msg",
[
(
"predict_proba",
"response method predict_proba is not defined in MyClassifier",
),
(
"decision_function",
"response method decision_function is not defined in MyClassifier",
),
(
"auto",
"response method decision_function or predict_proba is not "
"defined in MyClassifier",
),
(
"bad_method",
"response_method must be 'predict_proba', 'decision_function' or 'auto'",
),
],
)
def test_error_bad_response(pyplot, response_method, msg):
X, y = make_classification(n_classes=2, n_samples=50, random_state=0)
class MyClassifier(ClassifierMixin, BaseEstimator):
def fit(self, X, y):
self.fitted_ = True
self.classes_ = [0, 1]
return self
clf = MyClassifier().fit(X, y)
with pytest.raises(ValueError, match=msg):
plot_precision_recall_curve(clf, X, y, response_method=response_method)
@pytest.mark.parametrize("response_method", ["predict_proba", "decision_function"])
@pytest.mark.parametrize("with_sample_weight", [True, False])
def test_plot_precision_recall(pyplot, response_method, with_sample_weight):
X, y = make_classification(n_classes=2, n_samples=50, random_state=0)
lr = LogisticRegression().fit(X, y)
if with_sample_weight:
rng = np.random.RandomState(42)
sample_weight = rng.randint(0, 4, size=X.shape[0])
else:
sample_weight = None
disp = plot_precision_recall_curve(
lr,
X,
y,
alpha=0.8,
response_method=response_method,
sample_weight=sample_weight,
)
y_score = getattr(lr, response_method)(X)
if response_method == "predict_proba":
y_score = y_score[:, 1]
prec, recall, _ = precision_recall_curve(y, y_score, sample_weight=sample_weight)
avg_prec = average_precision_score(y, y_score, sample_weight=sample_weight)
assert_allclose(disp.precision, prec)
assert_allclose(disp.recall, recall)
assert disp.average_precision == pytest.approx(avg_prec)
assert disp.estimator_name == "LogisticRegression"
# cannot fail thanks to pyplot fixture
import matplotlib as mpl # noqa
assert isinstance(disp.line_, mpl.lines.Line2D)
assert disp.line_.get_alpha() == 0.8
assert isinstance(disp.ax_, mpl.axes.Axes)
assert isinstance(disp.figure_, mpl.figure.Figure)
expected_label = "LogisticRegression (AP = {:0.2f})".format(avg_prec)
assert disp.line_.get_label() == expected_label
assert disp.ax_.get_xlabel() == "Recall (Positive label: 1)"
assert disp.ax_.get_ylabel() == "Precision (Positive label: 1)"
# draw again with another label
disp.plot(name="MySpecialEstimator")
expected_label = "MySpecialEstimator (AP = {:0.2f})".format(avg_prec)
assert disp.line_.get_label() == expected_label
@pytest.mark.parametrize(
"clf",
[
make_pipeline(StandardScaler(), LogisticRegression()),
make_pipeline(
make_column_transformer((StandardScaler(), [0, 1])), LogisticRegression()
),
],
)
def test_precision_recall_curve_pipeline(pyplot, clf):
X, y = make_classification(n_classes=2, n_samples=50, random_state=0)
with pytest.raises(NotFittedError):
plot_precision_recall_curve(clf, X, y)
clf.fit(X, y)
disp = plot_precision_recall_curve(clf, X, y)
assert disp.estimator_name == clf.__class__.__name__
def test_precision_recall_curve_string_labels(pyplot):
# regression test #15738
cancer = load_breast_cancer()
X = cancer.data
y = cancer.target_names[cancer.target]
lr = make_pipeline(StandardScaler(), LogisticRegression())
lr.fit(X, y)
for klass in cancer.target_names:
assert klass in lr.classes_
disp = plot_precision_recall_curve(lr, X, y)
y_pred = lr.predict_proba(X)[:, 1]
avg_prec = average_precision_score(y, y_pred, pos_label=lr.classes_[1])
assert disp.average_precision == pytest.approx(avg_prec)
assert disp.estimator_name == lr.__class__.__name__
def test_plot_precision_recall_curve_estimator_name_multiple_calls(pyplot):
# non-regression test checking that the `name` used when calling
# `plot_precision_recall_curve` is used as well when calling `disp.plot()`
X, y = make_classification(n_classes=2, n_samples=50, random_state=0)
clf_name = "my hand-crafted name"
clf = LogisticRegression().fit(X, y)
disp = plot_precision_recall_curve(clf, X, y, name=clf_name)
assert disp.estimator_name == clf_name
pyplot.close("all")
disp.plot()
assert clf_name in disp.line_.get_label()
pyplot.close("all")
clf_name = "another_name"
disp.plot(name=clf_name)
assert clf_name in disp.line_.get_label()
@pytest.mark.parametrize("response_method", ["predict_proba", "decision_function"])
def test_plot_precision_recall_pos_label(pyplot, response_method):
# check that we can provide the positive label and display the proper
# statistics
X, y = load_breast_cancer(return_X_y=True)
# create an highly imbalanced version of the breast cancer dataset
idx_positive = np.flatnonzero(y == 1)
idx_negative = np.flatnonzero(y == 0)
idx_selected = np.hstack([idx_negative, idx_positive[:25]])
X, y = X[idx_selected], y[idx_selected]
X, y = shuffle(X, y, random_state=42)
# only use 2 features to make the problem even harder
X = X[:, :2]
y = np.array(["cancer" if c == 1 else "not cancer" for c in y], dtype=object)
X_train, X_test, y_train, y_test = train_test_split(
X,
y,
stratify=y,
random_state=0,
)
classifier = LogisticRegression()
classifier.fit(X_train, y_train)
# sanity check to be sure the positive class is classes_[0] and that we
# are betrayed by the class imbalance
assert classifier.classes_.tolist() == ["cancer", "not cancer"]
disp = plot_precision_recall_curve(
classifier, X_test, y_test, pos_label="cancer", response_method=response_method
)
# we should obtain the statistics of the "cancer" class
avg_prec_limit = 0.65
assert disp.average_precision < avg_prec_limit
assert -np.trapz(disp.precision, disp.recall) < avg_prec_limit
# otherwise we should obtain the statistics of the "not cancer" class
disp = plot_precision_recall_curve(
classifier,
X_test,
y_test,
response_method=response_method,
)
avg_prec_limit = 0.95
assert disp.average_precision > avg_prec_limit
assert -np.trapz(disp.precision, disp.recall) > avg_prec_limit

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import pytest
import numpy as np
from numpy.testing import assert_allclose
from sklearn.metrics import plot_roc_curve
from sklearn.metrics import roc_curve
from sklearn.metrics import auc
from sklearn.datasets import load_iris
from sklearn.datasets import load_breast_cancer
from sklearn.linear_model import LogisticRegression
from sklearn.model_selection import train_test_split
from sklearn.exceptions import NotFittedError
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.utils import shuffle
from sklearn.compose import make_column_transformer
# TODO: Remove when https://github.com/numpy/numpy/issues/14397 is resolved
pytestmark = pytest.mark.filterwarnings(
"ignore:In future, it will be an error for 'np.bool_':DeprecationWarning:"
"matplotlib.*",
"ignore:Function plot_roc_curve is deprecated",
)
@pytest.fixture(scope="module")
def data():
return load_iris(return_X_y=True)
@pytest.fixture(scope="module")
def data_binary(data):
X, y = data
return X[y < 2], y[y < 2]
@pytest.mark.parametrize("response_method", ["predict_proba", "decision_function"])
@pytest.mark.parametrize("with_sample_weight", [True, False])
@pytest.mark.parametrize("drop_intermediate", [True, False])
@pytest.mark.parametrize("with_strings", [True, False])
def test_plot_roc_curve(
pyplot,
response_method,
data_binary,
with_sample_weight,
drop_intermediate,
with_strings,
):
X, y = data_binary
pos_label = None
if with_strings:
y = np.array(["c", "b"])[y]
pos_label = "c"
if with_sample_weight:
rng = np.random.RandomState(42)
sample_weight = rng.randint(1, 4, size=(X.shape[0]))
else:
sample_weight = None
lr = LogisticRegression()
lr.fit(X, y)
viz = plot_roc_curve(
lr,
X,
y,
alpha=0.8,
sample_weight=sample_weight,
drop_intermediate=drop_intermediate,
)
y_pred = getattr(lr, response_method)(X)
if y_pred.ndim == 2:
y_pred = y_pred[:, 1]
fpr, tpr, _ = roc_curve(
y,
y_pred,
sample_weight=sample_weight,
drop_intermediate=drop_intermediate,
pos_label=pos_label,
)
assert_allclose(viz.roc_auc, auc(fpr, tpr))
assert_allclose(viz.fpr, fpr)
assert_allclose(viz.tpr, tpr)
assert viz.estimator_name == "LogisticRegression"
# cannot fail thanks to pyplot fixture
import matplotlib as mpl # noqal
assert isinstance(viz.line_, mpl.lines.Line2D)
assert viz.line_.get_alpha() == 0.8
assert isinstance(viz.ax_, mpl.axes.Axes)
assert isinstance(viz.figure_, mpl.figure.Figure)
expected_label = "LogisticRegression (AUC = {:0.2f})".format(viz.roc_auc)
assert viz.line_.get_label() == expected_label
expected_pos_label = 1 if pos_label is None else pos_label
expected_ylabel = f"True Positive Rate (Positive label: {expected_pos_label})"
expected_xlabel = f"False Positive Rate (Positive label: {expected_pos_label})"
assert viz.ax_.get_ylabel() == expected_ylabel
assert viz.ax_.get_xlabel() == expected_xlabel
@pytest.mark.parametrize(
"clf",
[
LogisticRegression(),
make_pipeline(StandardScaler(), LogisticRegression()),
make_pipeline(
make_column_transformer((StandardScaler(), [0, 1])), LogisticRegression()
),
],
)
def test_roc_curve_not_fitted_errors(pyplot, data_binary, clf):
X, y = data_binary
with pytest.raises(NotFittedError):
plot_roc_curve(clf, X, y)
clf.fit(X, y)
disp = plot_roc_curve(clf, X, y)
assert clf.__class__.__name__ in disp.line_.get_label()
assert disp.estimator_name == clf.__class__.__name__
@pytest.mark.parametrize("response_method", ["predict_proba", "decision_function"])
def test_plot_roc_curve_pos_label(pyplot, response_method):
# check that we can provide the positive label and display the proper
# statistics
X, y = load_breast_cancer(return_X_y=True)
# create an highly imbalanced
idx_positive = np.flatnonzero(y == 1)
idx_negative = np.flatnonzero(y == 0)
idx_selected = np.hstack([idx_negative, idx_positive[:25]])
X, y = X[idx_selected], y[idx_selected]
X, y = shuffle(X, y, random_state=42)
# only use 2 features to make the problem even harder
X = X[:, :2]
y = np.array(["cancer" if c == 1 else "not cancer" for c in y], dtype=object)
X_train, X_test, y_train, y_test = train_test_split(
X,
y,
stratify=y,
random_state=0,
)
classifier = LogisticRegression()
classifier.fit(X_train, y_train)
# sanity check to be sure the positive class is classes_[0] and that we
# are betrayed by the class imbalance
assert classifier.classes_.tolist() == ["cancer", "not cancer"]
disp = plot_roc_curve(
classifier, X_test, y_test, pos_label="cancer", response_method=response_method
)
roc_auc_limit = 0.95679
assert disp.roc_auc == pytest.approx(roc_auc_limit)
assert np.trapz(disp.tpr, disp.fpr) == pytest.approx(roc_auc_limit)
disp = plot_roc_curve(
classifier,
X_test,
y_test,
response_method=response_method,
)
assert disp.roc_auc == pytest.approx(roc_auc_limit)
assert np.trapz(disp.tpr, disp.fpr) == pytest.approx(roc_auc_limit)

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@@ -0,0 +1,304 @@
import numpy as np
import pytest
from sklearn.compose import make_column_transformer
from sklearn.datasets import load_breast_cancer, make_classification
from sklearn.exceptions import NotFittedError
from sklearn.linear_model import LogisticRegression
from sklearn.metrics import average_precision_score, precision_recall_curve
from sklearn.model_selection import train_test_split
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.svm import SVC, SVR
from sklearn.utils import shuffle
from sklearn.metrics import PrecisionRecallDisplay, plot_precision_recall_curve
# TODO: Remove when https://github.com/numpy/numpy/issues/14397 is resolved
pytestmark = pytest.mark.filterwarnings(
"ignore:In future, it will be an error for 'np.bool_':DeprecationWarning:"
"matplotlib.*"
)
def test_precision_recall_display_validation(pyplot):
"""Check that we raise the proper error when validating parameters."""
X, y = make_classification(
n_samples=100, n_informative=5, n_classes=5, random_state=0
)
with pytest.raises(NotFittedError):
PrecisionRecallDisplay.from_estimator(SVC(), X, y)
regressor = SVR().fit(X, y)
y_pred_regressor = regressor.predict(X)
classifier = SVC(probability=True).fit(X, y)
y_pred_classifier = classifier.predict_proba(X)[:, -1]
err_msg = "PrecisionRecallDisplay.from_estimator only supports classifiers"
with pytest.raises(ValueError, match=err_msg):
PrecisionRecallDisplay.from_estimator(regressor, X, y)
err_msg = "Expected 'estimator' to be a binary classifier, but got SVC"
with pytest.raises(ValueError, match=err_msg):
PrecisionRecallDisplay.from_estimator(classifier, X, y)
err_msg = "{} format is not supported"
with pytest.raises(ValueError, match=err_msg.format("continuous")):
# Force `y_true` to be seen as a regression problem
PrecisionRecallDisplay.from_predictions(y + 0.5, y_pred_classifier, pos_label=1)
with pytest.raises(ValueError, match=err_msg.format("multiclass")):
PrecisionRecallDisplay.from_predictions(y, y_pred_regressor, pos_label=1)
err_msg = "Found input variables with inconsistent numbers of samples"
with pytest.raises(ValueError, match=err_msg):
PrecisionRecallDisplay.from_predictions(y, y_pred_classifier[::2])
X, y = make_classification(n_classes=2, n_samples=50, random_state=0)
y += 10
classifier.fit(X, y)
y_pred_classifier = classifier.predict_proba(X)[:, -1]
err_msg = r"y_true takes value in {10, 11} and pos_label is not specified"
with pytest.raises(ValueError, match=err_msg):
PrecisionRecallDisplay.from_predictions(y, y_pred_classifier)
# FIXME: Remove in 1.2
def test_plot_precision_recall_curve_deprecation(pyplot):
"""Check that we raise a FutureWarning when calling
`plot_precision_recall_curve`."""
X, y = make_classification(random_state=0)
clf = LogisticRegression().fit(X, y)
deprecation_warning = "Function plot_precision_recall_curve is deprecated"
with pytest.warns(FutureWarning, match=deprecation_warning):
plot_precision_recall_curve(clf, X, y)
@pytest.mark.parametrize("constructor_name", ["from_estimator", "from_predictions"])
@pytest.mark.parametrize("response_method", ["predict_proba", "decision_function"])
def test_precision_recall_display_plotting(pyplot, constructor_name, response_method):
"""Check the overall plotting rendering."""
X, y = make_classification(n_classes=2, n_samples=50, random_state=0)
pos_label = 1
classifier = LogisticRegression().fit(X, y)
classifier.fit(X, y)
y_pred = getattr(classifier, response_method)(X)
y_pred = y_pred if y_pred.ndim == 1 else y_pred[:, pos_label]
# safe guard for the binary if/else construction
assert constructor_name in ("from_estimator", "from_predictions")
if constructor_name == "from_estimator":
display = PrecisionRecallDisplay.from_estimator(
classifier, X, y, response_method=response_method
)
else:
display = PrecisionRecallDisplay.from_predictions(
y, y_pred, pos_label=pos_label
)
precision, recall, _ = precision_recall_curve(y, y_pred, pos_label=pos_label)
average_precision = average_precision_score(y, y_pred, pos_label=pos_label)
np.testing.assert_allclose(display.precision, precision)
np.testing.assert_allclose(display.recall, recall)
assert display.average_precision == pytest.approx(average_precision)
import matplotlib as mpl
assert isinstance(display.line_, mpl.lines.Line2D)
assert isinstance(display.ax_, mpl.axes.Axes)
assert isinstance(display.figure_, mpl.figure.Figure)
assert display.ax_.get_xlabel() == "Recall (Positive label: 1)"
assert display.ax_.get_ylabel() == "Precision (Positive label: 1)"
# plotting passing some new parameters
display.plot(alpha=0.8, name="MySpecialEstimator")
expected_label = f"MySpecialEstimator (AP = {average_precision:0.2f})"
assert display.line_.get_label() == expected_label
assert display.line_.get_alpha() == pytest.approx(0.8)
@pytest.mark.parametrize(
"constructor_name, default_label",
[
("from_estimator", "LogisticRegression (AP = {:.2f})"),
("from_predictions", "Classifier (AP = {:.2f})"),
],
)
def test_precision_recall_display_name(pyplot, constructor_name, default_label):
"""Check the behaviour of the name parameters"""
X, y = make_classification(n_classes=2, n_samples=100, random_state=0)
pos_label = 1
classifier = LogisticRegression().fit(X, y)
classifier.fit(X, y)
y_pred = classifier.predict_proba(X)[:, pos_label]
# safe guard for the binary if/else construction
assert constructor_name in ("from_estimator", "from_predictions")
if constructor_name == "from_estimator":
display = PrecisionRecallDisplay.from_estimator(classifier, X, y)
else:
display = PrecisionRecallDisplay.from_predictions(
y, y_pred, pos_label=pos_label
)
average_precision = average_precision_score(y, y_pred, pos_label=pos_label)
# check that the default name is used
assert display.line_.get_label() == default_label.format(average_precision)
# check that the name can be set
display.plot(name="MySpecialEstimator")
assert (
display.line_.get_label()
== f"MySpecialEstimator (AP = {average_precision:.2f})"
)
@pytest.mark.parametrize(
"clf",
[
make_pipeline(StandardScaler(), LogisticRegression()),
make_pipeline(
make_column_transformer((StandardScaler(), [0, 1])), LogisticRegression()
),
],
)
def test_precision_recall_display_pipeline(pyplot, clf):
X, y = make_classification(n_classes=2, n_samples=50, random_state=0)
with pytest.raises(NotFittedError):
PrecisionRecallDisplay.from_estimator(clf, X, y)
clf.fit(X, y)
display = PrecisionRecallDisplay.from_estimator(clf, X, y)
assert display.estimator_name == clf.__class__.__name__
def test_precision_recall_display_string_labels(pyplot):
# regression test #15738
cancer = load_breast_cancer()
X, y = cancer.data, cancer.target_names[cancer.target]
lr = make_pipeline(StandardScaler(), LogisticRegression())
lr.fit(X, y)
for klass in cancer.target_names:
assert klass in lr.classes_
display = PrecisionRecallDisplay.from_estimator(lr, X, y)
y_pred = lr.predict_proba(X)[:, 1]
avg_prec = average_precision_score(y, y_pred, pos_label=lr.classes_[1])
assert display.average_precision == pytest.approx(avg_prec)
assert display.estimator_name == lr.__class__.__name__
err_msg = r"y_true takes value in {'benign', 'malignant'}"
with pytest.raises(ValueError, match=err_msg):
PrecisionRecallDisplay.from_predictions(y, y_pred)
display = PrecisionRecallDisplay.from_predictions(
y, y_pred, pos_label=lr.classes_[1]
)
assert display.average_precision == pytest.approx(avg_prec)
@pytest.mark.parametrize(
"average_precision, estimator_name, expected_label",
[
(0.9, None, "AP = 0.90"),
(None, "my_est", "my_est"),
(0.8, "my_est2", "my_est2 (AP = 0.80)"),
],
)
def test_default_labels(pyplot, average_precision, estimator_name, expected_label):
"""Check the default labels used in the display."""
precision = np.array([1, 0.5, 0])
recall = np.array([0, 0.5, 1])
display = PrecisionRecallDisplay(
precision,
recall,
average_precision=average_precision,
estimator_name=estimator_name,
)
display.plot()
assert display.line_.get_label() == expected_label
@pytest.mark.parametrize("constructor_name", ["from_estimator", "from_predictions"])
@pytest.mark.parametrize("response_method", ["predict_proba", "decision_function"])
def test_plot_precision_recall_pos_label(pyplot, constructor_name, response_method):
# check that we can provide the positive label and display the proper
# statistics
X, y = load_breast_cancer(return_X_y=True)
# create an highly imbalanced version of the breast cancer dataset
idx_positive = np.flatnonzero(y == 1)
idx_negative = np.flatnonzero(y == 0)
idx_selected = np.hstack([idx_negative, idx_positive[:25]])
X, y = X[idx_selected], y[idx_selected]
X, y = shuffle(X, y, random_state=42)
# only use 2 features to make the problem even harder
X = X[:, :2]
y = np.array(["cancer" if c == 1 else "not cancer" for c in y], dtype=object)
X_train, X_test, y_train, y_test = train_test_split(
X,
y,
stratify=y,
random_state=0,
)
classifier = LogisticRegression()
classifier.fit(X_train, y_train)
# sanity check to be sure the positive class is classes_[0] and that we
# are betrayed by the class imbalance
assert classifier.classes_.tolist() == ["cancer", "not cancer"]
y_pred = getattr(classifier, response_method)(X_test)
# we select the corresponding probability columns or reverse the decision
# function otherwise
y_pred_cancer = -1 * y_pred if y_pred.ndim == 1 else y_pred[:, 0]
y_pred_not_cancer = y_pred if y_pred.ndim == 1 else y_pred[:, 1]
if constructor_name == "from_estimator":
display = PrecisionRecallDisplay.from_estimator(
classifier,
X_test,
y_test,
pos_label="cancer",
response_method=response_method,
)
else:
display = PrecisionRecallDisplay.from_predictions(
y_test,
y_pred_cancer,
pos_label="cancer",
)
# we should obtain the statistics of the "cancer" class
avg_prec_limit = 0.65
assert display.average_precision < avg_prec_limit
assert -np.trapz(display.precision, display.recall) < avg_prec_limit
# otherwise we should obtain the statistics of the "not cancer" class
if constructor_name == "from_estimator":
display = PrecisionRecallDisplay.from_estimator(
classifier,
X_test,
y_test,
response_method=response_method,
pos_label="not cancer",
)
else:
display = PrecisionRecallDisplay.from_predictions(
y_test,
y_pred_not_cancer,
pos_label="not cancer",
)
avg_prec_limit = 0.95
assert display.average_precision > avg_prec_limit
assert -np.trapz(display.precision, display.recall) > avg_prec_limit

