How to use rbf_kernel parameters with svmtrain() and svmclassify() for svm classification

By using linear kernel I got the result using svmtrain() and svmclassify() function. But the result obtained is not so accurate. When I used rbf_kernel I got an error as follows. Please help me how to use parameters with example

>> load fisheriris >> data = [meas(:,1), meas(:,2)]; >> groups = ismember(species,'setosa'); >> [train, test] = crossvalind('holdOut',groups); >> cp = classperf(groups); >> svmStruct = svmtrain(data(train,:),groups(train),'showplot',true);

//Error below

>> svmStruct = svmtrain(data(train,:),groups(train),'kernel_function','1'); ??? Error using ==> svmtrain at 266 Unknown Kernel Function 1.

Answer 1

[Tom Lane]

From your description, it sounds like you intended

svmStruct = svmtrain(data(train,:),groups(train),'kernel_function','rbf');

In any case, the error message simply means that '1' isn't a valid value to follow the 'kernel_function' parameter name.

[Yasir Mohammed]

svmStruct =svmtrain(data(train,:),groups(train),'kernel_function','rbf'); i used this but i also have the same error

Error using svmclassify (line 75) Unknown parameter name: kernel_function.

Error in SVMtest (line 14) testresult = svmclassify(svmStructSurprise,testone,'kernel_function','rbf' );

>>

Answer 2

[Pratik Oak]

Use this:

svmStruct = svmtrain(data(train,:),groups(train),'RBF_Sigma','1')

name of kernel function should be added

Answer 3

[Farman Shah]

_ _ _ _ _ _ _ _ _ _ _ * * * * * * * * * *svmStruct =svmtrain(data(train,:),groups(train),'kernel_function','rbf'); i used this but i also have the same error

Error using svmclassify (line 75) Unknown parameter name: kernel_function.

Error in SVMtest (line 14) testresult = svmclassify(svmStructSurprise,testone,'kernel_function','rbf' );

>>**********____

Dear you are getting the error because you are adding 'Kernel_Function', 'polynomial', 'Polyorder', 4 to svmclassify.Add this kernal parameter to the trainsvm function instead..i.e

    SVMStruct = svmtrain(features_train,labels_train,'Kernel_Function', 'polynomial', 'Polyorder', 4);

and it will work... _____

[Tsalsabilla Winny Junika]

what about the svmclassify? Is that any change for that code???