완료

ex2/costFunction.m

@@ -20,8 +20,10 @@ grad = zeros(size(theta));
 % Note: grad should have the same dimensions as theta
 %
 
+hx = sigmoid(X*theta);
+J = sum(-y.*log(hx) - (1.-y).*log(1.-hx))/m;
 
-
+grad = sum((hx-y).*X)/m;