Cost function [Machine Learning]

gistfile1.matlab

function J = computeCost(X, y, theta)
%COMPUTECOST Compute cost for linear regression
%   J = COMPUTECOST(X, y, theta) computes the cost of using theta as the
%   parameter for linear regression to fit the data points in X and y

% Initialize some useful values
m = length(y); % number of training examples
value = 0;
t = theta.';

for n = 1:m
    value = value + ( (t(1) * X(n,1) + t(2) * X(n,2) ) - y(n,1) )^2;
end
% You need to return the following variables correctly 
J = 1/(2 * m) * value;

% =========================================================================

end