Regularized Gradient

ex8/cofiCostFunc.m

@@ -44,8 +44,13 @@ J = 0.5 * sum(sum(R.*(X*Theta'-Y).^2)) ...
     + 0.5 * lambda * sum(sum(Theta.^2)) ...
     + 0.5 * lambda * sum(sum(X.^2));
 
-X_grad = (R.*(X*Theta'-Y))*Theta;  % mov X user * uxer X feat = mov X feat
-Theta_grad = (R.*(X*Theta'-Y))'*X;  % user X mov * mov X feat = user X feat
+% mov X user * uxer X feat = mov X feat
+X_grad = (R.*(X*Theta'-Y))*Theta ...
+         + lambda*X;
+
+% user X mov * mov X feat = user X feat
+Theta_grad = (R.*(X*Theta'-Y))'*X ...
+             + lambda*Theta;
 
 % =============================================================