ex3 cost function

hcfw007 · Apr 27, 2019 · f418c31 · f418c31
1 parent ebec689
commit f418c31
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/machine-learning-ex3/ex3/lrCostFunction.m b/machine-learning-ex3/ex3/lrCostFunction.m
@@ -38,10 +38,12 @@
 
 
 
+h = sigmoid(X * theta); 
+J = (1 / m) * sum(- y .* log(h) - (1 - y) .* log(1 - h)) + lambda / (2 * m) * (theta(2: end)' * theta(2: end));
+grad = (1 / m) * X' * (h - y);
 
-
-
-
+grad(1) =  X(:, 1)' * (h - y) / m; 
+grad(2: end) = (X(:, 2: end)' * (h - y)  + lambda * theta(2: end)) / m;