Coursera吴恩达机器学习课程第二周编程作业含附加题

Coursera吴恩达机器学习课程第二周编程作业（含附加题）

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+（theta‘*X（i:）‘-y（i））^2;
%end;
%J=J/（2*m）;

%h=X*theta-y;
%J=1/（2*m）*sum（h.^2）;
J=1/（2*m）*（X*theta-y）‘*（X*theta-y）;


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

end

 属性            大小     日期    时间   名称
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     目录           0  2017-12-08 16:03  machine-learning-ex1\
     目录           0  2017-12-09 00:21  machine-learning-ex1\ex1\
     文件      162304  2017-12-08 15:48  machine-learning-ex1\ex1.doc
     文件      489928  2017-03-14 09:40  machine-learning-ex1\ex1.pdf
     文件         766  2017-12-09 00:20  machine-learning-ex1\ex1\computeCost.m
     文件         707  2017-12-09 00:47  machine-learning-ex1\ex1\computeCostMulti.m
     文件        3916  2017-12-08 20:32  machine-learning-ex1\ex1\ex1.m
     文件        1359  2017-03-14 09:40  machine-learning-ex1\ex1\ex1data1.txt
     文件         657  2017-03-14 09:40  machine-learning-ex1\ex1\ex1data2.txt
     文件        4460  2017-03-14 09:40  machine-learning-ex1\ex1\ex1_multi.m
     文件        1342  2017-12-09 00:48  machine-learning-ex1\ex1\featureNormalize.m
     文件        1196  2017-12-09 00:01  machine-learning-ex1\ex1\gradientDescent.m
     文件         982  2017-12-09 00:48  machine-learning-ex1\ex1\gradientDescentMulti.m
     文件         102  2017-12-08 08:25  machine-learning-ex1\ex1\hello.txt
     目录           0  2017-12-08 02:11  machine-learning-ex1\ex1\lib\
     目录           0  2017-12-08 02:11  machine-learning-ex1\ex1\lib\jsonlab\
     文件        1624  2017-03-14 09:40  machine-learning-ex1\ex1\lib\jsonlab\AUTHORS.txt
     文件        3862  2017-03-14 09:40  machine-learning-ex1\ex1\lib\jsonlab\ChangeLog.txt
     文件         881  2017-03-14 09:40  machine-learning-ex1\ex1\lib\jsonlab\jsonopt.m
     文件        1551  2017-03-14 09:40  machine-learning-ex1\ex1\lib\jsonlab\LICENSE_BSD.txt
     文件       18732  2017-03-14 09:40  machine-learning-ex1\ex1\lib\jsonlab\loadjson.m
     文件       15574  2017-03-14 09:40  machine-learning-ex1\ex1\lib\jsonlab\loadubjson.m
     文件         771  2017-03-14 09:40  machine-learning-ex1\ex1\lib\jsonlab\mergestruct.m
     文件       19369  2017-03-14 09:40  machine-learning-ex1\ex1\lib\jsonlab\README.txt
     文件       17462  2017-03-14 09:40  machine-learning-ex1\ex1\lib\jsonlab\savejson.m
     文件       16123  2017-03-14 09:40  machine-learning-ex1\ex1\lib\jsonlab\saveubjson.m
     文件        1094  2017-03-14 09:40  machine-learning-ex1\ex1\lib\jsonlab\varargin2struct.m
     文件        1195  2017-03-14 09:40  machine-learning-ex1\ex1\lib\makeValidFieldName.m
     文件        5562  2017-03-14 09:40  machine-learning-ex1\ex1\lib\submitWithConfiguration.m
     文件          30  2017-12-08 08:21  machine-learning-ex1\ex1\new.txt
     文件         665  2017-12-09 00:49  machine-learning-ex1\ex1\normalEqn.m
............此处省略4个文件信息