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
.
h=X
*theta
-y
;
h2 = h
.^2
;
J = sum
(h2
)/(2
*m
);
% =========================================================================
end
代价函数的公式： 因为我对函数和矩阵运算不是很熟悉，只能分布实现代价函数。实现后，感觉还不是很难。