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import pytest
import numpy as np
from numpy.testing import assert_allclose
from sklearn.compose import make_column_transformer
from sklearn.datasets import load_iris
from sklearn.datasets import load_breast_cancer, make_classification
from sklearn.exceptions import NotFittedError
from sklearn.linear_model import LogisticRegression
from sklearn.metrics import roc_curve
from sklearn.metrics import auc
from sklearn.model_selection import train_test_split
from sklearn.pipeline import make_pipeline
from sklearn.preprocessing import StandardScaler
from sklearn.utils import shuffle
from sklearn.metrics import RocCurveDisplay, plot_roc_curve
@pytest.fixture(scope="module")
def data():
return load_iris(return_X_y=True)
@pytest.fixture(scope="module")
def data_binary(data):
X, y = data
return X[y < 2], y[y < 2]
@pytest.mark.parametrize("response_method", ["predict_proba", "decision_function"])
@pytest.mark.parametrize("with_sample_weight", [True, False])
@pytest.mark.parametrize("drop_intermediate", [True, False])
@pytest.mark.parametrize("with_strings", [True, False])
@pytest.mark.parametrize(
"constructor_name, default_name",
[
("from_estimator", "LogisticRegression"),
("from_predictions", "Classifier"),
],
)
def test_roc_curve_display_plotting(
pyplot,
response_method,
data_binary,
with_sample_weight,
drop_intermediate,
with_strings,
constructor_name,
default_name,
):
"""Check the overall plotting behaviour."""
X, y = data_binary
pos_label = None
if with_strings:
y = np.array(["c", "b"])[y]
pos_label = "c"
if with_sample_weight:
rng = np.random.RandomState(42)
sample_weight = rng.randint(1, 4, size=(X.shape[0]))
else:
sample_weight = None
lr = LogisticRegression()
lr.fit(X, y)
y_pred = getattr(lr, response_method)(X)
y_pred = y_pred if y_pred.ndim == 1 else y_pred[:, 1]
if constructor_name == "from_estimator":
display = RocCurveDisplay.from_estimator(
lr,
X,
y,
sample_weight=sample_weight,
drop_intermediate=drop_intermediate,
pos_label=pos_label,
alpha=0.8,
)
else:
display = RocCurveDisplay.from_predictions(
y,
y_pred,
sample_weight=sample_weight,
drop_intermediate=drop_intermediate,
pos_label=pos_label,
alpha=0.8,
)
fpr, tpr, _ = roc_curve(
y,
y_pred,
sample_weight=sample_weight,
drop_intermediate=drop_intermediate,
pos_label=pos_label,
)
assert_allclose(display.roc_auc, auc(fpr, tpr))
assert_allclose(display.fpr, fpr)
assert_allclose(display.tpr, tpr)
assert display.estimator_name == default_name
import matplotlib as mpl # noqal
assert isinstance(display.line_, mpl.lines.Line2D)
assert display.line_.get_alpha() == 0.8
assert isinstance(display.ax_, mpl.axes.Axes)
assert isinstance(display.figure_, mpl.figure.Figure)
expected_label = f"{default_name} (AUC = {display.roc_auc:.2f})"
assert display.line_.get_label() == expected_label
expected_pos_label = 1 if pos_label is None else pos_label
expected_ylabel = f"True Positive Rate (Positive label: {expected_pos_label})"
expected_xlabel = f"False Positive Rate (Positive label: {expected_pos_label})"
assert display.ax_.get_ylabel() == expected_ylabel
assert display.ax_.get_xlabel() == expected_xlabel
@pytest.mark.parametrize(
"clf",
[
LogisticRegression(),
make_pipeline(StandardScaler(), LogisticRegression()),
make_pipeline(
make_column_transformer((StandardScaler(), [0, 1])), LogisticRegression()
),
],
)
@pytest.mark.parametrize("constructor_name", ["from_estimator", "from_predictions"])
def test_roc_curve_display_complex_pipeline(pyplot, data_binary, clf, constructor_name):
"""Check the behaviour with complex pipeline."""
X, y = data_binary
if constructor_name == "from_estimator":
with pytest.raises(NotFittedError):
RocCurveDisplay.from_estimator(clf, X, y)
clf.fit(X, y)
if constructor_name == "from_estimator":
display = RocCurveDisplay.from_estimator(clf, X, y)
name = clf.__class__.__name__
else:
display = RocCurveDisplay.from_predictions(y, y)
name = "Classifier"
assert name in display.line_.get_label()
assert display.estimator_name == name
@pytest.mark.parametrize(
"roc_auc, estimator_name, expected_label",
[
(0.9, None, "AUC = 0.90"),
(None, "my_est", "my_est"),
(0.8, "my_est2", "my_est2 (AUC = 0.80)"),
],
)
def test_roc_curve_display_default_labels(
pyplot, roc_auc, estimator_name, expected_label
):
"""Check the default labels used in the display."""
fpr = np.array([0, 0.5, 1])
tpr = np.array([0, 0.5, 1])
disp = RocCurveDisplay(
fpr=fpr, tpr=tpr, roc_auc=roc_auc, estimator_name=estimator_name
).plot()
assert disp.line_.get_label() == expected_label
@pytest.mark.parametrize("response_method", ["predict_proba", "decision_function"])
@pytest.mark.parametrize("constructor_name", ["from_estimator", "from_predictions"])
def test_plot_roc_curve_pos_label(pyplot, response_method, constructor_name):
# check that we can provide the positive label and display the proper
# statistics
X, y = load_breast_cancer(return_X_y=True)
# create an highly imbalanced
idx_positive = np.flatnonzero(y == 1)
idx_negative = np.flatnonzero(y == 0)
idx_selected = np.hstack([idx_negative, idx_positive[:25]])
X, y = X[idx_selected], y[idx_selected]
X, y = shuffle(X, y, random_state=42)
# only use 2 features to make the problem even harder
X = X[:, :2]
y = np.array(["cancer" if c == 1 else "not cancer" for c in y], dtype=object)
X_train, X_test, y_train, y_test = train_test_split(
X,
y,
stratify=y,
random_state=0,
)
classifier = LogisticRegression()
classifier.fit(X_train, y_train)
# sanity check to be sure the positive class is classes_[0] and that we
# are betrayed by the class imbalance
assert classifier.classes_.tolist() == ["cancer", "not cancer"]
y_pred = getattr(classifier, response_method)(X_test)
# we select the corresponding probability columns or reverse the decision
# function otherwise
y_pred_cancer = -1 * y_pred if y_pred.ndim == 1 else y_pred[:, 0]
y_pred_not_cancer = y_pred if y_pred.ndim == 1 else y_pred[:, 1]
if constructor_name == "from_estimator":
display = RocCurveDisplay.from_estimator(
classifier,
X_test,
y_test,
pos_label="cancer",
response_method=response_method,
)
else:
display = RocCurveDisplay.from_predictions(
y_test,
y_pred_cancer,
pos_label="cancer",
)
roc_auc_limit = 0.95679
assert display.roc_auc == pytest.approx(roc_auc_limit)
assert np.trapz(display.tpr, display.fpr) == pytest.approx(roc_auc_limit)
if constructor_name == "from_estimator":
display = RocCurveDisplay.from_estimator(
classifier,
X_test,
y_test,
response_method=response_method,
pos_label="not cancer",
)
else:
display = RocCurveDisplay.from_predictions(
y_test,
y_pred_not_cancer,
pos_label="not cancer",
)
assert display.roc_auc == pytest.approx(roc_auc_limit)
assert np.trapz(display.tpr, display.fpr) == pytest.approx(roc_auc_limit)
# FIXME: Remove in 1.2
def test_plot_precision_recall_curve_deprecation(pyplot):
"""Check that we raise a FutureWarning when calling
`plot_roc_curve`."""
X, y = make_classification(random_state=0)
clf = LogisticRegression().fit(X, y)
deprecation_warning = "Function plot_roc_curve is deprecated"
with pytest.warns(FutureWarning, match=deprecation_warning):
plot_roc_curve(clf, X, y)

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"""
The :mod:`sklearn.metrics.scorer` submodule implements a flexible
interface for model selection and evaluation using
arbitrary score functions.
A scorer object is a callable that can be passed to
:class:`~sklearn.model_selection.GridSearchCV` or
:func:`sklearn.model_selection.cross_val_score` as the ``scoring``
parameter, to specify how a model should be evaluated.
The signature of the call is ``(estimator, X, y)`` where ``estimator``
is the model to be evaluated, ``X`` is the test data and ``y`` is the
ground truth labeling (or ``None`` in the case of unsupervised models).
"""
# Authors: Andreas Mueller <amueller@ais.uni-bonn.de>
# Lars Buitinck
# Arnaud Joly <arnaud.v.joly@gmail.com>
# License: Simplified BSD
from collections.abc import Iterable
from functools import partial
from collections import Counter
import numpy as np
import copy
import warnings
from . import (
r2_score,
median_absolute_error,
max_error,
mean_absolute_error,
mean_squared_error,
mean_squared_log_error,
mean_poisson_deviance,
mean_gamma_deviance,
accuracy_score,
top_k_accuracy_score,
f1_score,
roc_auc_score,
average_precision_score,
precision_score,
recall_score,
log_loss,
balanced_accuracy_score,
explained_variance_score,
brier_score_loss,
jaccard_score,
mean_absolute_percentage_error,
matthews_corrcoef,
)
from .cluster import adjusted_rand_score
from .cluster import rand_score
from .cluster import homogeneity_score
from .cluster import completeness_score
from .cluster import v_measure_score
from .cluster import mutual_info_score
from .cluster import adjusted_mutual_info_score
from .cluster import normalized_mutual_info_score
from .cluster import fowlkes_mallows_score
from ..utils.multiclass import type_of_target
from ..base import is_regressor
def _cached_call(cache, estimator, method, *args, **kwargs):
"""Call estimator with method and args and kwargs."""
if cache is None:
return getattr(estimator, method)(*args, **kwargs)
try:
return cache[method]
except KeyError:
result = getattr(estimator, method)(*args, **kwargs)
cache[method] = result
return result
class _MultimetricScorer:
"""Callable for multimetric scoring used to avoid repeated calls
to `predict_proba`, `predict`, and `decision_function`.
`_MultimetricScorer` will return a dictionary of scores corresponding to
the scorers in the dictionary. Note that `_MultimetricScorer` can be
created with a dictionary with one key (i.e. only one actual scorer).
Parameters
----------
scorers : dict
Dictionary mapping names to callable scorers.
"""
def __init__(self, **scorers):
self._scorers = scorers
def __call__(self, estimator, *args, **kwargs):
"""Evaluate predicted target values."""
scores = {}
cache = {} if self._use_cache(estimator) else None
cached_call = partial(_cached_call, cache)
for name, scorer in self._scorers.items():
if isinstance(scorer, _BaseScorer):
score = scorer._score(cached_call, estimator, *args, **kwargs)
else:
score = scorer(estimator, *args, **kwargs)
scores[name] = score
return scores
def _use_cache(self, estimator):
"""Return True if using a cache is beneficial.
Caching may be beneficial when one of these conditions holds:
- `_ProbaScorer` will be called twice.
- `_PredictScorer` will be called twice.
- `_ThresholdScorer` will be called twice.
- `_ThresholdScorer` and `_PredictScorer` are called and
estimator is a regressor.
- `_ThresholdScorer` and `_ProbaScorer` are called and
estimator does not have a `decision_function` attribute.
"""
if len(self._scorers) == 1: # Only one scorer
return False
counter = Counter([type(v) for v in self._scorers.values()])
if any(
counter[known_type] > 1
for known_type in [_PredictScorer, _ProbaScorer, _ThresholdScorer]
):
return True
if counter[_ThresholdScorer]:
if is_regressor(estimator) and counter[_PredictScorer]:
return True
elif counter[_ProbaScorer] and not hasattr(estimator, "decision_function"):
return True
return False
class _BaseScorer:
def __init__(self, score_func, sign, kwargs):
self._kwargs = kwargs
self._score_func = score_func
self._sign = sign
@staticmethod
def _check_pos_label(pos_label, classes):
if pos_label not in list(classes):
raise ValueError(f"pos_label={pos_label} is not a valid label: {classes}")
def _select_proba_binary(self, y_pred, classes):
"""Select the column of the positive label in `y_pred` when
probabilities are provided.
Parameters
----------
y_pred : ndarray of shape (n_samples, n_classes)
The prediction given by `predict_proba`.
classes : ndarray of shape (n_classes,)
The class labels for the estimator.
Returns
-------
y_pred : ndarray of shape (n_samples,)
Probability predictions of the positive class.
"""
if y_pred.shape[1] == 2:
pos_label = self._kwargs.get("pos_label", classes[1])
self._check_pos_label(pos_label, classes)
col_idx = np.flatnonzero(classes == pos_label)[0]
return y_pred[:, col_idx]
err_msg = (
f"Got predict_proba of shape {y_pred.shape}, but need "
f"classifier with two classes for {self._score_func.__name__} "
"scoring"
)
raise ValueError(err_msg)
def __repr__(self):
kwargs_string = "".join(
[", %s=%s" % (str(k), str(v)) for k, v in self._kwargs.items()]
)
return "make_scorer(%s%s%s%s)" % (
self._score_func.__name__,
"" if self._sign > 0 else ", greater_is_better=False",
self._factory_args(),
kwargs_string,
)
def __call__(self, estimator, X, y_true, sample_weight=None):
"""Evaluate predicted target values for X relative to y_true.
Parameters
----------
estimator : object
Trained estimator to use for scoring. Must have a predict_proba
method; the output of that is used to compute the score.
X : {array-like, sparse matrix}
Test data that will be fed to estimator.predict.
y_true : array-like
Gold standard target values for X.
sample_weight : array-like of shape (n_samples,), default=None
Sample weights.
Returns
-------
score : float
Score function applied to prediction of estimator on X.
"""
return self._score(
partial(_cached_call, None),
estimator,
X,
y_true,
sample_weight=sample_weight,
)
def _factory_args(self):
"""Return non-default make_scorer arguments for repr."""
return ""
class _PredictScorer(_BaseScorer):
def _score(self, method_caller, estimator, X, y_true, sample_weight=None):
"""Evaluate predicted target values for X relative to y_true.
Parameters
----------
method_caller : callable
Returns predictions given an estimator, method name, and other
arguments, potentially caching results.
estimator : object
Trained estimator to use for scoring. Must have a `predict`
method; the output of that is used to compute the score.
X : {array-like, sparse matrix}
Test data that will be fed to estimator.predict.
y_true : array-like
Gold standard target values for X.
sample_weight : array-like of shape (n_samples,), default=None
Sample weights.
Returns
-------
score : float
Score function applied to prediction of estimator on X.
"""
y_pred = method_caller(estimator, "predict", X)
if sample_weight is not None:
return self._sign * self._score_func(
y_true, y_pred, sample_weight=sample_weight, **self._kwargs
)
else:
return self._sign * self._score_func(y_true, y_pred, **self._kwargs)
class _ProbaScorer(_BaseScorer):
def _score(self, method_caller, clf, X, y, sample_weight=None):
"""Evaluate predicted probabilities for X relative to y_true.
Parameters
----------
method_caller : callable
Returns predictions given an estimator, method name, and other
arguments, potentially caching results.
clf : object
Trained classifier to use for scoring. Must have a `predict_proba`
method; the output of that is used to compute the score.
X : {array-like, sparse matrix}
Test data that will be fed to clf.predict_proba.
y : array-like
Gold standard target values for X. These must be class labels,
not probabilities.
sample_weight : array-like, default=None
Sample weights.
Returns
-------
score : float
Score function applied to prediction of estimator on X.
"""
y_type = type_of_target(y)
y_pred = method_caller(clf, "predict_proba", X)
if y_type == "binary" and y_pred.shape[1] <= 2:
# `y_type` could be equal to "binary" even in a multi-class
# problem: (when only 2 class are given to `y_true` during scoring)
# Thus, we need to check for the shape of `y_pred`.
y_pred = self._select_proba_binary(y_pred, clf.classes_)
if sample_weight is not None:
return self._sign * self._score_func(
y, y_pred, sample_weight=sample_weight, **self._kwargs
)
else:
return self._sign * self._score_func(y, y_pred, **self._kwargs)
def _factory_args(self):
return ", needs_proba=True"
class _ThresholdScorer(_BaseScorer):
def _score(self, method_caller, clf, X, y, sample_weight=None):
"""Evaluate decision function output for X relative to y_true.
Parameters
----------
method_caller : callable
Returns predictions given an estimator, method name, and other
arguments, potentially caching results.
clf : object
Trained classifier to use for scoring. Must have either a
decision_function method or a predict_proba method; the output of
that is used to compute the score.
X : {array-like, sparse matrix}
Test data that will be fed to clf.decision_function or
clf.predict_proba.
y : array-like
Gold standard target values for X. These must be class labels,
not decision function values.
sample_weight : array-like, default=None
Sample weights.
Returns
-------
score : float
Score function applied to prediction of estimator on X.
"""
y_type = type_of_target(y)
if y_type not in ("binary", "multilabel-indicator"):
raise ValueError("{0} format is not supported".format(y_type))
if is_regressor(clf):
y_pred = method_caller(clf, "predict", X)
else:
try:
y_pred = method_caller(clf, "decision_function", X)
if isinstance(y_pred, list):
# For multi-output multi-class estimator
y_pred = np.vstack([p for p in y_pred]).T
elif y_type == "binary" and "pos_label" in self._kwargs:
self._check_pos_label(self._kwargs["pos_label"], clf.classes_)
if self._kwargs["pos_label"] == clf.classes_[0]:
# The implicit positive class of the binary classifier
# does not match `pos_label`: we need to invert the
# predictions
y_pred *= -1
except (NotImplementedError, AttributeError):
y_pred = method_caller(clf, "predict_proba", X)
if y_type == "binary":
y_pred = self._select_proba_binary(y_pred, clf.classes_)
elif isinstance(y_pred, list):
y_pred = np.vstack([p[:, -1] for p in y_pred]).T
if sample_weight is not None:
return self._sign * self._score_func(
y, y_pred, sample_weight=sample_weight, **self._kwargs
)
else:
return self._sign * self._score_func(y, y_pred, **self._kwargs)
def _factory_args(self):
return ", needs_threshold=True"
def get_scorer(scoring):
"""Get a scorer from string.
Read more in the :ref:`User Guide <scoring_parameter>`.
:func:`~sklearn.metrics.get_scorer_names` can be used to retrieve the names
of all available scorers.
Parameters
----------
scoring : str or callable
Scoring method as string. If callable it is returned as is.
Returns
-------
scorer : callable
The scorer.
Notes
-----
When passed a string, this function always returns a copy of the scorer
object. Calling `get_scorer` twice for the same scorer results in two
separate scorer objects.
"""
if isinstance(scoring, str):
try:
scorer = copy.deepcopy(_SCORERS[scoring])
except KeyError:
raise ValueError(
"%r is not a valid scoring value. "
"Use sklearn.metrics.get_scorer_names() "
"to get valid options." % scoring
)
else:
scorer = scoring
return scorer
def _passthrough_scorer(estimator, *args, **kwargs):
"""Function that wraps estimator.score"""
return estimator.score(*args, **kwargs)
def check_scoring(estimator, scoring=None, *, allow_none=False):
"""Determine scorer from user options.
A TypeError will be thrown if the estimator cannot be scored.
Parameters
----------
estimator : estimator object implementing 'fit'
The object to use to fit the data.
scoring : str or callable, default=None
A string (see model evaluation documentation) or
a scorer callable object / function with signature
``scorer(estimator, X, y)``.
If None, the provided estimator object's `score` method is used.
allow_none : bool, default=False
If no scoring is specified and the estimator has no score function, we
can either return None or raise an exception.
Returns
-------
scoring : callable
A scorer callable object / function with signature
``scorer(estimator, X, y)``.
"""
if not hasattr(estimator, "fit"):
raise TypeError(
"estimator should be an estimator implementing 'fit' method, %r was passed"
% estimator
)
if isinstance(scoring, str):
return get_scorer(scoring)
elif callable(scoring):
# Heuristic to ensure user has not passed a metric
module = getattr(scoring, "__module__", None)
if (
hasattr(module, "startswith")
and module.startswith("sklearn.metrics.")
and not module.startswith("sklearn.metrics._scorer")
and not module.startswith("sklearn.metrics.tests.")
):
raise ValueError(
"scoring value %r looks like it is a metric "
"function rather than a scorer. A scorer should "
"require an estimator as its first parameter. "
"Please use `make_scorer` to convert a metric "
"to a scorer." % scoring
)
return get_scorer(scoring)
elif scoring is None:
if hasattr(estimator, "score"):
return _passthrough_scorer
elif allow_none:
return None
else:
raise TypeError(
"If no scoring is specified, the estimator passed should "
"have a 'score' method. The estimator %r does not." % estimator
)
elif isinstance(scoring, Iterable):
raise ValueError(
"For evaluating multiple scores, use "
"sklearn.model_selection.cross_validate instead. "
"{0} was passed.".format(scoring)
)
else:
raise ValueError(
"scoring value should either be a callable, string or None. %r was passed"
% scoring
)
def _check_multimetric_scoring(estimator, scoring):
"""Check the scoring parameter in cases when multiple metrics are allowed.
Parameters
----------
estimator : sklearn estimator instance
The estimator for which the scoring will be applied.
scoring : list, tuple or dict
Strategy to evaluate the performance of the cross-validated model on
the test set.
The possibilities are:
- a list or tuple of unique strings;
- a callable returning a dictionary where they keys are the metric
names and the values are the metric scores;
- a dictionary with metric names as keys and callables a values.
See :ref:`multimetric_grid_search` for an example.
Returns
-------
scorers_dict : dict
A dict mapping each scorer name to its validated scorer.
"""
err_msg_generic = (
f"scoring is invalid (got {scoring!r}). Refer to the "
"scoring glossary for details: "
"https://scikit-learn.org/stable/glossary.html#term-scoring"
)
if isinstance(scoring, (list, tuple, set)):
err_msg = (
"The list/tuple elements must be unique strings of predefined scorers. "
)
try:
keys = set(scoring)
except TypeError as e:
raise ValueError(err_msg) from e
if len(keys) != len(scoring):
raise ValueError(
f"{err_msg} Duplicate elements were found in"
f" the given list. {scoring!r}"
)
elif len(keys) > 0:
if not all(isinstance(k, str) for k in keys):
if any(callable(k) for k in keys):
raise ValueError(
f"{err_msg} One or more of the elements "
"were callables. Use a dict of score "
"name mapped to the scorer callable. "
f"Got {scoring!r}"
)
else:
raise ValueError(
f"{err_msg} Non-string types were found "
f"in the given list. Got {scoring!r}"
)
scorers = {
scorer: check_scoring(estimator, scoring=scorer) for scorer in scoring
}
else:
raise ValueError(f"{err_msg} Empty list was given. {scoring!r}")
elif isinstance(scoring, dict):
keys = set(scoring)
if not all(isinstance(k, str) for k in keys):
raise ValueError(
"Non-string types were found in the keys of "
f"the given dict. scoring={scoring!r}"
)
if len(keys) == 0:
raise ValueError(f"An empty dict was passed. {scoring!r}")
scorers = {
key: check_scoring(estimator, scoring=scorer)
for key, scorer in scoring.items()
}
else:
raise ValueError(err_msg_generic)
return scorers
def make_scorer(
score_func,
*,
greater_is_better=True,
needs_proba=False,
needs_threshold=False,
**kwargs,
):
"""Make a scorer from a performance metric or loss function.
This factory function wraps scoring functions for use in
:class:`~sklearn.model_selection.GridSearchCV` and
:func:`~sklearn.model_selection.cross_val_score`.
It takes a score function, such as :func:`~sklearn.metrics.accuracy_score`,
:func:`~sklearn.metrics.mean_squared_error`,
:func:`~sklearn.metrics.adjusted_rand_score` or
:func:`~sklearn.metrics.average_precision_score`
and returns a callable that scores an estimator's output.
The signature of the call is `(estimator, X, y)` where `estimator`
is the model to be evaluated, `X` is the data and `y` is the
ground truth labeling (or `None` in the case of unsupervised models).
Read more in the :ref:`User Guide <scoring>`.
Parameters
----------
score_func : callable
Score function (or loss function) with signature
`score_func(y, y_pred, **kwargs)`.
greater_is_better : bool, default=True
Whether `score_func` is a score function (default), meaning high is
good, or a loss function, meaning low is good. In the latter case, the
scorer object will sign-flip the outcome of the `score_func`.
needs_proba : bool, default=False
Whether `score_func` requires `predict_proba` to get probability
estimates out of a classifier.
If True, for binary `y_true`, the score function is supposed to accept
a 1D `y_pred` (i.e., probability of the positive class, shape
`(n_samples,)`).
needs_threshold : bool, default=False
Whether `score_func` takes a continuous decision certainty.
This only works for binary classification using estimators that
have either a `decision_function` or `predict_proba` method.
If True, for binary `y_true`, the score function is supposed to accept
a 1D `y_pred` (i.e., probability of the positive class or the decision
function, shape `(n_samples,)`).
For example `average_precision` or the area under the roc curve
can not be computed using discrete predictions alone.
**kwargs : additional arguments
Additional parameters to be passed to `score_func`.
Returns
-------
scorer : callable
Callable object that returns a scalar score; greater is better.
Notes
-----
If `needs_proba=False` and `needs_threshold=False`, the score
function is supposed to accept the output of :term:`predict`. If
`needs_proba=True`, the score function is supposed to accept the
output of :term:`predict_proba` (For binary `y_true`, the score function is
supposed to accept probability of the positive class). If
`needs_threshold=True`, the score function is supposed to accept the
output of :term:`decision_function` or :term:`predict_proba` when
:term:`decision_function` is not present.
Examples
--------
>>> from sklearn.metrics import fbeta_score, make_scorer
>>> ftwo_scorer = make_scorer(fbeta_score, beta=2)
>>> ftwo_scorer
make_scorer(fbeta_score, beta=2)
>>> from sklearn.model_selection import GridSearchCV
>>> from sklearn.svm import LinearSVC
>>> grid = GridSearchCV(LinearSVC(), param_grid={'C': [1, 10]},
... scoring=ftwo_scorer)
"""
sign = 1 if greater_is_better else -1
if needs_proba and needs_threshold:
raise ValueError(
"Set either needs_proba or needs_threshold to True, but not both."
)
if needs_proba:
cls = _ProbaScorer
elif needs_threshold:
cls = _ThresholdScorer
else:
cls = _PredictScorer
return cls(score_func, sign, kwargs)
# Standard regression scores
explained_variance_scorer = make_scorer(explained_variance_score)
r2_scorer = make_scorer(r2_score)
max_error_scorer = make_scorer(max_error, greater_is_better=False)
neg_mean_squared_error_scorer = make_scorer(mean_squared_error, greater_is_better=False)
neg_mean_squared_log_error_scorer = make_scorer(
mean_squared_log_error, greater_is_better=False
)
neg_mean_absolute_error_scorer = make_scorer(
mean_absolute_error, greater_is_better=False
)
neg_mean_absolute_percentage_error_scorer = make_scorer(
mean_absolute_percentage_error, greater_is_better=False
)
neg_median_absolute_error_scorer = make_scorer(
median_absolute_error, greater_is_better=False
)
neg_root_mean_squared_error_scorer = make_scorer(
mean_squared_error, greater_is_better=False, squared=False
)
neg_mean_poisson_deviance_scorer = make_scorer(
mean_poisson_deviance, greater_is_better=False
)
neg_mean_gamma_deviance_scorer = make_scorer(
mean_gamma_deviance, greater_is_better=False
)
# Standard Classification Scores
accuracy_scorer = make_scorer(accuracy_score)
balanced_accuracy_scorer = make_scorer(balanced_accuracy_score)
matthews_corrcoef_scorer = make_scorer(matthews_corrcoef)
# Score functions that need decision values
top_k_accuracy_scorer = make_scorer(
top_k_accuracy_score, greater_is_better=True, needs_threshold=True
)
roc_auc_scorer = make_scorer(
roc_auc_score, greater_is_better=True, needs_threshold=True
)
average_precision_scorer = make_scorer(average_precision_score, needs_threshold=True)
roc_auc_ovo_scorer = make_scorer(roc_auc_score, needs_proba=True, multi_class="ovo")
roc_auc_ovo_weighted_scorer = make_scorer(
roc_auc_score, needs_proba=True, multi_class="ovo", average="weighted"
)
roc_auc_ovr_scorer = make_scorer(roc_auc_score, needs_proba=True, multi_class="ovr")
roc_auc_ovr_weighted_scorer = make_scorer(
roc_auc_score, needs_proba=True, multi_class="ovr", average="weighted"
)
# Score function for probabilistic classification
neg_log_loss_scorer = make_scorer(log_loss, greater_is_better=False, needs_proba=True)
neg_brier_score_scorer = make_scorer(
brier_score_loss, greater_is_better=False, needs_proba=True
)
brier_score_loss_scorer = make_scorer(
brier_score_loss, greater_is_better=False, needs_proba=True
)
# Clustering scores
adjusted_rand_scorer = make_scorer(adjusted_rand_score)
rand_scorer = make_scorer(rand_score)
homogeneity_scorer = make_scorer(homogeneity_score)
completeness_scorer = make_scorer(completeness_score)
v_measure_scorer = make_scorer(v_measure_score)
mutual_info_scorer = make_scorer(mutual_info_score)
adjusted_mutual_info_scorer = make_scorer(adjusted_mutual_info_score)
normalized_mutual_info_scorer = make_scorer(normalized_mutual_info_score)
fowlkes_mallows_scorer = make_scorer(fowlkes_mallows_score)
# TODO(1.3) Remove
class _DeprecatedScorers(dict):
"""A temporary class to deprecate SCORERS."""
def __getitem__(self, item):
warnings.warn(
"sklearn.metrics.SCORERS is deprecated and will be removed in v1.3. "
"Please use sklearn.metrics.get_scorer_names to get a list of available "
"scorers and sklearn.metrics.get_metric to get scorer.",
FutureWarning,
)
return super().__getitem__(item)
_SCORERS = dict(
explained_variance=explained_variance_scorer,
r2=r2_scorer,
max_error=max_error_scorer,
matthews_corrcoef=matthews_corrcoef_scorer,
neg_median_absolute_error=neg_median_absolute_error_scorer,
neg_mean_absolute_error=neg_mean_absolute_error_scorer,
neg_mean_absolute_percentage_error=neg_mean_absolute_percentage_error_scorer, # noqa
neg_mean_squared_error=neg_mean_squared_error_scorer,
neg_mean_squared_log_error=neg_mean_squared_log_error_scorer,
neg_root_mean_squared_error=neg_root_mean_squared_error_scorer,
neg_mean_poisson_deviance=neg_mean_poisson_deviance_scorer,
neg_mean_gamma_deviance=neg_mean_gamma_deviance_scorer,
accuracy=accuracy_scorer,
top_k_accuracy=top_k_accuracy_scorer,
roc_auc=roc_auc_scorer,
roc_auc_ovr=roc_auc_ovr_scorer,
roc_auc_ovo=roc_auc_ovo_scorer,
roc_auc_ovr_weighted=roc_auc_ovr_weighted_scorer,
roc_auc_ovo_weighted=roc_auc_ovo_weighted_scorer,
balanced_accuracy=balanced_accuracy_scorer,
average_precision=average_precision_scorer,
neg_log_loss=neg_log_loss_scorer,
neg_brier_score=neg_brier_score_scorer,
# Cluster metrics that use supervised evaluation
adjusted_rand_score=adjusted_rand_scorer,
rand_score=rand_scorer,
homogeneity_score=homogeneity_scorer,
completeness_score=completeness_scorer,
v_measure_score=v_measure_scorer,
mutual_info_score=mutual_info_scorer,
adjusted_mutual_info_score=adjusted_mutual_info_scorer,
normalized_mutual_info_score=normalized_mutual_info_scorer,
fowlkes_mallows_score=fowlkes_mallows_scorer,
)
def get_scorer_names():
"""Get the names of all available scorers.
These names can be passed to :func:`~sklearn.metrics.get_scorer` to
retrieve the scorer object.
Returns
-------
list of str
Names of all available scorers.
"""
return sorted(_SCORERS.keys())
for name, metric in [
("precision", precision_score),
("recall", recall_score),
("f1", f1_score),
("jaccard", jaccard_score),
]:
_SCORERS[name] = make_scorer(metric, average="binary")
for average in ["macro", "micro", "samples", "weighted"]:
qualified_name = "{0}_{1}".format(name, average)
_SCORERS[qualified_name] = make_scorer(metric, pos_label=None, average=average)
SCORERS = _DeprecatedScorers(_SCORERS)

