cost function in classification learner app

How is it possible to use a costfunction/ penalty function for a Support Vector Machine in the classification Learner App?

If it is not possible, is there a way to train a SVM manually for more than 2 classes?

Answer 1

[Stephan]

Hi,

a cost function is not available as far as i know. For more than two classes you could use the function

fitcecoc

see documentation here:

https://de.mathworks.com/help/stats/fitcecoc.html?searchHighlight=fitcecoc&s_tid=doc_srchtitle

Best regards

Stephan

[Artem Bykanov]

Thanks for your answer!

Now I have another problem: In the classificationLearner App I can export a trained Model. (It is a 1x1 struct)

How can generate the same trained model? Because if I try to classify with fitcecoc and validate with crossval I dont get this 1x1 struct.

Best regards

[Stephan]

Hi,

when you choose the option "generate code" from the button export model in the classification learner app you get a good commented script with matlab-code doing exactly what you choosed in classification learner app. Then you can modify for your purposes as you want. If you do SVM model with more than 2 classes, i guess the function classification learner will use

fitcecoc

See here for further information:

https://de.mathworks.com/help/stats/export-classification-model-for-use-with-new-data.html

Best regards

Stephan