# HG changeset patch
# User Jordi Gutiérrez Hermoso <jordigh@octave.org>
# Date 1320741056 18000
# Node ID 141d81a2acf5f0c548eaa8e09eaf84cc62b739b2
# Parent  a4c4da8f4ac089a1af5e19834f0bdc2548c69171
Remove usage of sum function in cost function (thanks Jeroen Willems)

diff --git a/costFunction.m b/costFunction.m
--- a/costFunction.m
+++ b/costFunction.m
@@ -9,7 +9,7 @@
   ## h_theta(x)
   ht = sigmoid (X*theta); 
 
-  J = -sum (y.*log (ht) + (1 - y).*log (1 - ht))/m
+  J = - (y'*log (ht) + (1 - y)'*log (1 - ht))/m;
   grad = X'*(ht - y)/m;
 
 endfunction
diff --git a/costFunctionReg.m b/costFunctionReg.m
--- a/costFunctionReg.m
+++ b/costFunctionReg.m
@@ -11,7 +11,7 @@
   ## h_theta(x)
   ht = sigmoid (X*theta); 
 
-  J = -sum (y.*log (ht) + (1 - y).*log (1 - ht))/m \
+  J = -(y'*log (ht) + (1 - y)'*log (1 - ht))/m \
       + lambda*sum (theta(2:end).^2)/(2*m);
 
   grad = (X'*(ht - y) + [0; lambda*theta(2:end)])/m ;