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@@ -0,0 +1,48 @@
"""
The :mod:`sklearn.metrics.cluster` submodule contains evaluation metrics for
cluster analysis results. There are two forms of evaluation:
- supervised, which uses a ground truth class values for each sample.
- unsupervised, which does not and measures the 'quality' of the model itself.
"""
from ._supervised import adjusted_mutual_info_score
from ._supervised import normalized_mutual_info_score
from ._supervised import adjusted_rand_score
from ._supervised import rand_score
from ._supervised import completeness_score
from ._supervised import contingency_matrix
from ._supervised import pair_confusion_matrix
from ._supervised import expected_mutual_information
from ._supervised import homogeneity_completeness_v_measure
from ._supervised import homogeneity_score
from ._supervised import mutual_info_score
from ._supervised import v_measure_score
from ._supervised import fowlkes_mallows_score
from ._supervised import entropy
from ._unsupervised import silhouette_samples
from ._unsupervised import silhouette_score
from ._unsupervised import calinski_harabasz_score
from ._unsupervised import davies_bouldin_score
from ._bicluster import consensus_score
__all__ = [
"adjusted_mutual_info_score",
"normalized_mutual_info_score",
"adjusted_rand_score",
"rand_score",
"completeness_score",
"pair_confusion_matrix",
"contingency_matrix",
"expected_mutual_information",
"homogeneity_completeness_v_measure",
"homogeneity_score",
"mutual_info_score",
"v_measure_score",
"fowlkes_mallows_score",
"entropy",
"silhouette_samples",
"silhouette_score",
"calinski_harabasz_score",
"davies_bouldin_score",
"consensus_score",
]

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import numpy as np
from scipy.optimize import linear_sum_assignment
from ...utils.validation import check_consistent_length, check_array
__all__ = ["consensus_score"]
def _check_rows_and_columns(a, b):
"""Unpacks the row and column arrays and checks their shape."""
check_consistent_length(*a)
check_consistent_length(*b)
checks = lambda x: check_array(x, ensure_2d=False)
a_rows, a_cols = map(checks, a)
b_rows, b_cols = map(checks, b)
return a_rows, a_cols, b_rows, b_cols
def _jaccard(a_rows, a_cols, b_rows, b_cols):
"""Jaccard coefficient on the elements of the two biclusters."""
intersection = (a_rows * b_rows).sum() * (a_cols * b_cols).sum()
a_size = a_rows.sum() * a_cols.sum()
b_size = b_rows.sum() * b_cols.sum()
return intersection / (a_size + b_size - intersection)
def _pairwise_similarity(a, b, similarity):
"""Computes pairwise similarity matrix.
result[i, j] is the Jaccard coefficient of a's bicluster i and b's
bicluster j.
"""
a_rows, a_cols, b_rows, b_cols = _check_rows_and_columns(a, b)
n_a = a_rows.shape[0]
n_b = b_rows.shape[0]
result = np.array(
list(
list(
similarity(a_rows[i], a_cols[i], b_rows[j], b_cols[j])
for j in range(n_b)
)
for i in range(n_a)
)
)
return result
def consensus_score(a, b, *, similarity="jaccard"):
"""The similarity of two sets of biclusters.
Similarity between individual biclusters is computed. Then the
best matching between sets is found using the Hungarian algorithm.
The final score is the sum of similarities divided by the size of
the larger set.
Read more in the :ref:`User Guide <biclustering>`.
Parameters
----------
a : (rows, columns)
Tuple of row and column indicators for a set of biclusters.
b : (rows, columns)
Another set of biclusters like ``a``.
similarity : 'jaccard' or callable, default='jaccard'
May be the string "jaccard" to use the Jaccard coefficient, or
any function that takes four arguments, each of which is a 1d
indicator vector: (a_rows, a_columns, b_rows, b_columns).
References
----------
* Hochreiter, Bodenhofer, et. al., 2010. `FABIA: factor analysis
for bicluster acquisition
<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2881408/>`__.
"""
if similarity == "jaccard":
similarity = _jaccard
matrix = _pairwise_similarity(a, b, similarity)
row_indices, col_indices = linear_sum_assignment(1.0 - matrix)
n_a = len(a[0])
n_b = len(b[0])
return matrix[row_indices, col_indices].sum() / max(n_a, n_b)

