open source pkg v1

pkg/OpenFace/model_training/CCNF/CCRF/lib/CalcSigmaCCRFflat.m

@@ -0,0 +1,26 @@
+function [ SigmaInv] = CalcSigmaCCRFflat(alphas, betas, n, PrecalcB_flat)
+%CALCSIGMAPRF Summary of this function goes here
+%   Detailed explanation goes here
+% constructing the Sigma (that is laid out in an efficient way for
+% symmertic matrices
+ 
+    A = sum(alphas) * eye(n);
+
+    % calculating the B from the paper
+    % using the precalculated lower triangular elements of B without beta
+    Btmp = PrecalcB_flat * betas;        
+    
+    % not faster
+
+    % now make it into a square symmetric matrix
+    B = zeros(n,n);
+    on = tril(true(n,n));
+    B(on) = Btmp;
+    B = B';
+    B(on) = Btmp;
+    
+    % Combine A and B
+    SigmaInv = 2 * (A + B);
+
+end
+