added math_util

dbm_lib/dbm_features/raw_features/util/math_util.py

@@ -0,0 +1,57 @@
+"""
+file_name: facial_tremor
+project_name: cdx_analysis
+created: 2019-03-16
+author: Deshana Desai
+"""
+import sys, os, glob, cv2
+import pandas as pd
+import numpy as np
+
+
+def euclidean_distance(point1, point2):
+    """
+    Compute euclidean distance between points
+    """
+
+    return np.sqrt((point1[0] - point2[0])**2 + (point1[1] - point2[1])**2)
+
+
+# def detect_peaks()
+
+
+def expand_landmarks(landmarks):
+    """
+    util method to expand landmark list:
+    eg: [1,2] -> [['l1_x', 'l1_y'], ['l2_x', 'l2_y']]
+    """
+    return [['l{}_x'.format(l), 'l{}_y'.format(l)] for l in landmarks]
+
+
+
+def calc_displacement_vec(df, landmarks, num_frames):
+    """
+    Calculates displacement vector frame by frame
+    """
+
+    landmarks = expand_landmarks(landmarks)
+
+    disp_vec = np.zeros((len(landmarks), num_frames))
+    prev_point = np.zeros((len(landmarks), 2))
+
+    # initialize
+    for j, pair in enumerate(landmarks):
+        first_row = df.iloc[0]
+        prev_point[j] = (first_row[pair[0]], first_row[pair[1]])
+
+
+    for i in range(num_frames):
+        frame_row = df.iloc[i]
+        for j, pair in enumerate(landmarks):
+            x, y = pair[0], pair[1]
+            current = (frame_row[x], frame_row[y])
+            deviation = euclidean_distance( current, prev_point[j])
+            disp_vec[j][i] = deviation
+            prev_point[j] = current
+
+    return disp_vec