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@@ -0,0 +1,366 @@
"""Unsupervised evaluation metrics."""
# Authors: Robert Layton <robertlayton@gmail.com>
# Arnaud Fouchet <foucheta@gmail.com>
# Thierry Guillemot <thierry.guillemot.work@gmail.com>
# License: BSD 3 clause
import functools
import numpy as np
from ...utils import check_random_state
from ...utils import check_X_y
from ...utils import _safe_indexing
from ..pairwise import pairwise_distances_chunked
from ..pairwise import pairwise_distances
from ...preprocessing import LabelEncoder
def check_number_of_labels(n_labels, n_samples):
"""Check that number of labels are valid.
Parameters
----------
n_labels : int
Number of labels.
n_samples : int
Number of samples.
"""
if not 1 < n_labels < n_samples:
raise ValueError(
"Number of labels is %d. Valid values are 2 to n_samples - 1 (inclusive)"
% n_labels
)
def silhouette_score(
X, labels, *, metric="euclidean", sample_size=None, random_state=None, **kwds
):
"""Compute the mean Silhouette Coefficient of all samples.
The Silhouette Coefficient is calculated using the mean intra-cluster
distance (``a``) and the mean nearest-cluster distance (``b``) for each
sample. The Silhouette Coefficient for a sample is ``(b - a) / max(a,
b)``. To clarify, ``b`` is the distance between a sample and the nearest
cluster that the sample is not a part of.
Note that Silhouette Coefficient is only defined if number of labels
is ``2 <= n_labels <= n_samples - 1``.
This function returns the mean Silhouette Coefficient over all samples.
To obtain the values for each sample, use :func:`silhouette_samples`.
The best value is 1 and the worst value is -1. Values near 0 indicate
overlapping clusters. Negative values generally indicate that a sample has
been assigned to the wrong cluster, as a different cluster is more similar.
Read more in the :ref:`User Guide <silhouette_coefficient>`.
Parameters
----------
X : array-like of shape (n_samples_a, n_samples_a) if metric == \
"precomputed" or (n_samples_a, n_features) otherwise
An array of pairwise distances between samples, or a feature array.
labels : array-like of shape (n_samples,)
Predicted labels for each sample.
metric : str or callable, default='euclidean'
The metric to use when calculating distance between instances in a
feature array. If metric is a string, it must be one of the options
allowed by :func:`metrics.pairwise.pairwise_distances
<sklearn.metrics.pairwise.pairwise_distances>`. If ``X`` is
the distance array itself, use ``metric="precomputed"``.
sample_size : int, default=None
The size of the sample to use when computing the Silhouette Coefficient
on a random subset of the data.
If ``sample_size is None``, no sampling is used.
random_state : int, RandomState instance or None, default=None
Determines random number generation for selecting a subset of samples.
Used when ``sample_size is not None``.
Pass an int for reproducible results across multiple function calls.
See :term:`Glossary <random_state>`.
**kwds : optional keyword parameters
Any further parameters are passed directly to the distance function.
If using a scipy.spatial.distance metric, the parameters are still
metric dependent. See the scipy docs for usage examples.
Returns
-------
silhouette : float
Mean Silhouette Coefficient for all samples.
References
----------
.. [1] `Peter J. Rousseeuw (1987). "Silhouettes: a Graphical Aid to the
Interpretation and Validation of Cluster Analysis". Computational
and Applied Mathematics 20: 53-65.
<https://www.sciencedirect.com/science/article/pii/0377042787901257>`_
.. [2] `Wikipedia entry on the Silhouette Coefficient
<https://en.wikipedia.org/wiki/Silhouette_(clustering)>`_
"""
if sample_size is not None:
X, labels = check_X_y(X, labels, accept_sparse=["csc", "csr"])
random_state = check_random_state(random_state)
indices = random_state.permutation(X.shape[0])[:sample_size]
if metric == "precomputed":
X, labels = X[indices].T[indices].T, labels[indices]
else:
X, labels = X[indices], labels[indices]
return np.mean(silhouette_samples(X, labels, metric=metric, **kwds))
def _silhouette_reduce(D_chunk, start, labels, label_freqs):
"""Accumulate silhouette statistics for vertical chunk of X.
Parameters
----------
D_chunk : array-like of shape (n_chunk_samples, n_samples)
Precomputed distances for a chunk.
start : int
First index in the chunk.
labels : array-like of shape (n_samples,)
Corresponding cluster labels, encoded as {0, ..., n_clusters-1}.
label_freqs : array-like
Distribution of cluster labels in ``labels``.
"""
# accumulate distances from each sample to each cluster
clust_dists = np.zeros((len(D_chunk), len(label_freqs)), dtype=D_chunk.dtype)
for i in range(len(D_chunk)):
clust_dists[i] += np.bincount(
labels, weights=D_chunk[i], minlength=len(label_freqs)
)
# intra_index selects intra-cluster distances within clust_dists
intra_index = (np.arange(len(D_chunk)), labels[start : start + len(D_chunk)])
# intra_clust_dists are averaged over cluster size outside this function
intra_clust_dists = clust_dists[intra_index]
# of the remaining distances we normalise and extract the minimum
clust_dists[intra_index] = np.inf
clust_dists /= label_freqs
inter_clust_dists = clust_dists.min(axis=1)
return intra_clust_dists, inter_clust_dists
def silhouette_samples(X, labels, *, metric="euclidean", **kwds):
"""Compute the Silhouette Coefficient for each sample.
The Silhouette Coefficient is a measure of how well samples are clustered
with samples that are similar to themselves. Clustering models with a high
Silhouette Coefficient are said to be dense, where samples in the same
cluster are similar to each other, and well separated, where samples in
different clusters are not very similar to each other.
The Silhouette Coefficient is calculated using the mean intra-cluster
distance (``a``) and the mean nearest-cluster distance (``b``) for each
sample. The Silhouette Coefficient for a sample is ``(b - a) / max(a,
b)``.
Note that Silhouette Coefficient is only defined if number of labels
is 2 ``<= n_labels <= n_samples - 1``.
This function returns the Silhouette Coefficient for each sample.
The best value is 1 and the worst value is -1. Values near 0 indicate
overlapping clusters.
Read more in the :ref:`User Guide <silhouette_coefficient>`.
Parameters
----------
X : array-like of shape (n_samples_a, n_samples_a) if metric == \
"precomputed" or (n_samples_a, n_features) otherwise
An array of pairwise distances between samples, or a feature array.
labels : array-like of shape (n_samples,)
Label values for each sample.
metric : str or callable, default='euclidean'
The metric to use when calculating distance between instances in a
feature array. If metric is a string, it must be one of the options
allowed by :func:`sklearn.metrics.pairwise.pairwise_distances`.
If ``X`` is the distance array itself, use "precomputed" as the metric.
Precomputed distance matrices must have 0 along the diagonal.
**kwds : optional keyword parameters
Any further parameters are passed directly to the distance function.
If using a ``scipy.spatial.distance`` metric, the parameters are still
metric dependent. See the scipy docs for usage examples.
Returns
-------
silhouette : array-like of shape (n_samples,)
Silhouette Coefficients for each sample.
References
----------
.. [1] `Peter J. Rousseeuw (1987). "Silhouettes: a Graphical Aid to the
Interpretation and Validation of Cluster Analysis". Computational
and Applied Mathematics 20: 53-65.
<https://www.sciencedirect.com/science/article/pii/0377042787901257>`_
.. [2] `Wikipedia entry on the Silhouette Coefficient
<https://en.wikipedia.org/wiki/Silhouette_(clustering)>`_
"""
X, labels = check_X_y(X, labels, accept_sparse=["csc", "csr"])
# Check for non-zero diagonal entries in precomputed distance matrix
if metric == "precomputed":
error_msg = ValueError(
"The precomputed distance matrix contains non-zero "
"elements on the diagonal. Use np.fill_diagonal(X, 0)."
)
if X.dtype.kind == "f":
atol = np.finfo(X.dtype).eps * 100
if np.any(np.abs(np.diagonal(X)) > atol):
raise ValueError(error_msg)
elif np.any(np.diagonal(X) != 0): # integral dtype
raise ValueError(error_msg)
le = LabelEncoder()
labels = le.fit_transform(labels)
n_samples = len(labels)
label_freqs = np.bincount(labels)
check_number_of_labels(len(le.classes_), n_samples)
kwds["metric"] = metric
reduce_func = functools.partial(
_silhouette_reduce, labels=labels, label_freqs=label_freqs
)
results = zip(*pairwise_distances_chunked(X, reduce_func=reduce_func, **kwds))
intra_clust_dists, inter_clust_dists = results
intra_clust_dists = np.concatenate(intra_clust_dists)
inter_clust_dists = np.concatenate(inter_clust_dists)
denom = (label_freqs - 1).take(labels, mode="clip")
with np.errstate(divide="ignore", invalid="ignore"):
intra_clust_dists /= denom
sil_samples = inter_clust_dists - intra_clust_dists
with np.errstate(divide="ignore", invalid="ignore"):
sil_samples /= np.maximum(intra_clust_dists, inter_clust_dists)
# nan values are for clusters of size 1, and should be 0
return np.nan_to_num(sil_samples)
def calinski_harabasz_score(X, labels):
"""Compute the Calinski and Harabasz score.
It is also known as the Variance Ratio Criterion.
The score is defined as ratio of the sum of between-cluster dispersion and
of within-cluster dispersion.
Read more in the :ref:`User Guide <calinski_harabasz_index>`.
Parameters
----------
X : array-like of shape (n_samples, n_features)
A list of ``n_features``-dimensional data points. Each row corresponds
to a single data point.
labels : array-like of shape (n_samples,)
Predicted labels for each sample.
Returns
-------
score : float
The resulting Calinski-Harabasz score.
References
----------
.. [1] `T. Calinski and J. Harabasz, 1974. "A dendrite method for cluster
analysis". Communications in Statistics
<https://www.tandfonline.com/doi/abs/10.1080/03610927408827101>`_
"""
X, labels = check_X_y(X, labels)
le = LabelEncoder()
labels = le.fit_transform(labels)
n_samples, _ = X.shape
n_labels = len(le.classes_)
check_number_of_labels(n_labels, n_samples)
extra_disp, intra_disp = 0.0, 0.0
mean = np.mean(X, axis=0)
for k in range(n_labels):
cluster_k = X[labels == k]
mean_k = np.mean(cluster_k, axis=0)
extra_disp += len(cluster_k) * np.sum((mean_k - mean) ** 2)
intra_disp += np.sum((cluster_k - mean_k) ** 2)
return (
1.0
if intra_disp == 0.0
else extra_disp * (n_samples - n_labels) / (intra_disp * (n_labels - 1.0))
)
def davies_bouldin_score(X, labels):
"""Compute the Davies-Bouldin score.
The score is defined as the average similarity measure of each cluster with
its most similar cluster, where similarity is the ratio of within-cluster
distances to between-cluster distances. Thus, clusters which are farther
apart and less dispersed will result in a better score.
The minimum score is zero, with lower values indicating better clustering.
Read more in the :ref:`User Guide <davies-bouldin_index>`.
.. versionadded:: 0.20
Parameters
----------
X : array-like of shape (n_samples, n_features)
A list of ``n_features``-dimensional data points. Each row corresponds
to a single data point.
labels : array-like of shape (n_samples,)
Predicted labels for each sample.
Returns
-------
score: float
The resulting Davies-Bouldin score.
References
----------
.. [1] Davies, David L.; Bouldin, Donald W. (1979).
`"A Cluster Separation Measure"
<https://ieeexplore.ieee.org/document/4766909>`__.
IEEE Transactions on Pattern Analysis and Machine Intelligence.
PAMI-1 (2): 224-227
"""
X, labels = check_X_y(X, labels)
le = LabelEncoder()
labels = le.fit_transform(labels)
n_samples, _ = X.shape
n_labels = len(le.classes_)
check_number_of_labels(n_labels, n_samples)
intra_dists = np.zeros(n_labels)
centroids = np.zeros((n_labels, len(X[0])), dtype=float)
for k in range(n_labels):
cluster_k = _safe_indexing(X, labels == k)
centroid = cluster_k.mean(axis=0)
centroids[k] = centroid
intra_dists[k] = np.average(pairwise_distances(cluster_k, [centroid]))
centroid_distances = pairwise_distances(centroids)
if np.allclose(intra_dists, 0) or np.allclose(centroid_distances, 0):
return 0.0
centroid_distances[centroid_distances == 0] = np.inf
combined_intra_dists = intra_dists[:, None] + intra_dists
scores = np.max(combined_intra_dists / centroid_distances, axis=1)
return np.mean(scores)

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import os
import numpy
from numpy.distutils.misc_util import Configuration
def configuration(parent_package="", top_path=None):
config = Configuration("cluster", parent_package, top_path)
libraries = []
if os.name == "posix":
libraries.append("m")
config.add_extension(
"_expected_mutual_info_fast",
sources=["_expected_mutual_info_fast.pyx"],
include_dirs=[numpy.get_include()],
libraries=libraries,
)
config.add_subpackage("tests")
return config
if __name__ == "__main__":
from numpy.distutils.core import setup
setup(**configuration().todict())

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"""Testing for bicluster metrics module"""
import numpy as np
from sklearn.utils._testing import assert_almost_equal
from sklearn.metrics.cluster._bicluster import _jaccard
from sklearn.metrics import consensus_score
def test_jaccard():
a1 = np.array([True, True, False, False])
a2 = np.array([True, True, True, True])
a3 = np.array([False, True, True, False])
a4 = np.array([False, False, True, True])
assert _jaccard(a1, a1, a1, a1) == 1
assert _jaccard(a1, a1, a2, a2) == 0.25
assert _jaccard(a1, a1, a3, a3) == 1.0 / 7
assert _jaccard(a1, a1, a4, a4) == 0
def test_consensus_score():
a = [[True, True, False, False], [False, False, True, True]]
b = a[::-1]
assert consensus_score((a, a), (a, a)) == 1
assert consensus_score((a, a), (b, b)) == 1
assert consensus_score((a, b), (a, b)) == 1
assert consensus_score((a, b), (b, a)) == 1
assert consensus_score((a, a), (b, a)) == 0
assert consensus_score((a, a), (a, b)) == 0
assert consensus_score((b, b), (a, b)) == 0
assert consensus_score((b, b), (b, a)) == 0
def test_consensus_score_issue2445():
"""Different number of biclusters in A and B"""
a_rows = np.array(
[
[True, True, False, False],
[False, False, True, True],
[False, False, False, True],
]
)
a_cols = np.array(
[
[True, True, False, False],
[False, False, True, True],
[False, False, False, True],
]
)
idx = [0, 2]
s = consensus_score((a_rows, a_cols), (a_rows[idx], a_cols[idx]))
# B contains 2 of the 3 biclusters in A, so score should be 2/3
assert_almost_equal(s, 2.0 / 3.0)

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from functools import partial
from itertools import chain
import pytest
import numpy as np
from sklearn.metrics.cluster import adjusted_mutual_info_score
from sklearn.metrics.cluster import adjusted_rand_score
from sklearn.metrics.cluster import rand_score
from sklearn.metrics.cluster import completeness_score
from sklearn.metrics.cluster import fowlkes_mallows_score
from sklearn.metrics.cluster import homogeneity_score
from sklearn.metrics.cluster import mutual_info_score
from sklearn.metrics.cluster import normalized_mutual_info_score
from sklearn.metrics.cluster import v_measure_score
from sklearn.metrics.cluster import silhouette_score
from sklearn.metrics.cluster import calinski_harabasz_score
from sklearn.metrics.cluster import davies_bouldin_score
from sklearn.utils._testing import assert_allclose
# Dictionaries of metrics
# ------------------------
# The goal of having those dictionaries is to have an easy way to call a
# particular metric and associate a name to each function:
# - SUPERVISED_METRICS: all supervised cluster metrics - (when given a
# ground truth value)
# - UNSUPERVISED_METRICS: all unsupervised cluster metrics
#
# Those dictionaries will be used to test systematically some invariance
# properties, e.g. invariance toward several input layout.
#
SUPERVISED_METRICS = {
"adjusted_mutual_info_score": adjusted_mutual_info_score,
"adjusted_rand_score": adjusted_rand_score,
"rand_score": rand_score,
"completeness_score": completeness_score,
"homogeneity_score": homogeneity_score,
"mutual_info_score": mutual_info_score,
"normalized_mutual_info_score": normalized_mutual_info_score,
"v_measure_score": v_measure_score,
"fowlkes_mallows_score": fowlkes_mallows_score,
}
UNSUPERVISED_METRICS = {
"silhouette_score": silhouette_score,
"silhouette_manhattan": partial(silhouette_score, metric="manhattan"),
"calinski_harabasz_score": calinski_harabasz_score,
"davies_bouldin_score": davies_bouldin_score,
}
# Lists of metrics with common properties
# ---------------------------------------
# Lists of metrics with common properties are used to test systematically some
# functionalities and invariance, e.g. SYMMETRIC_METRICS lists all metrics
# that are symmetric with respect to their input argument y_true and y_pred.
#
# --------------------------------------------------------------------
# Symmetric with respect to their input arguments y_true and y_pred.
# Symmetric metrics only apply to supervised clusters.
SYMMETRIC_METRICS = [
"adjusted_rand_score",
"rand_score",
"v_measure_score",
"mutual_info_score",
"adjusted_mutual_info_score",
"normalized_mutual_info_score",
"fowlkes_mallows_score",
]
NON_SYMMETRIC_METRICS = ["homogeneity_score", "completeness_score"]
# Metrics whose upper bound is 1
NORMALIZED_METRICS = [
"adjusted_rand_score",
"rand_score",
"homogeneity_score",
"completeness_score",
"v_measure_score",
"adjusted_mutual_info_score",
"fowlkes_mallows_score",
"normalized_mutual_info_score",
]
rng = np.random.RandomState(0)
y1 = rng.randint(3, size=30)
y2 = rng.randint(3, size=30)
def test_symmetric_non_symmetric_union():
assert sorted(SYMMETRIC_METRICS + NON_SYMMETRIC_METRICS) == sorted(
SUPERVISED_METRICS
)
# 0.22 AMI and NMI changes
@pytest.mark.filterwarnings("ignore::FutureWarning")
@pytest.mark.parametrize(
"metric_name, y1, y2", [(name, y1, y2) for name in SYMMETRIC_METRICS]
)
def test_symmetry(metric_name, y1, y2):
metric = SUPERVISED_METRICS[metric_name]
assert metric(y1, y2) == pytest.approx(metric(y2, y1))
@pytest.mark.parametrize(
"metric_name, y1, y2", [(name, y1, y2) for name in NON_SYMMETRIC_METRICS]
)
def test_non_symmetry(metric_name, y1, y2):
metric = SUPERVISED_METRICS[metric_name]
assert metric(y1, y2) != pytest.approx(metric(y2, y1))
# 0.22 AMI and NMI changes
@pytest.mark.filterwarnings("ignore::FutureWarning")
@pytest.mark.parametrize("metric_name", NORMALIZED_METRICS)
def test_normalized_output(metric_name):
upper_bound_1 = [0, 0, 0, 1, 1, 1]
upper_bound_2 = [0, 0, 0, 1, 1, 1]
metric = SUPERVISED_METRICS[metric_name]
assert metric([0, 0, 0, 1, 1], [0, 0, 0, 1, 2]) > 0.0
assert metric([0, 0, 1, 1, 2], [0, 0, 1, 1, 1]) > 0.0
assert metric([0, 0, 0, 1, 2], [0, 1, 1, 1, 1]) < 1.0
assert metric([0, 0, 0, 1, 2], [0, 1, 1, 1, 1]) < 1.0
assert metric(upper_bound_1, upper_bound_2) == pytest.approx(1.0)
lower_bound_1 = [0, 0, 0, 0, 0, 0]
lower_bound_2 = [0, 1, 2, 3, 4, 5]
score = np.array(
[metric(lower_bound_1, lower_bound_2), metric(lower_bound_2, lower_bound_1)]
)
assert not (score < 0).any()
# 0.22 AMI and NMI changes
@pytest.mark.filterwarnings("ignore::FutureWarning")
@pytest.mark.parametrize("metric_name", chain(SUPERVISED_METRICS, UNSUPERVISED_METRICS))
def test_permute_labels(metric_name):
# All clustering metrics do not change score due to permutations of labels
# that is when 0 and 1 exchanged.
y_label = np.array([0, 0, 0, 1, 1, 0, 1])
y_pred = np.array([1, 0, 1, 0, 1, 1, 0])
if metric_name in SUPERVISED_METRICS:
metric = SUPERVISED_METRICS[metric_name]
score_1 = metric(y_pred, y_label)
assert_allclose(score_1, metric(1 - y_pred, y_label))
assert_allclose(score_1, metric(1 - y_pred, 1 - y_label))
assert_allclose(score_1, metric(y_pred, 1 - y_label))
else:
metric = UNSUPERVISED_METRICS[metric_name]
X = np.random.randint(10, size=(7, 10))
score_1 = metric(X, y_pred)
assert_allclose(score_1, metric(X, 1 - y_pred))
# 0.22 AMI and NMI changes
@pytest.mark.filterwarnings("ignore::FutureWarning")
@pytest.mark.parametrize("metric_name", chain(SUPERVISED_METRICS, UNSUPERVISED_METRICS))
# For all clustering metrics Input parameters can be both
# in the form of arrays lists, positive, negative or string
def test_format_invariance(metric_name):
y_true = [0, 0, 0, 0, 1, 1, 1, 1]
y_pred = [0, 1, 2, 3, 4, 5, 6, 7]
def generate_formats(y):
y = np.array(y)
yield y, "array of ints"
yield y.tolist(), "list of ints"
yield [str(x) + "-a" for x in y.tolist()], "list of strs"
yield (
np.array([str(x) + "-a" for x in y.tolist()], dtype=object),
"array of strs",
)
yield y - 1, "including negative ints"
yield y + 1, "strictly positive ints"
if metric_name in SUPERVISED_METRICS:
metric = SUPERVISED_METRICS[metric_name]
score_1 = metric(y_true, y_pred)
y_true_gen = generate_formats(y_true)
y_pred_gen = generate_formats(y_pred)
for (y_true_fmt, fmt_name), (y_pred_fmt, _) in zip(y_true_gen, y_pred_gen):
assert score_1 == metric(y_true_fmt, y_pred_fmt)
else:
metric = UNSUPERVISED_METRICS[metric_name]
X = np.random.randint(10, size=(8, 10))
score_1 = metric(X, y_true)
assert score_1 == metric(X.astype(float), y_true)
y_true_gen = generate_formats(y_true)
for y_true_fmt, fmt_name in y_true_gen:
assert score_1 == metric(X, y_true_fmt)
@pytest.mark.parametrize("metric", SUPERVISED_METRICS.values())
def test_single_sample(metric):
# only the supervised metrics support single sample
for i, j in [(0, 0), (0, 1), (1, 0), (1, 1)]:
metric([i], [j])
@pytest.mark.parametrize(
"metric_name, metric_func", dict(SUPERVISED_METRICS, **UNSUPERVISED_METRICS).items()
)
def test_inf_nan_input(metric_name, metric_func):
if metric_name in SUPERVISED_METRICS:
invalids = [
([0, 1], [np.inf, np.inf]),
([0, 1], [np.nan, np.nan]),
([0, 1], [np.nan, np.inf]),
]
else:
X = np.random.randint(10, size=(2, 10))
invalids = [(X, [np.inf, np.inf]), (X, [np.nan, np.nan]), (X, [np.nan, np.inf])]
with pytest.raises(ValueError, match=r"contains (NaN|infinity)"):
for args in invalids:
metric_func(*args)

