`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.
ma450921
commented
5 years ago
`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.
% Loop implementation %for i = 1:m, % J = J + (((X(i,:) * theta) - y(i)) ^ 2); %end;
% Vectorized implementation J = sum(((X theta) - y) .^ 2); %why it is (X theta) and not (theta * X)
J = 1 / (2 m) J; //
% =========================================================================
end`