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
-----------?---------??----------?-----??----
?????目錄???????????0??2016-03-30?17:10??softmax_exercise\
?????文件????????1510??2016-03-30?10:32??softmax_exercise\computeNumericalGradient.m
?????文件?????????811??2014-03-25?21:18??softmax_exercise\loadMNISTImages.m
?????文件?????????516??2011-04-25?17:32??softmax_exercise\loadMNISTLabels.m
?????目錄???????????0??2016-03-25?20:07??softmax_exercise\minFunc\
?????文件????????3251??2011-01-03?21:39??softmax_exercise\minFunc\ArmijoBacktrack.m
?????文件?????????807??2011-01-03?21:39??softmax_exercise\minFunc\autoGrad.m
?????文件?????????901??2011-01-03?21:39??softmax_exercise\minFunc\autoHess.m
?????文件?????????317??2011-01-03?21:39??softmax_exercise\minFunc\autoHv.m
?????文件?????????870??2011-01-03?21:39??softmax_exercise\minFunc\autoTensor.m
?????文件?????????385??2011-01-03?21:39??softmax_exercise\minFunc\callOutput.m
?????文件????????1845??2011-01-03?21:39??softmax_exercise\minFunc\conjGrad.m
?????文件?????????995??2011-01-03?21:39??softmax_exercise\minFunc\dampedUpdate.m
?????文件????????2421??2011-01-03?21:39??softmax_exercise\minFunc\example_minFunc.m
?????文件????????1604??2011-01-03?21:39??softmax_exercise\minFunc\example_minFunc_LR.m
?????文件?????????107??2011-01-03?21:39??softmax_exercise\minFunc\isLegal.m
?????文件?????????924??2011-01-03?21:39??softmax_exercise\minFunc\lbfgs.m
?????文件????????2408??2011-01-03?21:39??softmax_exercise\minFunc\lbfgsC.c
?????文件????????7707??2011-01-03?21:39??softmax_exercise\minFunc\lbfgsC.mexa64
?????文件????????7733??2011-01-03?21:39??softmax_exercise\minFunc\lbfgsC.mexglx
?????文件????????9500??2011-01-03?21:39??softmax_exercise\minFunc\lbfgsC.mexmac
?????文件???????12660??2011-01-03?21:39??softmax_exercise\minFunc\lbfgsC.mexmaci
?????文件????????8800??2011-01-03?21:39??softmax_exercise\minFunc\lbfgsC.mexmaci64
?????文件????????7168??2011-01-03?21:39??softmax_exercise\minFunc\lbfgsC.mexw32
?????文件????????9728??2011-01-03?21:39??softmax_exercise\minFunc\lbfgsC.mexw64
?????文件?????????614??2011-01-03?21:39??softmax_exercise\minFunc\lbfgsUpdate.m
?????目錄???????????0??2016-03-25?20:07??softmax_exercise\minFunc\logistic\
?????文件?????????417??2011-01-03?21:39??softmax_exercise\minFunc\logistic\LogisticDiagPrecond.m
?????文件?????????216??2011-01-03?21:39??softmax_exercise\minFunc\logistic\LogisticHv.m
?????文件?????????659??2011-01-03?21:39??softmax_exercise\minFunc\logistic\LogisticLoss.m
?????文件????????1154??2011-01-03?21:39??softmax_exercise\minFunc\logistic\mexutil.c
............此處省略29個文件信息