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import warnings
import numpy as np
import pytest
from sklearn.metrics.cluster import adjusted_mutual_info_score
from sklearn.metrics.cluster import adjusted_rand_score
from sklearn.metrics.cluster import rand_score
from sklearn.metrics.cluster import completeness_score
from sklearn.metrics.cluster import contingency_matrix
from sklearn.metrics.cluster import pair_confusion_matrix
from sklearn.metrics.cluster import entropy
from sklearn.metrics.cluster import expected_mutual_information
from sklearn.metrics.cluster import fowlkes_mallows_score
from sklearn.metrics.cluster import homogeneity_completeness_v_measure
from sklearn.metrics.cluster import homogeneity_score
from sklearn.metrics.cluster import mutual_info_score
from sklearn.metrics.cluster import normalized_mutual_info_score
from sklearn.metrics.cluster import v_measure_score
from sklearn.metrics.cluster._supervised import _generalized_average
from sklearn.metrics.cluster._supervised import check_clusterings
from sklearn.utils import assert_all_finite
from sklearn.utils._testing import assert_almost_equal
from numpy.testing import assert_array_equal, assert_array_almost_equal, assert_allclose
score_funcs = [
adjusted_rand_score,
rand_score,
homogeneity_score,
completeness_score,
v_measure_score,
adjusted_mutual_info_score,
normalized_mutual_info_score,
]
def test_error_messages_on_wrong_input():
for score_func in score_funcs:
expected = (
r"Found input variables with inconsistent numbers " r"of samples: \[2, 3\]"
)
with pytest.raises(ValueError, match=expected):
score_func([0, 1], [1, 1, 1])
expected = r"labels_true must be 1D: shape is \(2"
with pytest.raises(ValueError, match=expected):
score_func([[0, 1], [1, 0]], [1, 1, 1])
expected = r"labels_pred must be 1D: shape is \(2"
with pytest.raises(ValueError, match=expected):
score_func([0, 1, 0], [[1, 1], [0, 0]])
def test_generalized_average():
a, b = 1, 2
methods = ["min", "geometric", "arithmetic", "max"]
means = [_generalized_average(a, b, method) for method in methods]
assert means[0] <= means[1] <= means[2] <= means[3]
c, d = 12, 12
means = [_generalized_average(c, d, method) for method in methods]
assert means[0] == means[1] == means[2] == means[3]
def test_perfect_matches():
for score_func in score_funcs:
assert score_func([], []) == pytest.approx(1.0)
assert score_func([0], [1]) == pytest.approx(1.0)
assert score_func([0, 0, 0], [0, 0, 0]) == pytest.approx(1.0)
assert score_func([0, 1, 0], [42, 7, 42]) == pytest.approx(1.0)
assert score_func([0.0, 1.0, 0.0], [42.0, 7.0, 42.0]) == pytest.approx(1.0)
assert score_func([0.0, 1.0, 2.0], [42.0, 7.0, 2.0]) == pytest.approx(1.0)
assert score_func([0, 1, 2], [42, 7, 2]) == pytest.approx(1.0)
score_funcs_with_changing_means = [
normalized_mutual_info_score,
adjusted_mutual_info_score,
]
means = {"min", "geometric", "arithmetic", "max"}
for score_func in score_funcs_with_changing_means:
for mean in means:
assert score_func([], [], average_method=mean) == pytest.approx(1.0)
assert score_func([0], [1], average_method=mean) == pytest.approx(1.0)
assert score_func(
[0, 0, 0], [0, 0, 0], average_method=mean
) == pytest.approx(1.0)
assert score_func(
[0, 1, 0], [42, 7, 42], average_method=mean
) == pytest.approx(1.0)
assert score_func(
[0.0, 1.0, 0.0], [42.0, 7.0, 42.0], average_method=mean
) == pytest.approx(1.0)
assert score_func(
[0.0, 1.0, 2.0], [42.0, 7.0, 2.0], average_method=mean
) == pytest.approx(1.0)
assert score_func(
[0, 1, 2], [42, 7, 2], average_method=mean
) == pytest.approx(1.0)
def test_homogeneous_but_not_complete_labeling():
# homogeneous but not complete clustering
h, c, v = homogeneity_completeness_v_measure([0, 0, 0, 1, 1, 1], [0, 0, 0, 1, 2, 2])
assert_almost_equal(h, 1.00, 2)
assert_almost_equal(c, 0.69, 2)
assert_almost_equal(v, 0.81, 2)
def test_complete_but_not_homogeneous_labeling():
# complete but not homogeneous clustering
h, c, v = homogeneity_completeness_v_measure([0, 0, 1, 1, 2, 2], [0, 0, 1, 1, 1, 1])
assert_almost_equal(h, 0.58, 2)
assert_almost_equal(c, 1.00, 2)
assert_almost_equal(v, 0.73, 2)
def test_not_complete_and_not_homogeneous_labeling():
# neither complete nor homogeneous but not so bad either
h, c, v = homogeneity_completeness_v_measure([0, 0, 0, 1, 1, 1], [0, 1, 0, 1, 2, 2])
assert_almost_equal(h, 0.67, 2)
assert_almost_equal(c, 0.42, 2)
assert_almost_equal(v, 0.52, 2)
def test_beta_parameter():
# test for when beta passed to
# homogeneity_completeness_v_measure
# and v_measure_score
beta_test = 0.2
h_test = 0.67
c_test = 0.42
v_test = (1 + beta_test) * h_test * c_test / (beta_test * h_test + c_test)
h, c, v = homogeneity_completeness_v_measure(
[0, 0, 0, 1, 1, 1], [0, 1, 0, 1, 2, 2], beta=beta_test
)
assert_almost_equal(h, h_test, 2)
assert_almost_equal(c, c_test, 2)
assert_almost_equal(v, v_test, 2)
v = v_measure_score([0, 0, 0, 1, 1, 1], [0, 1, 0, 1, 2, 2], beta=beta_test)
assert_almost_equal(v, v_test, 2)
def test_non_consecutive_labels():
# regression tests for labels with gaps
h, c, v = homogeneity_completeness_v_measure([0, 0, 0, 2, 2, 2], [0, 1, 0, 1, 2, 2])
assert_almost_equal(h, 0.67, 2)
assert_almost_equal(c, 0.42, 2)
assert_almost_equal(v, 0.52, 2)
h, c, v = homogeneity_completeness_v_measure([0, 0, 0, 1, 1, 1], [0, 4, 0, 4, 2, 2])
assert_almost_equal(h, 0.67, 2)
assert_almost_equal(c, 0.42, 2)
assert_almost_equal(v, 0.52, 2)
ari_1 = adjusted_rand_score([0, 0, 0, 1, 1, 1], [0, 1, 0, 1, 2, 2])
ari_2 = adjusted_rand_score([0, 0, 0, 1, 1, 1], [0, 4, 0, 4, 2, 2])
assert_almost_equal(ari_1, 0.24, 2)
assert_almost_equal(ari_2, 0.24, 2)
ri_1 = rand_score([0, 0, 0, 1, 1, 1], [0, 1, 0, 1, 2, 2])
ri_2 = rand_score([0, 0, 0, 1, 1, 1], [0, 4, 0, 4, 2, 2])
assert_almost_equal(ri_1, 0.66, 2)
assert_almost_equal(ri_2, 0.66, 2)
def uniform_labelings_scores(score_func, n_samples, k_range, n_runs=10, seed=42):
# Compute score for random uniform cluster labelings
random_labels = np.random.RandomState(seed).randint
scores = np.zeros((len(k_range), n_runs))
for i, k in enumerate(k_range):
for j in range(n_runs):
labels_a = random_labels(low=0, high=k, size=n_samples)
labels_b = random_labels(low=0, high=k, size=n_samples)
scores[i, j] = score_func(labels_a, labels_b)
return scores
def test_adjustment_for_chance():
# Check that adjusted scores are almost zero on random labels
n_clusters_range = [2, 10, 50, 90]
n_samples = 100
n_runs = 10
scores = uniform_labelings_scores(
adjusted_rand_score, n_samples, n_clusters_range, n_runs
)
max_abs_scores = np.abs(scores).max(axis=1)
assert_array_almost_equal(max_abs_scores, [0.02, 0.03, 0.03, 0.02], 2)
def test_adjusted_mutual_info_score():
# Compute the Adjusted Mutual Information and test against known values
labels_a = np.array([1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3])
labels_b = np.array([1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 3, 1, 3, 3, 3, 2, 2])
# Mutual information
mi = mutual_info_score(labels_a, labels_b)
assert_almost_equal(mi, 0.41022, 5)
# with provided sparse contingency
C = contingency_matrix(labels_a, labels_b, sparse=True)
mi = mutual_info_score(labels_a, labels_b, contingency=C)
assert_almost_equal(mi, 0.41022, 5)
# with provided dense contingency
C = contingency_matrix(labels_a, labels_b)
mi = mutual_info_score(labels_a, labels_b, contingency=C)
assert_almost_equal(mi, 0.41022, 5)
# Expected mutual information
n_samples = C.sum()
emi = expected_mutual_information(C, n_samples)
assert_almost_equal(emi, 0.15042, 5)
# Adjusted mutual information
ami = adjusted_mutual_info_score(labels_a, labels_b)
assert_almost_equal(ami, 0.27821, 5)
ami = adjusted_mutual_info_score([1, 1, 2, 2], [2, 2, 3, 3])
assert ami == pytest.approx(1.0)
# Test with a very large array
a110 = np.array([list(labels_a) * 110]).flatten()
b110 = np.array([list(labels_b) * 110]).flatten()
ami = adjusted_mutual_info_score(a110, b110)
assert_almost_equal(ami, 0.38, 2)
def test_expected_mutual_info_overflow():
# Test for regression where contingency cell exceeds 2**16
# leading to overflow in np.outer, resulting in EMI > 1
assert expected_mutual_information(np.array([[70000]]), 70000) <= 1
def test_int_overflow_mutual_info_fowlkes_mallows_score():
# Test overflow in mutual_info_classif and fowlkes_mallows_score
x = np.array(
[1] * (52632 + 2529)
+ [2] * (14660 + 793)
+ [3] * (3271 + 204)
+ [4] * (814 + 39)
+ [5] * (316 + 20)
)
y = np.array(
[0] * 52632
+ [1] * 2529
+ [0] * 14660
+ [1] * 793
+ [0] * 3271
+ [1] * 204
+ [0] * 814
+ [1] * 39
+ [0] * 316
+ [1] * 20
)
assert_all_finite(mutual_info_score(x, y))
assert_all_finite(fowlkes_mallows_score(x, y))
def test_entropy():
ent = entropy([0, 0, 42.0])
assert_almost_equal(ent, 0.6365141, 5)
assert_almost_equal(entropy([]), 1)
assert entropy([1, 1, 1, 1]) == 0
def test_contingency_matrix():
labels_a = np.array([1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3])
labels_b = np.array([1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 3, 1, 3, 3, 3, 2, 2])
C = contingency_matrix(labels_a, labels_b)
C2 = np.histogram2d(labels_a, labels_b, bins=(np.arange(1, 5), np.arange(1, 5)))[0]
assert_array_almost_equal(C, C2)
C = contingency_matrix(labels_a, labels_b, eps=0.1)
assert_array_almost_equal(C, C2 + 0.1)
def test_contingency_matrix_sparse():
labels_a = np.array([1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3])
labels_b = np.array([1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 3, 1, 3, 3, 3, 2, 2])
C = contingency_matrix(labels_a, labels_b)
C_sparse = contingency_matrix(labels_a, labels_b, sparse=True).toarray()
assert_array_almost_equal(C, C_sparse)
with pytest.raises(ValueError, match="Cannot set 'eps' when sparse=True"):
contingency_matrix(labels_a, labels_b, eps=1e-10, sparse=True)
def test_exactly_zero_info_score():
# Check numerical stability when information is exactly zero
for i in np.logspace(1, 4, 4).astype(int):
labels_a, labels_b = (np.ones(i, dtype=int), np.arange(i, dtype=int))
assert normalized_mutual_info_score(labels_a, labels_b) == pytest.approx(0.0)
assert v_measure_score(labels_a, labels_b) == pytest.approx(0.0)
assert adjusted_mutual_info_score(labels_a, labels_b) == pytest.approx(0.0)
assert normalized_mutual_info_score(labels_a, labels_b) == pytest.approx(0.0)
for method in ["min", "geometric", "arithmetic", "max"]:
assert adjusted_mutual_info_score(
labels_a, labels_b, average_method=method
) == pytest.approx(0.0)
assert normalized_mutual_info_score(
labels_a, labels_b, average_method=method
) == pytest.approx(0.0)
def test_v_measure_and_mutual_information(seed=36):
# Check relation between v_measure, entropy and mutual information
for i in np.logspace(1, 4, 4).astype(int):
random_state = np.random.RandomState(seed)
labels_a, labels_b = (
random_state.randint(0, 10, i),
random_state.randint(0, 10, i),
)
assert_almost_equal(
v_measure_score(labels_a, labels_b),
2.0
* mutual_info_score(labels_a, labels_b)
/ (entropy(labels_a) + entropy(labels_b)),
0,
)
avg = "arithmetic"
assert_almost_equal(
v_measure_score(labels_a, labels_b),
normalized_mutual_info_score(labels_a, labels_b, average_method=avg),
)
def test_fowlkes_mallows_score():
# General case
score = fowlkes_mallows_score([0, 0, 0, 1, 1, 1], [0, 0, 1, 1, 2, 2])
assert_almost_equal(score, 4.0 / np.sqrt(12.0 * 6.0))
# Perfect match but where the label names changed
perfect_score = fowlkes_mallows_score([0, 0, 0, 1, 1, 1], [1, 1, 1, 0, 0, 0])
assert_almost_equal(perfect_score, 1.0)
# Worst case
worst_score = fowlkes_mallows_score([0, 0, 0, 0, 0, 0], [0, 1, 2, 3, 4, 5])
assert_almost_equal(worst_score, 0.0)
def test_fowlkes_mallows_score_properties():
# handcrafted example
labels_a = np.array([0, 0, 0, 1, 1, 2])
labels_b = np.array([1, 1, 2, 2, 0, 0])
expected = 1.0 / np.sqrt((1.0 + 3.0) * (1.0 + 2.0))
# FMI = TP / sqrt((TP + FP) * (TP + FN))
score_original = fowlkes_mallows_score(labels_a, labels_b)
assert_almost_equal(score_original, expected)
# symmetric property
score_symmetric = fowlkes_mallows_score(labels_b, labels_a)
assert_almost_equal(score_symmetric, expected)
# permutation property
score_permuted = fowlkes_mallows_score((labels_a + 1) % 3, labels_b)
assert_almost_equal(score_permuted, expected)
# symmetric and permutation(both together)
score_both = fowlkes_mallows_score(labels_b, (labels_a + 2) % 3)
assert_almost_equal(score_both, expected)
@pytest.mark.parametrize(
"labels_true, labels_pred",
[
(["a"] * 6, [1, 1, 0, 0, 1, 1]),
([1] * 6, [1, 1, 0, 0, 1, 1]),
([1, 1, 0, 0, 1, 1], ["a"] * 6),
([1, 1, 0, 0, 1, 1], [1] * 6),
(["a"] * 6, ["a"] * 6),
],
)
def test_mutual_info_score_positive_constant_label(labels_true, labels_pred):
# Check that MI = 0 when one or both labelling are constant
# non-regression test for #16355
assert mutual_info_score(labels_true, labels_pred) == 0
def test_check_clustering_error():
# Test warning message for continuous values
rng = np.random.RandomState(42)
noise = rng.rand(500)
wavelength = np.linspace(0.01, 1, 500) * 1e-6
msg = (
"Clustering metrics expects discrete values but received "
"continuous values for label, and continuous values for "
"target"
)
with pytest.warns(UserWarning, match=msg):
check_clusterings(wavelength, noise)
def test_pair_confusion_matrix_fully_dispersed():
# edge case: every element is its own cluster
N = 100
clustering1 = list(range(N))
clustering2 = clustering1
expected = np.array([[N * (N - 1), 0], [0, 0]])
assert_array_equal(pair_confusion_matrix(clustering1, clustering2), expected)
def test_pair_confusion_matrix_single_cluster():
# edge case: only one cluster
N = 100
clustering1 = np.zeros((N,))
clustering2 = clustering1
expected = np.array([[0, 0], [0, N * (N - 1)]])
assert_array_equal(pair_confusion_matrix(clustering1, clustering2), expected)
def test_pair_confusion_matrix():
# regular case: different non-trivial clusterings
n = 10
N = n**2
clustering1 = np.hstack([[i + 1] * n for i in range(n)])
clustering2 = np.hstack([[i + 1] * (n + 1) for i in range(n)])[:N]
# basic quadratic implementation
expected = np.zeros(shape=(2, 2), dtype=np.int64)
for i in range(len(clustering1)):
for j in range(len(clustering2)):
if i != j:
same_cluster_1 = int(clustering1[i] == clustering1[j])
same_cluster_2 = int(clustering2[i] == clustering2[j])
expected[same_cluster_1, same_cluster_2] += 1
assert_array_equal(pair_confusion_matrix(clustering1, clustering2), expected)
@pytest.mark.parametrize(
"clustering1, clustering2",
[(list(range(100)), list(range(100))), (np.zeros((100,)), np.zeros((100,)))],
)
def test_rand_score_edge_cases(clustering1, clustering2):
# edge case 1: every element is its own cluster
# edge case 2: only one cluster
assert_allclose(rand_score(clustering1, clustering2), 1.0)
def test_rand_score():
# regular case: different non-trivial clusterings
clustering1 = [0, 0, 0, 1, 1, 1]
clustering2 = [0, 1, 0, 1, 2, 2]
# pair confusion matrix
D11 = 2 * 2 # ordered pairs (1, 3), (5, 6)
D10 = 2 * 4 # ordered pairs (1, 2), (2, 3), (4, 5), (4, 6)
D01 = 2 * 1 # ordered pair (2, 4)
D00 = 5 * 6 - D11 - D01 - D10 # the remaining pairs
# rand score
expected_numerator = D00 + D11
expected_denominator = D00 + D01 + D10 + D11
expected = expected_numerator / expected_denominator
assert_allclose(rand_score(clustering1, clustering2), expected)
def test_adjusted_rand_score_overflow():
"""Check that large amount of data will not lead to overflow in
`adjusted_rand_score`.
Non-regression test for:
https://github.com/scikit-learn/scikit-learn/issues/20305
"""
rng = np.random.RandomState(0)
y_true = rng.randint(0, 2, 100_000, dtype=np.int8)
y_pred = rng.randint(0, 2, 100_000, dtype=np.int8)
with warnings.catch_warnings():
warnings.simplefilter("error", RuntimeWarning)
adjusted_rand_score(y_true, y_pred)
@pytest.mark.parametrize("average_method", ["min", "arithmetic", "geometric", "max"])
def test_normalized_mutual_info_score_bounded(average_method):
"""Check that nmi returns a score between 0 (included) and 1 (excluded
for non-perfect match)
Non-regression test for issue #13836
"""
labels1 = [0] * 469
labels2 = [1] + labels1[1:]
labels3 = [0, 1] + labels1[2:]
# labels1 is constant. The mutual info between labels1 and any other labelling is 0.
nmi = normalized_mutual_info_score(labels1, labels2, average_method=average_method)
assert nmi == 0
# non constant, non perfect matching labels
nmi = normalized_mutual_info_score(labels2, labels3, average_method=average_method)
assert 0 <= nmi < 1

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import warnings
import numpy as np
import scipy.sparse as sp
import pytest
from scipy.sparse import csr_matrix
from sklearn import datasets
from sklearn.utils._testing import assert_array_equal
from sklearn.metrics.cluster import silhouette_score
from sklearn.metrics.cluster import silhouette_samples
from sklearn.metrics import pairwise_distances
from sklearn.metrics.cluster import calinski_harabasz_score
from sklearn.metrics.cluster import davies_bouldin_score
def test_silhouette():
# Tests the Silhouette Coefficient.
dataset = datasets.load_iris()
X_dense = dataset.data
X_csr = csr_matrix(X_dense)
X_dok = sp.dok_matrix(X_dense)
X_lil = sp.lil_matrix(X_dense)
y = dataset.target
for X in [X_dense, X_csr, X_dok, X_lil]:
D = pairwise_distances(X, metric="euclidean")
# Given that the actual labels are used, we can assume that S would be
# positive.
score_precomputed = silhouette_score(D, y, metric="precomputed")
assert score_precomputed > 0
# Test without calculating D
score_euclidean = silhouette_score(X, y, metric="euclidean")
pytest.approx(score_precomputed, score_euclidean)
if X is X_dense:
score_dense_without_sampling = score_precomputed
else:
pytest.approx(score_euclidean, score_dense_without_sampling)
# Test with sampling
score_precomputed = silhouette_score(
D, y, metric="precomputed", sample_size=int(X.shape[0] / 2), random_state=0
)
score_euclidean = silhouette_score(
X, y, metric="euclidean", sample_size=int(X.shape[0] / 2), random_state=0
)
assert score_precomputed > 0
assert score_euclidean > 0
pytest.approx(score_euclidean, score_precomputed)
if X is X_dense:
score_dense_with_sampling = score_precomputed
else:
pytest.approx(score_euclidean, score_dense_with_sampling)
def test_cluster_size_1():
# Assert Silhouette Coefficient == 0 when there is 1 sample in a cluster
# (cluster 0). We also test the case where there are identical samples
# as the only members of a cluster (cluster 2). To our knowledge, this case
# is not discussed in reference material, and we choose for it a sample
# score of 1.
X = [[0.0], [1.0], [1.0], [2.0], [3.0], [3.0]]
labels = np.array([0, 1, 1, 1, 2, 2])
# Cluster 0: 1 sample -> score of 0 by Rousseeuw's convention
# Cluster 1: intra-cluster = [.5, .5, 1]
# inter-cluster = [1, 1, 1]
# silhouette = [.5, .5, 0]
# Cluster 2: intra-cluster = [0, 0]
# inter-cluster = [arbitrary, arbitrary]
# silhouette = [1., 1.]
silhouette = silhouette_score(X, labels)
assert not np.isnan(silhouette)
ss = silhouette_samples(X, labels)
assert_array_equal(ss, [0, 0.5, 0.5, 0, 1, 1])
def test_silhouette_paper_example():
# Explicitly check per-sample results against Rousseeuw (1987)
# Data from Table 1
lower = [
5.58,
7.00,
6.50,
7.08,
7.00,
3.83,
4.83,
5.08,
8.17,
5.83,
2.17,
5.75,
6.67,
6.92,
4.92,
6.42,
5.00,
5.58,
6.00,
4.67,
6.42,
3.42,
5.50,
6.42,
6.42,
5.00,
3.92,
6.17,
2.50,
4.92,
6.25,
7.33,
4.50,
2.25,
6.33,
2.75,
6.08,
6.67,
4.25,
2.67,
6.00,
6.17,
6.17,
6.92,
6.17,
5.25,
6.83,
4.50,
3.75,
5.75,
5.42,
6.08,
5.83,
6.67,
3.67,
4.75,
3.00,
6.08,
6.67,
5.00,
5.58,
4.83,
6.17,
5.67,
6.50,
6.92,
]
D = np.zeros((12, 12))
D[np.tril_indices(12, -1)] = lower
D += D.T
names = [
"BEL",
"BRA",
"CHI",
"CUB",
"EGY",
"FRA",
"IND",
"ISR",
"USA",
"USS",
"YUG",
"ZAI",
]
# Data from Figure 2
labels1 = [1, 1, 2, 2, 1, 1, 2, 1, 1, 2, 2, 1]
expected1 = {
"USA": 0.43,
"BEL": 0.39,
"FRA": 0.35,
"ISR": 0.30,
"BRA": 0.22,
"EGY": 0.20,
"ZAI": 0.19,
"CUB": 0.40,
"USS": 0.34,
"CHI": 0.33,
"YUG": 0.26,
"IND": -0.04,
}
score1 = 0.28
# Data from Figure 3
labels2 = [1, 2, 3, 3, 1, 1, 2, 1, 1, 3, 3, 2]
expected2 = {
"USA": 0.47,
"FRA": 0.44,
"BEL": 0.42,
"ISR": 0.37,
"EGY": 0.02,
"ZAI": 0.28,
"BRA": 0.25,
"IND": 0.17,
"CUB": 0.48,
"USS": 0.44,
"YUG": 0.31,
"CHI": 0.31,
}
score2 = 0.33
for labels, expected, score in [
(labels1, expected1, score1),
(labels2, expected2, score2),
]:
expected = [expected[name] for name in names]
# we check to 2dp because that's what's in the paper
pytest.approx(
expected,
silhouette_samples(D, np.array(labels), metric="precomputed"),
abs=1e-2,
)
pytest.approx(
score, silhouette_score(D, np.array(labels), metric="precomputed"), abs=1e-2
)
def test_correct_labelsize():
# Assert 1 < n_labels < n_samples
dataset = datasets.load_iris()
X = dataset.data
# n_labels = n_samples
y = np.arange(X.shape[0])
err_msg = (
r"Number of labels is %d\. Valid values are 2 "
r"to n_samples - 1 \(inclusive\)" % len(np.unique(y))
)
with pytest.raises(ValueError, match=err_msg):
silhouette_score(X, y)
# n_labels = 1
y = np.zeros(X.shape[0])
err_msg = (
r"Number of labels is %d\. Valid values are 2 "
r"to n_samples - 1 \(inclusive\)" % len(np.unique(y))
)
with pytest.raises(ValueError, match=err_msg):
silhouette_score(X, y)
def test_non_encoded_labels():
dataset = datasets.load_iris()
X = dataset.data
labels = dataset.target
assert silhouette_score(X, labels * 2 + 10) == silhouette_score(X, labels)
assert_array_equal(
silhouette_samples(X, labels * 2 + 10), silhouette_samples(X, labels)
)
def test_non_numpy_labels():
dataset = datasets.load_iris()
X = dataset.data
y = dataset.target
assert silhouette_score(list(X), list(y)) == silhouette_score(X, y)
@pytest.mark.parametrize("dtype", (np.float32, np.float64))
def test_silhouette_nonzero_diag(dtype):
# Make sure silhouette_samples requires diagonal to be zero.
# Non-regression test for #12178
# Construct a zero-diagonal matrix
dists = pairwise_distances(
np.array([[0.2, 0.1, 0.12, 1.34, 1.11, 1.6]], dtype=dtype).T
)
labels = [0, 0, 0, 1, 1, 1]
# small values on the diagonal are OK
dists[2][2] = np.finfo(dists.dtype).eps * 10
silhouette_samples(dists, labels, metric="precomputed")
# values bigger than eps * 100 are not
dists[2][2] = np.finfo(dists.dtype).eps * 1000
with pytest.raises(ValueError, match="contains non-zero"):
silhouette_samples(dists, labels, metric="precomputed")
def assert_raises_on_only_one_label(func):
"""Assert message when there is only one label"""
rng = np.random.RandomState(seed=0)
with pytest.raises(ValueError, match="Number of labels is"):
func(rng.rand(10, 2), np.zeros(10))
def assert_raises_on_all_points_same_cluster(func):
"""Assert message when all point are in different clusters"""
rng = np.random.RandomState(seed=0)
with pytest.raises(ValueError, match="Number of labels is"):
func(rng.rand(10, 2), np.arange(10))
def test_calinski_harabasz_score():
assert_raises_on_only_one_label(calinski_harabasz_score)
assert_raises_on_all_points_same_cluster(calinski_harabasz_score)
# Assert the value is 1. when all samples are equals
assert 1.0 == calinski_harabasz_score(np.ones((10, 2)), [0] * 5 + [1] * 5)
# Assert the value is 0. when all the mean cluster are equal
assert 0.0 == calinski_harabasz_score([[-1, -1], [1, 1]] * 10, [0] * 10 + [1] * 10)
# General case (with non numpy arrays)
X = (
[[0, 0], [1, 1]] * 5
+ [[3, 3], [4, 4]] * 5
+ [[0, 4], [1, 3]] * 5
+ [[3, 1], [4, 0]] * 5
)
labels = [0] * 10 + [1] * 10 + [2] * 10 + [3] * 10
pytest.approx(calinski_harabasz_score(X, labels), 45 * (40 - 4) / (5 * (4 - 1)))
def test_davies_bouldin_score():
assert_raises_on_only_one_label(davies_bouldin_score)
assert_raises_on_all_points_same_cluster(davies_bouldin_score)
# Assert the value is 0. when all samples are equals
assert davies_bouldin_score(np.ones((10, 2)), [0] * 5 + [1] * 5) == pytest.approx(
0.0
)
# Assert the value is 0. when all the mean cluster are equal
assert davies_bouldin_score(
[[-1, -1], [1, 1]] * 10, [0] * 10 + [1] * 10
) == pytest.approx(0.0)
# General case (with non numpy arrays)
X = (
[[0, 0], [1, 1]] * 5
+ [[3, 3], [4, 4]] * 5
+ [[0, 4], [1, 3]] * 5
+ [[3, 1], [4, 0]] * 5
)
labels = [0] * 10 + [1] * 10 + [2] * 10 + [3] * 10
pytest.approx(davies_bouldin_score(X, labels), 2 * np.sqrt(0.5) / 3)
# Ensure divide by zero warning is not raised in general case
with warnings.catch_warnings():
warnings.simplefilter("error", RuntimeWarning)
davies_bouldin_score(X, labels)
# General case - cluster have one sample
X = [[0, 0], [2, 2], [3, 3], [5, 5]]
labels = [0, 0, 1, 2]
pytest.approx(davies_bouldin_score(X, labels), (5.0 / 4) / 3)
def test_silhouette_score_integer_precomputed():
"""Check that silhouette_score works for precomputed metrics that are integers.
Non-regression test for #22107.
"""
result = silhouette_score(
[[0, 1, 2], [1, 0, 1], [2, 1, 0]], [0, 0, 1], metric="precomputed"
)
assert result == pytest.approx(1 / 6)
# non-zero on diagonal for ints raises an error
with pytest.raises(ValueError, match="contains non-zero"):
silhouette_score(
[[1, 1, 2], [1, 0, 1], [2, 1, 0]], [0, 0, 1], metric="precomputed"
)

