Octave-CostFunction

假设 X= [1 1;1 2;1 3]

y = [1;2;3]

theta = [0;0]

costFunction J :

 function J = costFunction(X,y,theta)
   m = size(X,1);
   predictions = X*theta;
   Errors = (predictions - y).^2;
   J = 1/(2*m)*sum(Errors);
 endfunction

J = costFunction(X,y,theta)　　　　:得到结果为     杲湩س୔J =  2.3333