function?[]?=?checkNumericalGradient（）
%?This?code?can?be?used?to?check?your?numerical?gradient?implementation?
%?in?computeNumericalGradient.m
%?It?analytically?evaluates?the?gradient?of?a?very?simple?function?called
%?simpleQuadraticFunction?（see?below）?and?compares?the?result?with?your?numerical
%?solution.?Your?numerical?gradient?implementation?is?incorrect?if
%?your?numerical?solution?deviates?too?much?from?the?analytical?solution.
??
%?Evaluate?the?function?and?gradient?at?x?=?[4;?10];?（Here?x?is?a?2d?vector.）
x?=?[4;?10];
[value?grad]?=?simpleQuadraticFunction（x）;

%?Use?your?code?to?numerically?compute?the?gradient?of?simpleQuadraticFunction?at?x.
%?（The?notation?“@simpleQuadraticFunction“?denotes?a?pointer?to?a?function.）
numgrad?=?computeNumericalGradient（@simpleQuadraticFunction?x）;

%?Visually?examine?the?two?gradient?computations.??The?two?columns
%?you?get?should?be?very?similar.?
disp（[numgrad?grad]）;
fprintf（‘The?above?two?columns?you?get?should?be?very?similar.\n（Left-Your?Numerical?Gradient?Right-Analytical?Gradient）\n\n‘）;

%?Evaluate?the?norm?of?the?difference?between?two?solutions.??
%?If?you?have?a?correct?implementation?and?assuming?you?used?EPSILON?=?0.0001?
%?in?computeNumericalGradient.m?then?diff?below?should?be?2.1452e-12?
diff?=?norm（numgrad-grad）/norm（numgrad+grad）;
disp（diff）;?
fprintf（‘Norm?of?the?difference?between?numerical?and?analytical?gradient?（should?be?end


??
function?[valuegrad]?=?simpleQuadraticFunction（x）
%?this?function?accepts?a?2D?vector?as?input.?
%?Its?outputs?are:
%???value:?h（x1?x2）?=?x1^2?+?3*x1*x2
%???grad:?A?2x1?vector?that?gives?the?partial?derivatives?of?h?with?respect?to?x1?and?x2?
%?Note?that?when?we?pass?@simpleQuadraticFunction（x）?to?computeNumericalGradients?we‘re?assuming
%?that?computeNumericalGradients?will?use?only?the?first?returned?value?of?this?function.

value?=?x（1）^2?+?3*x（1）*x（2）;

grad?=?zeros（2?1）;
grad（1）??=?2*x（1）?+?3*x（2）;
grad（2）??=?3*x（1）;

end

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

?????文件???????1982??2011-01-05?17:27??starter\checkNumericalGradient.m

?????文件???????1259??2015-05-20?19:00??starter\computeNumericalGradient.m

?????文件???????2647??2011-01-05?01:48??starter\display_network.m

?????文件???20971720??2011-01-03?21:39??starter\IMAGES.mat

?????文件????????622??2011-01-05?00:13??starter\initializeParameters.m

?????文件???????3251??2011-01-03?21:39??starter\minFunc\ArmijoBacktrack.m

?????文件????????807??2011-01-03?21:39??starter\minFunc\autoGrad.m

?????文件????????901??2011-01-03?21:39??starter\minFunc\autoHess.m

?????文件????????317??2011-01-03?21:39??starter\minFunc\autoHv.m

?????文件????????870??2011-01-03?21:39??starter\minFunc\autoTensor.m

?????文件????????385??2011-01-03?21:39??starter\minFunc\callOutput.m

?????文件???????1845??2011-01-03?21:39??starter\minFunc\conjGrad.m

?????文件????????995??2011-01-03?21:39??starter\minFunc\dampedUpdate.m

?????文件???????2421??2011-01-03?21:39??starter\minFunc\example_minFunc.m

?????文件???????1604??2011-01-03?21:39??starter\minFunc\example_minFunc_LR.m

?????文件????????107??2011-01-03?21:39??starter\minFunc\isLegal.m

?????文件????????924??2011-01-03?21:39??starter\minFunc\lbfgs.m

?????文件???????2408??2011-01-03?21:39??starter\minFunc\lbfgsC.c

?????文件???????7707??2011-01-03?21:39??starter\minFunc\lbfgsC.mexa64

?????文件???????7733??2011-01-03?21:39??starter\minFunc\lbfgsC.mexglx

?????文件???????9500??2011-01-03?21:39??starter\minFunc\lbfgsC.mexmac

?????文件??????12660??2011-01-03?21:39??starter\minFunc\lbfgsC.mexmaci

?????文件???????8800??2011-01-03?21:39??starter\minFunc\lbfgsC.mexmaci64

?????文件???????7168??2011-01-03?21:39??starter\minFunc\lbfgsC.mexw32

?????文件???????9728??2011-01-03?21:39??starter\minFunc\lbfgsC.mexw64

?????文件????????614??2011-01-03?21:39??starter\minFunc\lbfgsUpdate.m

?????文件????????417??2011-01-03?21:39??starter\minFunc\logistic\LogisticDiagPrecond.m

?????文件????????216??2011-01-03?21:39??starter\minFunc\logistic\LogisticHv.m

?????文件????????659??2011-01-03?21:39??starter\minFunc\logistic\LogisticLoss.m

?????文件???????1154??2011-01-03?21:39??starter\minFunc\logistic\mexutil.c

............此處省略31個文件信息