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import os
import numpy as np
from numpy.distutils.misc_util import Configuration
def configuration(parent_package="", top_path=None):
config = Configuration("metrics", parent_package, top_path)
libraries = []
if os.name == "posix":
libraries.append("m")
config.add_subpackage("_plot")
config.add_subpackage("_plot.tests")
config.add_subpackage("cluster")
config.add_extension(
"_pairwise_fast", sources=["_pairwise_fast.pyx"], libraries=libraries
)
config.add_extension(
"_dist_metrics",
sources=["_dist_metrics.pyx"],
include_dirs=[np.get_include(), os.path.join(np.get_include(), "numpy")],
libraries=libraries,
)
config.add_extension(
"_pairwise_distances_reduction",
sources=["_pairwise_distances_reduction.pyx"],
include_dirs=[np.get_include(), os.path.join(np.get_include(), "numpy")],
language="c++",
libraries=libraries,
extra_compile_args=["-std=c++11"],
)
config.add_subpackage("tests")
return config
if __name__ == "__main__":
from numpy.distutils.core import setup
setup(**configuration().todict())

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import itertools
import pickle
import copy
import numpy as np
from numpy.testing import assert_array_almost_equal
import pytest
import scipy.sparse as sp
from scipy.spatial.distance import cdist
from sklearn.metrics import DistanceMetric
from sklearn.metrics._dist_metrics import BOOL_METRICS
from sklearn.utils import check_random_state
from sklearn.utils._testing import create_memmap_backed_data
from sklearn.utils.fixes import sp_version, parse_version
def dist_func(x1, x2, p):
return np.sum((x1 - x2) ** p) ** (1.0 / p)
rng = check_random_state(0)
d = 4
n1 = 20
n2 = 25
X1 = rng.random_sample((n1, d)).astype("float64", copy=False)
X2 = rng.random_sample((n2, d)).astype("float64", copy=False)
[X1_mmap, X2_mmap] = create_memmap_backed_data([X1, X2])
# make boolean arrays: ones and zeros
X1_bool = X1.round(0)
X2_bool = X2.round(0)
[X1_bool_mmap, X2_bool_mmap] = create_memmap_backed_data([X1_bool, X2_bool])
V = rng.random_sample((d, d))
VI = np.dot(V, V.T)
METRICS_DEFAULT_PARAMS = [
("euclidean", {}),
("cityblock", {}),
("minkowski", dict(p=(1, 1.5, 2, 3))),
("chebyshev", {}),
("seuclidean", dict(V=(rng.random_sample(d),))),
("mahalanobis", dict(VI=(VI,))),
("hamming", {}),
("canberra", {}),
("braycurtis", {}),
]
if sp_version >= parse_version("1.8.0.dev0"):
# Starting from scipy 1.8.0.dev0, minkowski now accepts w, the weighting
# parameter directly and using it is preferred over using wminkowski.
METRICS_DEFAULT_PARAMS.append(
("minkowski", dict(p=(1, 1.5, 3), w=(rng.random_sample(d),))),
)
else:
# For previous versions of scipy, this was possible through a dedicated
# metric (deprecated in 1.6 and removed in 1.8).
METRICS_DEFAULT_PARAMS.append(
("wminkowski", dict(p=(1, 1.5, 3), w=(rng.random_sample(d),))),
)
def check_cdist(metric, kwargs, X1, X2):
if metric == "wminkowski":
# wminkoski is deprecated in SciPy 1.6.0 and removed in 1.8.0
WarningToExpect = None
if sp_version >= parse_version("1.6.0"):
WarningToExpect = DeprecationWarning
with pytest.warns(WarningToExpect):
D_scipy_cdist = cdist(X1, X2, metric, **kwargs)
else:
D_scipy_cdist = cdist(X1, X2, metric, **kwargs)
dm = DistanceMetric.get_metric(metric, **kwargs)
D_sklearn = dm.pairwise(X1, X2)
assert_array_almost_equal(D_sklearn, D_scipy_cdist)
# TODO: Remove filterwarnings in 1.3 when wminkowski is removed
@pytest.mark.filterwarnings("ignore:WMinkowskiDistance:FutureWarning:sklearn")
@pytest.mark.parametrize("metric_param_grid", METRICS_DEFAULT_PARAMS)
@pytest.mark.parametrize("X1, X2", [(X1, X2), (X1_mmap, X2_mmap)])
def test_cdist(metric_param_grid, X1, X2):
metric, param_grid = metric_param_grid
keys = param_grid.keys()
for vals in itertools.product(*param_grid.values()):
kwargs = dict(zip(keys, vals))
if metric == "mahalanobis":
# See: https://github.com/scipy/scipy/issues/13861
# Possibly caused by: https://github.com/joblib/joblib/issues/563
pytest.xfail(
"scipy#13861: cdist with 'mahalanobis' fails on joblib memmap data"
)
check_cdist(metric, kwargs, X1, X2)
@pytest.mark.parametrize("metric", BOOL_METRICS)
@pytest.mark.parametrize(
"X1_bool, X2_bool", [(X1_bool, X2_bool), (X1_bool_mmap, X2_bool_mmap)]
)
def test_cdist_bool_metric(metric, X1_bool, X2_bool):
D_true = cdist(X1_bool, X2_bool, metric)
check_cdist_bool(metric, D_true)
def check_cdist_bool(metric, D_true):
dm = DistanceMetric.get_metric(metric)
D12 = dm.pairwise(X1_bool, X2_bool)
assert_array_almost_equal(D12, D_true)
# TODO: Remove filterwarnings in 1.3 when wminkowski is removed
@pytest.mark.filterwarnings("ignore:WMinkowskiDistance:FutureWarning:sklearn")
@pytest.mark.parametrize("metric_param_grid", METRICS_DEFAULT_PARAMS)
@pytest.mark.parametrize("X1, X2", [(X1, X2), (X1_mmap, X2_mmap)])
def test_pdist(metric_param_grid, X1, X2):
metric, param_grid = metric_param_grid
keys = param_grid.keys()
for vals in itertools.product(*param_grid.values()):
kwargs = dict(zip(keys, vals))
if metric == "mahalanobis":
# See: https://github.com/scipy/scipy/issues/13861
pytest.xfail("scipy#13861: pdist with 'mahalanobis' fails onmemmap data")
elif metric == "wminkowski":
if sp_version >= parse_version("1.8.0"):
pytest.skip("wminkowski will be removed in SciPy 1.8.0")
# wminkoski is deprecated in SciPy 1.6.0 and removed in 1.8.0
ExceptionToAssert = None
if sp_version >= parse_version("1.6.0"):
ExceptionToAssert = DeprecationWarning
with pytest.warns(ExceptionToAssert):
D_true = cdist(X1, X1, metric, **kwargs)
else:
D_true = cdist(X1, X1, metric, **kwargs)
check_pdist(metric, kwargs, D_true)
@pytest.mark.parametrize("metric", BOOL_METRICS)
@pytest.mark.parametrize("X1_bool", [X1_bool, X1_bool_mmap])
def test_pdist_bool_metrics(metric, X1_bool):
D_true = cdist(X1_bool, X1_bool, metric)
check_pdist_bool(metric, D_true)
def check_pdist(metric, kwargs, D_true):
dm = DistanceMetric.get_metric(metric, **kwargs)
D12 = dm.pairwise(X1)
assert_array_almost_equal(D12, D_true)
def check_pdist_bool(metric, D_true):
dm = DistanceMetric.get_metric(metric)
D12 = dm.pairwise(X1_bool)
# Based on https://github.com/scipy/scipy/pull/7373
# When comparing two all-zero vectors, scipy>=1.2.0 jaccard metric
# was changed to return 0, instead of nan.
if metric == "jaccard" and sp_version < parse_version("1.2.0"):
D_true[np.isnan(D_true)] = 0
assert_array_almost_equal(D12, D_true)
# TODO: Remove filterwarnings in 1.3 when wminkowski is removed
@pytest.mark.filterwarnings("ignore:WMinkowskiDistance:FutureWarning:sklearn")
@pytest.mark.parametrize("writable_kwargs", [True, False])
@pytest.mark.parametrize("metric_param_grid", METRICS_DEFAULT_PARAMS)
def test_pickle(writable_kwargs, metric_param_grid):
metric, param_grid = metric_param_grid
keys = param_grid.keys()
for vals in itertools.product(*param_grid.values()):
if any(isinstance(val, np.ndarray) for val in vals):
vals = copy.deepcopy(vals)
for val in vals:
if isinstance(val, np.ndarray):
val.setflags(write=writable_kwargs)
kwargs = dict(zip(keys, vals))
check_pickle(metric, kwargs)
# TODO: Remove filterwarnings in 1.3 when wminkowski is removed
@pytest.mark.filterwarnings("ignore:WMinkowskiDistance:FutureWarning:sklearn")
@pytest.mark.parametrize("metric", BOOL_METRICS)
@pytest.mark.parametrize("X1_bool", [X1_bool, X1_bool_mmap])
def test_pickle_bool_metrics(metric, X1_bool):
dm = DistanceMetric.get_metric(metric)
D1 = dm.pairwise(X1_bool)
dm2 = pickle.loads(pickle.dumps(dm))
D2 = dm2.pairwise(X1_bool)
assert_array_almost_equal(D1, D2)
def check_pickle(metric, kwargs):
dm = DistanceMetric.get_metric(metric, **kwargs)
D1 = dm.pairwise(X1)
dm2 = pickle.loads(pickle.dumps(dm))
D2 = dm2.pairwise(X1)
assert_array_almost_equal(D1, D2)
def test_haversine_metric():
def haversine_slow(x1, x2):
return 2 * np.arcsin(
np.sqrt(
np.sin(0.5 * (x1[0] - x2[0])) ** 2
+ np.cos(x1[0]) * np.cos(x2[0]) * np.sin(0.5 * (x1[1] - x2[1])) ** 2
)
)
X = np.random.random((10, 2))
haversine = DistanceMetric.get_metric("haversine")
D1 = haversine.pairwise(X)
D2 = np.zeros_like(D1)
for i, x1 in enumerate(X):
for j, x2 in enumerate(X):
D2[i, j] = haversine_slow(x1, x2)
assert_array_almost_equal(D1, D2)
assert_array_almost_equal(haversine.dist_to_rdist(D1), np.sin(0.5 * D2) ** 2)
def test_pyfunc_metric():
X = np.random.random((10, 3))
euclidean = DistanceMetric.get_metric("euclidean")
pyfunc = DistanceMetric.get_metric("pyfunc", func=dist_func, p=2)
# Check if both callable metric and predefined metric initialized
# DistanceMetric object is picklable
euclidean_pkl = pickle.loads(pickle.dumps(euclidean))
pyfunc_pkl = pickle.loads(pickle.dumps(pyfunc))
D1 = euclidean.pairwise(X)
D2 = pyfunc.pairwise(X)
D1_pkl = euclidean_pkl.pairwise(X)
D2_pkl = pyfunc_pkl.pairwise(X)
assert_array_almost_equal(D1, D2)
assert_array_almost_equal(D1_pkl, D2_pkl)
def test_input_data_size():
# Regression test for #6288
# Previously, a metric requiring a particular input dimension would fail
def custom_metric(x, y):
assert x.shape[0] == 3
return np.sum((x - y) ** 2)
rng = check_random_state(0)
X = rng.rand(10, 3)
pyfunc = DistanceMetric.get_metric("pyfunc", func=custom_metric)
eucl = DistanceMetric.get_metric("euclidean")
assert_array_almost_equal(pyfunc.pairwise(X), eucl.pairwise(X) ** 2)
# TODO: Remove filterwarnings in 1.3 when wminkowski is removed
@pytest.mark.filterwarnings("ignore:WMinkowskiDistance:FutureWarning:sklearn")
def test_readonly_kwargs():
# Non-regression test for:
# https://github.com/scikit-learn/scikit-learn/issues/21685
rng = check_random_state(0)
weights = rng.rand(100)
VI = rng.rand(10, 10)
weights.setflags(write=False)
VI.setflags(write=False)
# Those distances metrics have to support readonly buffers.
DistanceMetric.get_metric("seuclidean", V=weights)
DistanceMetric.get_metric("wminkowski", p=1, w=weights)
DistanceMetric.get_metric("mahalanobis", VI=VI)
@pytest.mark.parametrize(
"w, err_type, err_msg",
[
(np.array([1, 1.5, -13]), ValueError, "w cannot contain negative weights"),
(np.array([1, 1.5, np.nan]), ValueError, "w contains NaN"),
(
sp.csr_matrix([1, 1.5, 1]),
TypeError,
"A sparse matrix was passed, but dense data is required",
),
(np.array(["a", "b", "c"]), ValueError, "could not convert string to float"),
(np.array([]), ValueError, "a minimum of 1 is required"),
],
)
def test_minkowski_metric_validate_weights_values(w, err_type, err_msg):
with pytest.raises(err_type, match=err_msg):
DistanceMetric.get_metric("minkowski", p=3, w=w)
def test_minkowski_metric_validate_weights_size():
w2 = rng.random_sample(d + 1)
dm = DistanceMetric.get_metric("minkowski", p=3, w=w2)
msg = (
"MinkowskiDistance: the size of w must match "
f"the number of features \\({X1.shape[1]}\\). "
f"Currently len\\(w\\)={w2.shape[0]}."
)
with pytest.raises(ValueError, match=msg):
dm.pairwise(X1, X2)
# TODO: Remove in 1.3 when wminkowski is removed
def test_wminkowski_deprecated():
w = rng.random_sample(d)
msg = "WMinkowskiDistance is deprecated in version 1.1"
with pytest.warns(FutureWarning, match=msg):
DistanceMetric.get_metric("wminkowski", p=3, w=w)
# TODO: Remove in 1.3 when wminkowski is removed
@pytest.mark.filterwarnings("ignore:WMinkowskiDistance:FutureWarning:sklearn")
@pytest.mark.parametrize("p", [1, 1.5, 3])
def test_wminkowski_minkowski_equivalence(p):
w = rng.random_sample(d)
# Weights are rescaled for consistency w.r.t scipy 1.8 refactoring of 'minkowski'
dm_wmks = DistanceMetric.get_metric("wminkowski", p=p, w=(w) ** (1 / p))
dm_mks = DistanceMetric.get_metric("minkowski", p=p, w=w)
D_wmks = dm_wmks.pairwise(X1, X2)
D_mks = dm_mks.pairwise(X1, X2)
assert_array_almost_equal(D_wmks, D_mks)

