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

% 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.

## for i = 1:m,
##   J = J + ((X(i, :) * theta) - y(i)) ^ 2;
## end;

J = sum(((X * theta) - y) .^ 2);

J = 1 / (2 * m) * J;


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

end
