function?numgrad?=?computeNumericalGradient（J?theta）
%?numgrad?=?computeNumericalGradient（J?theta）
%?theta:?a?vector?of?parameters
%?J:?a?function?that?outputs?a?real-number.?Calling?y?=?J（theta）?will?return?the
%?function?value?at?theta.?
??
%?Initialize?numgrad?with?zeros
numgrad?=?zeros（size（theta））;

%%?----------?YOUR?CODE?HERE?--------------------------------------
%?Instructions:?
%?Implement?numerical?gradient?checking?and?return?the?result?in?numgrad.??
%?（See?Section?2.3?of?the?lecture?notes.）
%?You?should?write?code?so?that?numgrad（i）?is?（the?numerical?approximation?to）?the?
%?partial?derivative?of?J?with?respect?to?the?i-th?input?argument?evaluated?at?theta.??
%?I.e.?numgrad（i）?should?be?the?（approximately）?the?partial?derivative?of?J?with?
%?respect?to?theta（i）.
%????????????????
%?Hint:?You?will?probably?want?to?compute?the?elements?of?numgrad?one?at?a?time.?

%?epsilon=0.0001;
%?n=size（theta1）;
%?E=eye（n）;
%?for?i=1:n
%?????delta=E（:i）*epsilon;
%?????numgrad（i）=（J（theta+delta）-J（theta-delta））/（epsilon*2.0）;
%?end

epsilon?=?10^（-4）;
n?=?size（theta?1）;
J1?=?zeros（1?1）;
J2?=?zeros（1?1）;
grad?=?zeros（size（numgrad））;
temp1?=?zeros（size（theta））;
temp2?=?zeros（size（theta））;

for?i?=?1?:?n
????temp1?=?theta;
????temp2?=?theta;
????temp1（i）?=?temp1（i）?+?epsilon;
????temp2（i）?=?temp2（i）?-?epsilon;
????[J1?grad]?=?J（temp1）;
????[J2?grad]?=?J（temp2）;
????numgrad（i）?=?（J1?-?J2）?/?（2*epsilon）;
end




%%?---------------------------------------------------------------
end

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????1510??2016-03-30?10:32??softmax分類（Matlab程序）\computeNumericalGradient.m

?????文件????????811??2014-03-25?21:18??softmax分類（Matlab程序）\loadMNISTImages.m

?????文件????????516??2011-04-25?17:32??softmax分類（Matlab程序）\loadMNISTLabels.m

?????文件???????3251??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\ArmijoBacktrack.m

?????文件????????807??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\autoGrad.m

?????文件????????901??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\autoHess.m

?????文件????????317??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\autoHv.m

?????文件????????870??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\autoTensor.m

?????文件????????385??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\callOutput.m

?????文件???????1845??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\conjGrad.m

?????文件????????995??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\dampedUpdate.m

?????文件???????2421??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\example_minFunc.m

?????文件???????1604??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\example_minFunc_LR.m

?????文件????????107??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\isLegal.m

?????文件????????924??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\lbfgs.m

?????文件???????2408??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\lbfgsC.c

?????文件???????7707??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\lbfgsC.mexa64

?????文件???????7733??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\lbfgsC.mexglx

?????文件???????9500??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\lbfgsC.mexmac

?????文件??????12660??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\lbfgsC.mexmaci

?????文件???????8800??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\lbfgsC.mexmaci64

?????文件???????7168??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\lbfgsC.mexw32

?????文件???????9728??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\lbfgsC.mexw64

?????文件????????614??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\lbfgsUpdate.m

?????文件????????417??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\logistic\LogisticDiagPrecond.m

?????文件????????216??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\logistic\LogisticHv.m

?????文件????????659??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\logistic\LogisticLoss.m

?????文件???????1154??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\logistic\mexutil.c

?????文件????????317??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\logistic\mexutil.h

?????文件????????227??2011-01-03?21:39??softmax分類（Matlab程序）\minFunc\logistic\mylogsumexp.m

............此處省略33個文件信息