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import numpy as np
import pytest
import threadpoolctl
from numpy.testing import assert_array_equal, assert_allclose
from scipy.sparse import csr_matrix
from scipy.spatial.distance import cdist
from sklearn.metrics._pairwise_distances_reduction import (
PairwiseDistancesReduction,
PairwiseDistancesArgKmin,
PairwiseDistancesRadiusNeighborhood,
_sqeuclidean_row_norms,
)
from sklearn.metrics import euclidean_distances
from sklearn.utils.fixes import sp_version, parse_version
# Common supported metric between scipy.spatial.distance.cdist
# and PairwiseDistancesReduction.
# This allows constructing tests to check consistency of results
# of concrete PairwiseDistancesReduction on some metrics using APIs
# from scipy and numpy.
CDIST_PAIRWISE_DISTANCES_REDUCTION_COMMON_METRICS = [
"braycurtis",
"canberra",
"chebyshev",
"cityblock",
"euclidean",
"minkowski",
"seuclidean",
]
def _get_metric_params_list(metric: str, n_features: int, seed: int = 1):
"""Return list of dummy DistanceMetric kwargs for tests."""
# Distinguishing on cases not to compute unneeded datastructures.
rng = np.random.RandomState(seed)
if metric == "minkowski":
minkowski_kwargs = [dict(p=1.5), dict(p=2), dict(p=3), dict(p=np.inf)]
if sp_version >= parse_version("1.8.0.dev0"):
# TODO: remove the test once we no longer support scipy < 1.8.0.
# Recent scipy versions accept weights in the Minkowski metric directly:
# type: ignore
minkowski_kwargs.append(dict(p=3, w=rng.rand(n_features)))
return minkowski_kwargs
# TODO: remove this case for "wminkowski" once we no longer support scipy < 1.8.0.
if metric == "wminkowski":
weights = rng.random_sample(n_features)
weights /= weights.sum()
wminkowski_kwargs = [dict(p=1.5, w=weights)]
if sp_version < parse_version("1.8.0.dev0"):
# wminkowski was removed in scipy 1.8.0 but should work for previous
# versions.
wminkowski_kwargs.append(dict(p=3, w=rng.rand(n_features)))
return wminkowski_kwargs
if metric == "seuclidean":
return [dict(V=rng.rand(n_features))]
# Case of: "euclidean", "manhattan", "chebyshev", "haversine" or any other metric.
# In those cases, no kwargs is needed.
return [{}]
def assert_argkmin_results_equality(ref_dist, dist, ref_indices, indices):
assert_array_equal(
ref_indices,
indices,
err_msg="Query vectors have different neighbors' indices",
)
assert_allclose(
ref_dist,
dist,
err_msg="Query vectors have different neighbors' distances",
rtol=1e-7,
)
def assert_radius_neighborhood_results_equality(ref_dist, dist, ref_indices, indices):
# We get arrays of arrays and we need to check for individual pairs
for i in range(ref_dist.shape[0]):
assert_array_equal(
ref_indices[i],
indices[i],
err_msg=f"Query vector #{i} has different neighbors' indices",
)
assert_allclose(
ref_dist[i],
dist[i],
err_msg=f"Query vector #{i} has different neighbors' distances",
rtol=1e-7,
)
ASSERT_RESULT = {
PairwiseDistancesArgKmin: assert_argkmin_results_equality,
PairwiseDistancesRadiusNeighborhood: assert_radius_neighborhood_results_equality,
}
def test_pairwise_distances_reduction_is_usable_for():
rng = np.random.RandomState(0)
X = rng.rand(100, 10)
Y = rng.rand(100, 10)
metric = "euclidean"
assert PairwiseDistancesReduction.is_usable_for(X, Y, metric)
assert not PairwiseDistancesReduction.is_usable_for(
X.astype(np.int64), Y.astype(np.int64), metric
)
assert not PairwiseDistancesReduction.is_usable_for(X, Y, metric="pyfunc")
# TODO: remove once 32 bits datasets are supported
assert not PairwiseDistancesReduction.is_usable_for(X.astype(np.float32), Y, metric)
assert not PairwiseDistancesReduction.is_usable_for(X, Y.astype(np.int32), metric)
# TODO: remove once sparse matrices are supported
assert not PairwiseDistancesReduction.is_usable_for(csr_matrix(X), Y, metric)
assert not PairwiseDistancesReduction.is_usable_for(X, csr_matrix(Y), metric)
def test_argkmin_factory_method_wrong_usages():
rng = np.random.RandomState(1)
X = rng.rand(100, 10)
Y = rng.rand(100, 10)
k = 5
metric = "euclidean"
msg = (
"Only 64bit float datasets are supported at this time, "
"got: X.dtype=float32 and Y.dtype=float64"
)
with pytest.raises(ValueError, match=msg):
PairwiseDistancesArgKmin.compute(
X=X.astype(np.float32), Y=Y, k=k, metric=metric
)
msg = (
"Only 64bit float datasets are supported at this time, "
"got: X.dtype=float64 and Y.dtype=int32"
)
with pytest.raises(ValueError, match=msg):
PairwiseDistancesArgKmin.compute(X=X, Y=Y.astype(np.int32), k=k, metric=metric)
with pytest.raises(ValueError, match="k == -1, must be >= 1."):
PairwiseDistancesArgKmin.compute(X=X, Y=Y, k=-1, metric=metric)
with pytest.raises(ValueError, match="k == 0, must be >= 1."):
PairwiseDistancesArgKmin.compute(X=X, Y=Y, k=0, metric=metric)
with pytest.raises(ValueError, match="Unrecognized metric"):
PairwiseDistancesArgKmin.compute(X=X, Y=Y, k=k, metric="wrong metric")
with pytest.raises(
ValueError, match=r"Buffer has wrong number of dimensions \(expected 2, got 1\)"
):
PairwiseDistancesArgKmin.compute(
X=np.array([1.0, 2.0]), Y=Y, k=k, metric=metric
)
with pytest.raises(ValueError, match="ndarray is not C-contiguous"):
PairwiseDistancesArgKmin.compute(
X=np.asfortranarray(X), Y=Y, k=k, metric=metric
)
unused_metric_kwargs = {"p": 3}
message = (
r"Some metric_kwargs have been passed \({'p': 3}\) but aren't usable for this"
r" case \("
r"FastEuclideanPairwiseDistancesArgKmin\) and will be ignored."
)
with pytest.warns(UserWarning, match=message):
PairwiseDistancesArgKmin.compute(
X=X, Y=Y, k=k, metric=metric, metric_kwargs=unused_metric_kwargs
)
def test_radius_neighborhood_factory_method_wrong_usages():
rng = np.random.RandomState(1)
X = rng.rand(100, 10)
Y = rng.rand(100, 10)
radius = 5
metric = "euclidean"
with pytest.raises(
ValueError,
match=(
"Only 64bit float datasets are supported at this time, "
"got: X.dtype=float32 and Y.dtype=float64"
),
):
PairwiseDistancesRadiusNeighborhood.compute(
X=X.astype(np.float32), Y=Y, radius=radius, metric=metric
)
with pytest.raises(
ValueError,
match=(
"Only 64bit float datasets are supported at this time, "
"got: X.dtype=float64 and Y.dtype=int32"
),
):
PairwiseDistancesRadiusNeighborhood.compute(
X=X, Y=Y.astype(np.int32), radius=radius, metric=metric
)
with pytest.raises(ValueError, match="radius == -1.0, must be >= 0."):
PairwiseDistancesRadiusNeighborhood.compute(X=X, Y=Y, radius=-1, metric=metric)
with pytest.raises(ValueError, match="Unrecognized metric"):
PairwiseDistancesRadiusNeighborhood.compute(
X=X, Y=Y, radius=radius, metric="wrong metric"
)
with pytest.raises(
ValueError, match=r"Buffer has wrong number of dimensions \(expected 2, got 1\)"
):
PairwiseDistancesRadiusNeighborhood.compute(
X=np.array([1.0, 2.0]), Y=Y, radius=radius, metric=metric
)
with pytest.raises(ValueError, match="ndarray is not C-contiguous"):
PairwiseDistancesRadiusNeighborhood.compute(
X=np.asfortranarray(X), Y=Y, radius=radius, metric=metric
)
unused_metric_kwargs = {"p": 3}
message = (
r"Some metric_kwargs have been passed \({'p': 3}\) but aren't usable for this"
r" case \(FastEuclideanPairwiseDistancesRadiusNeighborhood\) and will be"
r" ignored."
)
with pytest.warns(UserWarning, match=message):
PairwiseDistancesRadiusNeighborhood.compute(
X=X, Y=Y, radius=radius, metric=metric, metric_kwargs=unused_metric_kwargs
)
@pytest.mark.parametrize("n_samples", [100, 1000])
@pytest.mark.parametrize("chunk_size", [50, 512, 1024])
@pytest.mark.parametrize(
"PairwiseDistancesReduction",
[PairwiseDistancesArgKmin, PairwiseDistancesRadiusNeighborhood],
)
def test_chunk_size_agnosticism(
global_random_seed,
PairwiseDistancesReduction,
n_samples,
chunk_size,
n_features=100,
dtype=np.float64,
):
# Results should not depend on the chunk size
rng = np.random.RandomState(global_random_seed)
spread = 100
X = rng.rand(n_samples, n_features).astype(dtype) * spread
Y = rng.rand(n_samples, n_features).astype(dtype) * spread
parameter = (
10
if PairwiseDistancesReduction is PairwiseDistancesArgKmin
# Scaling the radius slightly with the numbers of dimensions
else 10 ** np.log(n_features)
)
ref_dist, ref_indices = PairwiseDistancesReduction.compute(
X,
Y,
parameter,
return_distance=True,
)
dist, indices = PairwiseDistancesReduction.compute(
X,
Y,
parameter,
chunk_size=chunk_size,
return_distance=True,
)
ASSERT_RESULT[PairwiseDistancesReduction](ref_dist, dist, ref_indices, indices)
@pytest.mark.parametrize("n_samples", [100, 1000])
@pytest.mark.parametrize("chunk_size", [50, 512, 1024])
@pytest.mark.parametrize(
"PairwiseDistancesReduction",
[PairwiseDistancesArgKmin, PairwiseDistancesRadiusNeighborhood],
)
def test_n_threads_agnosticism(
global_random_seed,
PairwiseDistancesReduction,
n_samples,
chunk_size,
n_features=100,
dtype=np.float64,
):
# Results should not depend on the number of threads
rng = np.random.RandomState(global_random_seed)
spread = 100
X = rng.rand(n_samples, n_features).astype(dtype) * spread
Y = rng.rand(n_samples, n_features).astype(dtype) * spread
parameter = (
10
if PairwiseDistancesReduction is PairwiseDistancesArgKmin
# Scaling the radius slightly with the numbers of dimensions
else 10 ** np.log(n_features)
)
ref_dist, ref_indices = PairwiseDistancesReduction.compute(
X,
Y,
parameter,
return_distance=True,
)
with threadpoolctl.threadpool_limits(limits=1, user_api="openmp"):
dist, indices = PairwiseDistancesReduction.compute(
X, Y, parameter, return_distance=True
)
ASSERT_RESULT[PairwiseDistancesReduction](ref_dist, dist, ref_indices, indices)
# TODO: Remove filterwarnings in 1.3 when wminkowski is removed
@pytest.mark.filterwarnings("ignore:WMinkowskiDistance:FutureWarning:sklearn")
@pytest.mark.parametrize("n_samples", [100, 1000])
@pytest.mark.parametrize("metric", PairwiseDistancesReduction.valid_metrics())
@pytest.mark.parametrize(
"PairwiseDistancesReduction",
[PairwiseDistancesArgKmin, PairwiseDistancesRadiusNeighborhood],
)
def test_strategies_consistency(
global_random_seed,
PairwiseDistancesReduction,
metric,
n_samples,
n_features=10,
dtype=np.float64,
):
rng = np.random.RandomState(global_random_seed)
spread = 100
X = rng.rand(n_samples, n_features).astype(dtype) * spread
Y = rng.rand(n_samples, n_features).astype(dtype) * spread
# Haversine distance only accepts 2D data
if metric == "haversine":
X = np.ascontiguousarray(X[:, :2])
Y = np.ascontiguousarray(Y[:, :2])
parameter = (
10
if PairwiseDistancesReduction is PairwiseDistancesArgKmin
# Scaling the radius slightly with the numbers of dimensions
else 10 ** np.log(n_features)
)
dist_par_X, indices_par_X = PairwiseDistancesReduction.compute(
X,
Y,
parameter,
metric=metric,
# Taking the first
metric_kwargs=_get_metric_params_list(
metric, n_features, seed=global_random_seed
)[0],
# To be sure to use parallelization
chunk_size=n_samples // 4,
strategy="parallel_on_X",
return_distance=True,
)
dist_par_Y, indices_par_Y = PairwiseDistancesReduction.compute(
X,
Y,
parameter,
metric=metric,
# Taking the first
metric_kwargs=_get_metric_params_list(
metric, n_features, seed=global_random_seed
)[0],
# To be sure to use parallelization
chunk_size=n_samples // 4,
strategy="parallel_on_Y",
return_distance=True,
)
ASSERT_RESULT[PairwiseDistancesReduction](
dist_par_X,
dist_par_Y,
indices_par_X,
indices_par_Y,
)
# "Concrete PairwiseDistancesReductions"-specific tests
# TODO: Remove filterwarnings in 1.3 when wminkowski is removed
@pytest.mark.filterwarnings("ignore:WMinkowskiDistance:FutureWarning:sklearn")
@pytest.mark.parametrize("n_features", [50, 500])
@pytest.mark.parametrize("translation", [0, 1e6])
@pytest.mark.parametrize("metric", CDIST_PAIRWISE_DISTANCES_REDUCTION_COMMON_METRICS)
@pytest.mark.parametrize("strategy", ("parallel_on_X", "parallel_on_Y"))
def test_pairwise_distances_argkmin(
global_random_seed,
n_features,
translation,
metric,
strategy,
n_samples=100,
k=10,
dtype=np.float64,
):
rng = np.random.RandomState(global_random_seed)
spread = 1000
X = translation + rng.rand(n_samples, n_features).astype(dtype) * spread
Y = translation + rng.rand(n_samples, n_features).astype(dtype) * spread
# Haversine distance only accepts 2D data
if metric == "haversine":
X = np.ascontiguousarray(X[:, :2])
Y = np.ascontiguousarray(Y[:, :2])
metric_kwargs = _get_metric_params_list(metric, n_features)[0]
# Reference for argkmin results
if metric == "euclidean":
# Compare to scikit-learn GEMM optimized implementation
dist_matrix = euclidean_distances(X, Y)
else:
dist_matrix = cdist(X, Y, metric=metric, **metric_kwargs)
# Taking argkmin (indices of the k smallest values)
argkmin_indices_ref = np.argsort(dist_matrix, axis=1)[:, :k]
# Getting the associated distances
argkmin_distances_ref = np.zeros(argkmin_indices_ref.shape, dtype=np.float64)
for row_idx in range(argkmin_indices_ref.shape[0]):
argkmin_distances_ref[row_idx] = dist_matrix[
row_idx, argkmin_indices_ref[row_idx]
]
argkmin_distances, argkmin_indices = PairwiseDistancesArgKmin.compute(
X,
Y,
k,
metric=metric,
metric_kwargs=metric_kwargs,
return_distance=True,
# So as to have more than a chunk, forcing parallelism.
chunk_size=n_samples // 4,
strategy=strategy,
)
ASSERT_RESULT[PairwiseDistancesArgKmin](
argkmin_distances, argkmin_distances_ref, argkmin_indices, argkmin_indices_ref
)
# TODO: Remove filterwarnings in 1.3 when wminkowski is removed
@pytest.mark.filterwarnings("ignore:WMinkowskiDistance:FutureWarning:sklearn")
@pytest.mark.parametrize("n_features", [50, 500])
@pytest.mark.parametrize("translation", [0, 1e6])
@pytest.mark.parametrize("metric", CDIST_PAIRWISE_DISTANCES_REDUCTION_COMMON_METRICS)
@pytest.mark.parametrize("strategy", ("parallel_on_X", "parallel_on_Y"))
def test_pairwise_distances_radius_neighbors(
global_random_seed,
n_features,
translation,
metric,
strategy,
n_samples=100,
dtype=np.float64,
):
rng = np.random.RandomState(global_random_seed)
spread = 1000
radius = spread * np.log(n_features)
X = translation + rng.rand(n_samples, n_features).astype(dtype) * spread
Y = translation + rng.rand(n_samples, n_features).astype(dtype) * spread
metric_kwargs = _get_metric_params_list(
metric, n_features, seed=global_random_seed
)[0]
# Reference for argkmin results
if metric == "euclidean":
# Compare to scikit-learn GEMM optimized implementation
dist_matrix = euclidean_distances(X, Y)
else:
dist_matrix = cdist(X, Y, metric=metric, **metric_kwargs)
# Getting the neighbors for a given radius
neigh_indices_ref = []
neigh_distances_ref = []
for row in dist_matrix:
ind = np.arange(row.shape[0])[row <= radius]
dist = row[ind]
sort = np.argsort(dist)
ind, dist = ind[sort], dist[sort]
neigh_indices_ref.append(ind)
neigh_distances_ref.append(dist)
neigh_indices_ref = np.array(neigh_indices_ref)
neigh_distances_ref = np.array(neigh_distances_ref)
neigh_distances, neigh_indices = PairwiseDistancesRadiusNeighborhood.compute(
X,
Y,
radius,
metric=metric,
metric_kwargs=metric_kwargs,
return_distance=True,
# So as to have more than a chunk, forcing parallelism.
chunk_size=n_samples // 4,
strategy=strategy,
sort_results=True,
)
ASSERT_RESULT[PairwiseDistancesRadiusNeighborhood](
neigh_distances, neigh_distances_ref, neigh_indices, neigh_indices_ref
)
@pytest.mark.parametrize("n_samples", [100, 1000])
@pytest.mark.parametrize("n_features", [5, 10, 100])
@pytest.mark.parametrize("num_threads", [1, 2, 8])
def test_sqeuclidean_row_norms(
global_random_seed,
n_samples,
n_features,
num_threads,
dtype=np.float64,
):
rng = np.random.RandomState(global_random_seed)
spread = 100
X = rng.rand(n_samples, n_features).astype(dtype) * spread
sq_row_norm_reference = np.linalg.norm(X, axis=1) ** 2
sq_row_norm = np.asarray(_sqeuclidean_row_norms(X, num_threads=num_threads))
assert_allclose(sq_row_norm_reference, sq_row_norm)

