computeCostMulti.m

function J = computeCostMulti(X, y, theta)
%COMPUTECOSTMULTI Compute cost for linear regression with multiple variables
%   J = COMPUTECOSTMULTI(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

% You need to return the following variables correctly 
J = 0;

% ====================== YOUR CODE HERE ======================
% Instructions: Compute the cost of a particular choice of theta
%               You should set J to the cost.
%J = (1/2*m)*sum((X*theta-y)'*(X*theta-y));
%printf("Compute Cost\n");
%disp(J);
predictions = X * theta;
sqrErrors = (predictions - y).^2;
J = (1/(2*m)) * sum(sqrErrors);
printf("The size of J is\n");
disp(size(J));
printf("Compute Cost\n");
disp(J);
% =========================================================================

end