changeset 6:141d81a2acf5 default tip

Remove usage of sum function in cost function (thanks Jeroen Willems)
author Jordi Gutiérrez Hermoso <jordigh@octave.org>
date Tue, 08 Nov 2011 03:30:56 -0500
parents a4c4da8f4ac0
children
files costFunction.m costFunctionReg.m
diffstat 2 files changed, 2 insertions(+), 2 deletions(-) [+]
line wrap: on
line diff
--- 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
--- 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 ;