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import numpy as np
from scipy import optimize
from numpy.testing import assert_allclose
from scipy.special import factorial, xlogy
from itertools import product
import pytest
from sklearn.utils._testing import assert_almost_equal
from sklearn.utils._testing import assert_array_equal
from sklearn.utils._testing import assert_array_almost_equal
from sklearn.dummy import DummyRegressor
from sklearn.model_selection import GridSearchCV
from sklearn.metrics import explained_variance_score
from sklearn.metrics import mean_absolute_error
from sklearn.metrics import mean_squared_error
from sklearn.metrics import mean_squared_log_error
from sklearn.metrics import median_absolute_error
from sklearn.metrics import mean_absolute_percentage_error
from sklearn.metrics import max_error
from sklearn.metrics import mean_pinball_loss
from sklearn.metrics import r2_score
from sklearn.metrics import mean_tweedie_deviance
from sklearn.metrics import d2_tweedie_score
from sklearn.metrics import d2_pinball_score
from sklearn.metrics import d2_absolute_error_score
from sklearn.metrics import make_scorer
from sklearn.metrics._regression import _check_reg_targets
from sklearn.exceptions import UndefinedMetricWarning
def test_regression_metrics(n_samples=50):
y_true = np.arange(n_samples)
y_pred = y_true + 1
y_pred_2 = y_true - 1
assert_almost_equal(mean_squared_error(y_true, y_pred), 1.0)
assert_almost_equal(
mean_squared_log_error(y_true, y_pred),
mean_squared_error(np.log(1 + y_true), np.log(1 + y_pred)),
)
assert_almost_equal(mean_absolute_error(y_true, y_pred), 1.0)
assert_almost_equal(mean_pinball_loss(y_true, y_pred), 0.5)
assert_almost_equal(mean_pinball_loss(y_true, y_pred_2), 0.5)
assert_almost_equal(mean_pinball_loss(y_true, y_pred, alpha=0.4), 0.6)
assert_almost_equal(mean_pinball_loss(y_true, y_pred_2, alpha=0.4), 0.4)
assert_almost_equal(median_absolute_error(y_true, y_pred), 1.0)
mape = mean_absolute_percentage_error(y_true, y_pred)
assert np.isfinite(mape)
assert mape > 1e6
assert_almost_equal(max_error(y_true, y_pred), 1.0)
assert_almost_equal(r2_score(y_true, y_pred), 0.995, 2)
assert_almost_equal(r2_score(y_true, y_pred, force_finite=False), 0.995, 2)
assert_almost_equal(explained_variance_score(y_true, y_pred), 1.0)
assert_almost_equal(
explained_variance_score(y_true, y_pred, force_finite=False), 1.0
)
assert_almost_equal(
mean_tweedie_deviance(y_true, y_pred, power=0),
mean_squared_error(y_true, y_pred),
)
assert_almost_equal(
d2_tweedie_score(y_true, y_pred, power=0), r2_score(y_true, y_pred)
)
dev_median = np.abs(y_true - np.median(y_true)).sum()
assert_array_almost_equal(
d2_absolute_error_score(y_true, y_pred),
1 - np.abs(y_true - y_pred).sum() / dev_median,
)
alpha = 0.2
pinball_loss = lambda y_true, y_pred, alpha: alpha * np.maximum(
y_true - y_pred, 0
) + (1 - alpha) * np.maximum(y_pred - y_true, 0)
y_quantile = np.percentile(y_true, q=alpha * 100)
assert_almost_equal(
d2_pinball_score(y_true, y_pred, alpha=alpha),
1
- pinball_loss(y_true, y_pred, alpha).sum()
/ pinball_loss(y_true, y_quantile, alpha).sum(),
)
assert_almost_equal(
d2_absolute_error_score(y_true, y_pred),
d2_pinball_score(y_true, y_pred, alpha=0.5),
)
# Tweedie deviance needs positive y_pred, except for p=0,
# p>=2 needs positive y_true
# results evaluated by sympy
y_true = np.arange(1, 1 + n_samples)
y_pred = 2 * y_true
n = n_samples
assert_almost_equal(
mean_tweedie_deviance(y_true, y_pred, power=-1),
5 / 12 * n * (n**2 + 2 * n + 1),
)
assert_almost_equal(
mean_tweedie_deviance(y_true, y_pred, power=1), (n + 1) * (1 - np.log(2))
)
assert_almost_equal(
mean_tweedie_deviance(y_true, y_pred, power=2), 2 * np.log(2) - 1
)
assert_almost_equal(
mean_tweedie_deviance(y_true, y_pred, power=3 / 2),
((6 * np.sqrt(2) - 8) / n) * np.sqrt(y_true).sum(),
)
assert_almost_equal(
mean_tweedie_deviance(y_true, y_pred, power=3), np.sum(1 / y_true) / (4 * n)
)
dev_mean = 2 * np.mean(xlogy(y_true, 2 * y_true / (n + 1)))
assert_almost_equal(
d2_tweedie_score(y_true, y_pred, power=1),
1 - (n + 1) * (1 - np.log(2)) / dev_mean,
)
dev_mean = 2 * np.log((n + 1) / 2) - 2 / n * np.log(factorial(n))
assert_almost_equal(
d2_tweedie_score(y_true, y_pred, power=2), 1 - (2 * np.log(2) - 1) / dev_mean
)
def test_mean_squared_error_multioutput_raw_value_squared():
# non-regression test for
# https://github.com/scikit-learn/scikit-learn/pull/16323
mse1 = mean_squared_error([[1]], [[10]], multioutput="raw_values", squared=True)
mse2 = mean_squared_error([[1]], [[10]], multioutput="raw_values", squared=False)
assert np.sqrt(mse1) == pytest.approx(mse2)
def test_multioutput_regression():
y_true = np.array([[1, 0, 0, 1], [0, 1, 1, 1], [1, 1, 0, 1]])
y_pred = np.array([[0, 0, 0, 1], [1, 0, 1, 1], [0, 0, 0, 1]])
error = mean_squared_error(y_true, y_pred)
assert_almost_equal(error, (1.0 / 3 + 2.0 / 3 + 2.0 / 3) / 4.0)
error = mean_squared_error(y_true, y_pred, squared=False)
assert_almost_equal(error, 0.454, decimal=2)
error = mean_squared_log_error(y_true, y_pred)
assert_almost_equal(error, 0.200, decimal=2)
# mean_absolute_error and mean_squared_error are equal because
# it is a binary problem.
error = mean_absolute_error(y_true, y_pred)
assert_almost_equal(error, (1.0 + 2.0 / 3) / 4.0)
error = mean_pinball_loss(y_true, y_pred)
assert_almost_equal(error, (1.0 + 2.0 / 3) / 8.0)
error = np.around(mean_absolute_percentage_error(y_true, y_pred), decimals=2)
assert np.isfinite(error)
assert error > 1e6
error = median_absolute_error(y_true, y_pred)
assert_almost_equal(error, (1.0 + 1.0) / 4.0)
error = r2_score(y_true, y_pred, multioutput="variance_weighted")
assert_almost_equal(error, 1.0 - 5.0 / 2)
error = r2_score(y_true, y_pred, multioutput="uniform_average")
assert_almost_equal(error, -0.875)
score = d2_pinball_score(y_true, y_pred, alpha=0.5, multioutput="raw_values")
raw_expected_score = [
1
- np.abs(y_true[:, i] - y_pred[:, i]).sum()
/ np.abs(y_true[:, i] - np.median(y_true[:, i])).sum()
for i in range(y_true.shape[1])
]
# in the last case, the denominator vanishes and hence we get nan,
# but since the numerator vanishes as well the expected score is 1.0
raw_expected_score = np.where(np.isnan(raw_expected_score), 1, raw_expected_score)
assert_array_almost_equal(score, raw_expected_score)
score = d2_pinball_score(y_true, y_pred, alpha=0.5, multioutput="uniform_average")
assert_almost_equal(score, raw_expected_score.mean())
# constant `y_true` with force_finite=True leads to 1. or 0.
yc = [5.0, 5.0]
error = r2_score(yc, [5.0, 5.0], multioutput="variance_weighted")
assert_almost_equal(error, 1.0)
error = r2_score(yc, [5.0, 5.1], multioutput="variance_weighted")
assert_almost_equal(error, 0.0)
# Setting force_finite=False results in the nan for 4th output propagating
error = r2_score(
y_true, y_pred, multioutput="variance_weighted", force_finite=False
)
assert_almost_equal(error, np.nan)
error = r2_score(y_true, y_pred, multioutput="uniform_average", force_finite=False)
assert_almost_equal(error, np.nan)
# Dropping the 4th output to check `force_finite=False` for nominal
y_true = y_true[:, :-1]
y_pred = y_pred[:, :-1]
error = r2_score(y_true, y_pred, multioutput="variance_weighted")
error2 = r2_score(
y_true, y_pred, multioutput="variance_weighted", force_finite=False
)
assert_almost_equal(error, error2)
error = r2_score(y_true, y_pred, multioutput="uniform_average")
error2 = r2_score(y_true, y_pred, multioutput="uniform_average", force_finite=False)
assert_almost_equal(error, error2)
# constant `y_true` with force_finite=False leads to NaN or -Inf.
error = r2_score(
yc, [5.0, 5.0], multioutput="variance_weighted", force_finite=False
)
assert_almost_equal(error, np.nan)
error = r2_score(
yc, [5.0, 6.0], multioutput="variance_weighted", force_finite=False
)
assert_almost_equal(error, -np.inf)
def test_regression_metrics_at_limits():
# Single-sample case
# Note: for r2 and d2_tweedie see also test_regression_single_sample
assert_almost_equal(mean_squared_error([0.0], [0.0]), 0.0)
assert_almost_equal(mean_squared_error([0.0], [0.0], squared=False), 0.0)
assert_almost_equal(mean_squared_log_error([0.0], [0.0]), 0.0)
assert_almost_equal(mean_absolute_error([0.0], [0.0]), 0.0)
assert_almost_equal(mean_pinball_loss([0.0], [0.0]), 0.0)
assert_almost_equal(mean_absolute_percentage_error([0.0], [0.0]), 0.0)
assert_almost_equal(median_absolute_error([0.0], [0.0]), 0.0)
assert_almost_equal(max_error([0.0], [0.0]), 0.0)
assert_almost_equal(explained_variance_score([0.0], [0.0]), 1.0)
# Perfect cases
assert_almost_equal(r2_score([0.0, 1], [0.0, 1]), 1.0)
assert_almost_equal(d2_pinball_score([0.0, 1], [0.0, 1]), 1.0)
# Non-finite cases
# R² and explained variance have a fix by default for non-finite cases
for s in (r2_score, explained_variance_score):
assert_almost_equal(s([0, 0], [1, -1]), 0.0)
assert_almost_equal(s([0, 0], [1, -1], force_finite=False), -np.inf)
assert_almost_equal(s([1, 1], [1, 1]), 1.0)
assert_almost_equal(s([1, 1], [1, 1], force_finite=False), np.nan)
msg = (
"Mean Squared Logarithmic Error cannot be used when targets "
"contain negative values."
)
with pytest.raises(ValueError, match=msg):
mean_squared_log_error([-1.0], [-1.0])
msg = (
"Mean Squared Logarithmic Error cannot be used when targets "
"contain negative values."
)
with pytest.raises(ValueError, match=msg):
mean_squared_log_error([1.0, 2.0, 3.0], [1.0, -2.0, 3.0])
msg = (
"Mean Squared Logarithmic Error cannot be used when targets "
"contain negative values."
)
with pytest.raises(ValueError, match=msg):
mean_squared_log_error([1.0, -2.0, 3.0], [1.0, 2.0, 3.0])
# Tweedie deviance error
power = -1.2
assert_allclose(
mean_tweedie_deviance([0], [1.0], power=power), 2 / (2 - power), rtol=1e-3
)
msg = "can only be used on strictly positive y_pred."
with pytest.raises(ValueError, match=msg):
mean_tweedie_deviance([0.0], [0.0], power=power)
with pytest.raises(ValueError, match=msg):
d2_tweedie_score([0.0] * 2, [0.0] * 2, power=power)
assert_almost_equal(mean_tweedie_deviance([0.0], [0.0], power=0), 0.0, 2)
power = 1.0
msg = "only be used on non-negative y and strictly positive y_pred."
with pytest.raises(ValueError, match=msg):
mean_tweedie_deviance([0.0], [0.0], power=power)
with pytest.raises(ValueError, match=msg):
d2_tweedie_score([0.0] * 2, [0.0] * 2, power=power)
power = 1.5
assert_allclose(mean_tweedie_deviance([0.0], [1.0], power=power), 2 / (2 - power))
msg = "only be used on non-negative y and strictly positive y_pred."
with pytest.raises(ValueError, match=msg):
mean_tweedie_deviance([0.0], [0.0], power=power)
with pytest.raises(ValueError, match=msg):
d2_tweedie_score([0.0] * 2, [0.0] * 2, power=power)
power = 2.0
assert_allclose(mean_tweedie_deviance([1.0], [1.0], power=power), 0.00, atol=1e-8)
msg = "can only be used on strictly positive y and y_pred."
with pytest.raises(ValueError, match=msg):
mean_tweedie_deviance([0.0], [0.0], power=power)
with pytest.raises(ValueError, match=msg):
d2_tweedie_score([0.0] * 2, [0.0] * 2, power=power)
power = 3.0
assert_allclose(mean_tweedie_deviance([1.0], [1.0], power=power), 0.00, atol=1e-8)
msg = "can only be used on strictly positive y and y_pred."
with pytest.raises(ValueError, match=msg):
mean_tweedie_deviance([0.0], [0.0], power=power)
with pytest.raises(ValueError, match=msg):
d2_tweedie_score([0.0] * 2, [0.0] * 2, power=power)
power = 0.5
with pytest.raises(ValueError, match="is only defined for power<=0 and power>=1"):
mean_tweedie_deviance([0.0], [0.0], power=power)
with pytest.raises(ValueError, match="is only defined for power<=0 and power>=1"):
d2_tweedie_score([0.0] * 2, [0.0] * 2, power=power)
def test__check_reg_targets():
# All of length 3
EXAMPLES = [
("continuous", [1, 2, 3], 1),
("continuous", [[1], [2], [3]], 1),
("continuous-multioutput", [[1, 1], [2, 2], [3, 1]], 2),
("continuous-multioutput", [[5, 1], [4, 2], [3, 1]], 2),
("continuous-multioutput", [[1, 3, 4], [2, 2, 2], [3, 1, 1]], 3),
]
for (type1, y1, n_out1), (type2, y2, n_out2) in product(EXAMPLES, repeat=2):
if type1 == type2 and n_out1 == n_out2:
y_type, y_check1, y_check2, multioutput = _check_reg_targets(y1, y2, None)
assert type1 == y_type
if type1 == "continuous":
assert_array_equal(y_check1, np.reshape(y1, (-1, 1)))
assert_array_equal(y_check2, np.reshape(y2, (-1, 1)))
else:
assert_array_equal(y_check1, y1)
assert_array_equal(y_check2, y2)
else:
with pytest.raises(ValueError):
_check_reg_targets(y1, y2, None)
def test__check_reg_targets_exception():
invalid_multioutput = "this_value_is_not_valid"
expected_message = (
"Allowed 'multioutput' string values are.+You provided multioutput={!r}".format(
invalid_multioutput
)
)
with pytest.raises(ValueError, match=expected_message):
_check_reg_targets([1, 2, 3], [[1], [2], [3]], invalid_multioutput)
def test_regression_multioutput_array():
y_true = [[1, 2], [2.5, -1], [4.5, 3], [5, 7]]
y_pred = [[1, 1], [2, -1], [5, 4], [5, 6.5]]
mse = mean_squared_error(y_true, y_pred, multioutput="raw_values")
mae = mean_absolute_error(y_true, y_pred, multioutput="raw_values")
err_msg = (
"multioutput is expected to be 'raw_values' "
"or 'uniform_average' but we got 'variance_weighted' instead."
)
with pytest.raises(ValueError, match=err_msg):
mean_pinball_loss(y_true, y_pred, multioutput="variance_weighted")
with pytest.raises(ValueError, match=err_msg):
d2_pinball_score(y_true, y_pred, multioutput="variance_weighted")
pbl = mean_pinball_loss(y_true, y_pred, multioutput="raw_values")
mape = mean_absolute_percentage_error(y_true, y_pred, multioutput="raw_values")
r = r2_score(y_true, y_pred, multioutput="raw_values")
evs = explained_variance_score(y_true, y_pred, multioutput="raw_values")
d2ps = d2_pinball_score(y_true, y_pred, alpha=0.5, multioutput="raw_values")
evs2 = explained_variance_score(
y_true, y_pred, multioutput="raw_values", force_finite=False
)
assert_array_almost_equal(mse, [0.125, 0.5625], decimal=2)
assert_array_almost_equal(mae, [0.25, 0.625], decimal=2)
assert_array_almost_equal(pbl, [0.25 / 2, 0.625 / 2], decimal=2)
assert_array_almost_equal(mape, [0.0778, 0.2262], decimal=2)
assert_array_almost_equal(r, [0.95, 0.93], decimal=2)
assert_array_almost_equal(evs, [0.95, 0.93], decimal=2)
assert_array_almost_equal(d2ps, [0.833, 0.722], decimal=2)
assert_array_almost_equal(evs2, [0.95, 0.93], decimal=2)
# mean_absolute_error and mean_squared_error are equal because
# it is a binary problem.
y_true = [[0, 0]] * 4
y_pred = [[1, 1]] * 4
mse = mean_squared_error(y_true, y_pred, multioutput="raw_values")
mae = mean_absolute_error(y_true, y_pred, multioutput="raw_values")
pbl = mean_pinball_loss(y_true, y_pred, multioutput="raw_values")
r = r2_score(y_true, y_pred, multioutput="raw_values")
d2ps = d2_pinball_score(y_true, y_pred, multioutput="raw_values")
assert_array_almost_equal(mse, [1.0, 1.0], decimal=2)
assert_array_almost_equal(mae, [1.0, 1.0], decimal=2)
assert_array_almost_equal(pbl, [0.5, 0.5], decimal=2)
assert_array_almost_equal(r, [0.0, 0.0], decimal=2)
assert_array_almost_equal(d2ps, [0.0, 0.0], decimal=2)
r = r2_score([[0, -1], [0, 1]], [[2, 2], [1, 1]], multioutput="raw_values")
assert_array_almost_equal(r, [0, -3.5], decimal=2)
assert np.mean(r) == r2_score(
[[0, -1], [0, 1]], [[2, 2], [1, 1]], multioutput="uniform_average"
)
evs = explained_variance_score(
[[0, -1], [0, 1]], [[2, 2], [1, 1]], multioutput="raw_values"
)
assert_array_almost_equal(evs, [0, -1.25], decimal=2)
evs2 = explained_variance_score(
[[0, -1], [0, 1]],
[[2, 2], [1, 1]],
multioutput="raw_values",
force_finite=False,
)
assert_array_almost_equal(evs2, [-np.inf, -1.25], decimal=2)
# Checking for the condition in which both numerator and denominator is
# zero.
y_true = [[1, 3], [1, 2]]
y_pred = [[1, 4], [1, 1]]
r2 = r2_score(y_true, y_pred, multioutput="raw_values")
assert_array_almost_equal(r2, [1.0, -3.0], decimal=2)
assert np.mean(r2) == r2_score(y_true, y_pred, multioutput="uniform_average")
r22 = r2_score(y_true, y_pred, multioutput="raw_values", force_finite=False)
assert_array_almost_equal(r22, [np.nan, -3.0], decimal=2)
assert_almost_equal(
np.mean(r22),
r2_score(y_true, y_pred, multioutput="uniform_average", force_finite=False),
)
evs = explained_variance_score(y_true, y_pred, multioutput="raw_values")
assert_array_almost_equal(evs, [1.0, -3.0], decimal=2)
assert np.mean(evs) == explained_variance_score(y_true, y_pred)
d2ps = d2_pinball_score(y_true, y_pred, alpha=0.5, multioutput="raw_values")
assert_array_almost_equal(d2ps, [1.0, -1.0], decimal=2)
evs2 = explained_variance_score(
y_true, y_pred, multioutput="raw_values", force_finite=False
)
assert_array_almost_equal(evs2, [np.nan, -3.0], decimal=2)
assert_almost_equal(
np.mean(evs2), explained_variance_score(y_true, y_pred, force_finite=False)
)
# Handling msle separately as it does not accept negative inputs.
y_true = np.array([[0.5, 1], [1, 2], [7, 6]])
y_pred = np.array([[0.5, 2], [1, 2.5], [8, 8]])
msle = mean_squared_log_error(y_true, y_pred, multioutput="raw_values")
msle2 = mean_squared_error(
np.log(1 + y_true), np.log(1 + y_pred), multioutput="raw_values"
)
assert_array_almost_equal(msle, msle2, decimal=2)
def test_regression_custom_weights():
y_true = [[1, 2], [2.5, -1], [4.5, 3], [5, 7]]
y_pred = [[1, 1], [2, -1], [5, 4], [5, 6.5]]
msew = mean_squared_error(y_true, y_pred, multioutput=[0.4, 0.6])
rmsew = mean_squared_error(y_true, y_pred, multioutput=[0.4, 0.6], squared=False)
maew = mean_absolute_error(y_true, y_pred, multioutput=[0.4, 0.6])
mapew = mean_absolute_percentage_error(y_true, y_pred, multioutput=[0.4, 0.6])
rw = r2_score(y_true, y_pred, multioutput=[0.4, 0.6])
evsw = explained_variance_score(y_true, y_pred, multioutput=[0.4, 0.6])
d2psw = d2_pinball_score(y_true, y_pred, alpha=0.5, multioutput=[0.4, 0.6])
evsw2 = explained_variance_score(
y_true, y_pred, multioutput=[0.4, 0.6], force_finite=False
)
assert_almost_equal(msew, 0.39, decimal=2)
assert_almost_equal(rmsew, 0.59, decimal=2)
assert_almost_equal(maew, 0.475, decimal=3)
assert_almost_equal(mapew, 0.1668, decimal=2)
assert_almost_equal(rw, 0.94, decimal=2)
assert_almost_equal(evsw, 0.94, decimal=2)
assert_almost_equal(d2psw, 0.766, decimal=2)
assert_almost_equal(evsw2, 0.94, decimal=2)
# Handling msle separately as it does not accept negative inputs.
y_true = np.array([[0.5, 1], [1, 2], [7, 6]])
y_pred = np.array([[0.5, 2], [1, 2.5], [8, 8]])
msle = mean_squared_log_error(y_true, y_pred, multioutput=[0.3, 0.7])
msle2 = mean_squared_error(
np.log(1 + y_true), np.log(1 + y_pred), multioutput=[0.3, 0.7]
)
assert_almost_equal(msle, msle2, decimal=2)
@pytest.mark.parametrize("metric", [r2_score, d2_tweedie_score, d2_pinball_score])
def test_regression_single_sample(metric):
y_true = [0]
y_pred = [1]
warning_msg = "not well-defined with less than two samples."
# Trigger the warning
with pytest.warns(UndefinedMetricWarning, match=warning_msg):
score = metric(y_true, y_pred)
assert np.isnan(score)
def test_tweedie_deviance_continuity():
n_samples = 100
y_true = np.random.RandomState(0).rand(n_samples) + 0.1
y_pred = np.random.RandomState(1).rand(n_samples) + 0.1
assert_allclose(
mean_tweedie_deviance(y_true, y_pred, power=0 - 1e-10),
mean_tweedie_deviance(y_true, y_pred, power=0),
)
# Ws we get closer to the limit, with 1e-12 difference the absolute
# tolerance to pass the below check increases. There are likely
# numerical precision issues on the edges of different definition
# regions.
assert_allclose(
mean_tweedie_deviance(y_true, y_pred, power=1 + 1e-10),
mean_tweedie_deviance(y_true, y_pred, power=1),
atol=1e-6,
)
assert_allclose(
mean_tweedie_deviance(y_true, y_pred, power=2 - 1e-10),
mean_tweedie_deviance(y_true, y_pred, power=2),
atol=1e-6,
)
assert_allclose(
mean_tweedie_deviance(y_true, y_pred, power=2 + 1e-10),
mean_tweedie_deviance(y_true, y_pred, power=2),
atol=1e-6,
)
def test_mean_absolute_percentage_error():
random_number_generator = np.random.RandomState(42)
y_true = random_number_generator.exponential(size=100)
y_pred = 1.2 * y_true
assert mean_absolute_percentage_error(y_true, y_pred) == pytest.approx(0.2)
@pytest.mark.parametrize(
"distribution", ["normal", "lognormal", "exponential", "uniform"]
)
@pytest.mark.parametrize("target_quantile", [0.05, 0.5, 0.75])
def test_mean_pinball_loss_on_constant_predictions(distribution, target_quantile):
if not hasattr(np, "quantile"):
pytest.skip(
"This test requires a more recent version of numpy "
"with support for np.quantile."
)
# Check that the pinball loss is minimized by the empirical quantile.
n_samples = 3000
rng = np.random.RandomState(42)
data = getattr(rng, distribution)(size=n_samples)
# Compute the best possible pinball loss for any constant predictor:
best_pred = np.quantile(data, target_quantile)
best_constant_pred = np.full(n_samples, fill_value=best_pred)
best_pbl = mean_pinball_loss(data, best_constant_pred, alpha=target_quantile)
# Evaluate the loss on a grid of quantiles
candidate_predictions = np.quantile(data, np.linspace(0, 1, 100))
for pred in candidate_predictions:
# Compute the pinball loss of a constant predictor:
constant_pred = np.full(n_samples, fill_value=pred)
pbl = mean_pinball_loss(data, constant_pred, alpha=target_quantile)
# Check that the loss of this constant predictor is greater or equal
# than the loss of using the optimal quantile (up to machine
# precision):
assert pbl >= best_pbl - np.finfo(best_pbl.dtype).eps
# Check that the value of the pinball loss matches the analytical
# formula.
expected_pbl = (pred - data[data < pred]).sum() * (1 - target_quantile) + (
data[data >= pred] - pred
).sum() * target_quantile
expected_pbl /= n_samples
assert_almost_equal(expected_pbl, pbl)
# Check that we can actually recover the target_quantile by minimizing the
# pinball loss w.r.t. the constant prediction quantile.
def objective_func(x):
constant_pred = np.full(n_samples, fill_value=x)
return mean_pinball_loss(data, constant_pred, alpha=target_quantile)
result = optimize.minimize(objective_func, data.mean(), method="Nelder-Mead")
assert result.success
# The minimum is not unique with limited data, hence the large tolerance.
assert result.x == pytest.approx(best_pred, rel=1e-2)
assert result.fun == pytest.approx(best_pbl)
def test_dummy_quantile_parameter_tuning():
# Integration test to check that it is possible to use the pinball loss to
# tune the hyperparameter of a quantile regressor. This is conceptually
# similar to the previous test but using the scikit-learn estimator and
# scoring API instead.
n_samples = 1000
rng = np.random.RandomState(0)
X = rng.normal(size=(n_samples, 5)) # Ignored
y = rng.exponential(size=n_samples)
all_quantiles = [0.05, 0.1, 0.25, 0.5, 0.75, 0.9, 0.95]
for alpha in all_quantiles:
neg_mean_pinball_loss = make_scorer(
mean_pinball_loss,
alpha=alpha,
greater_is_better=False,
)
regressor = DummyRegressor(strategy="quantile", quantile=0.25)
grid_search = GridSearchCV(
regressor,
param_grid=dict(quantile=all_quantiles),
scoring=neg_mean_pinball_loss,
).fit(X, y)
assert grid_search.best_params_["quantile"] == pytest.approx(alpha)