"How can I control the feature demonsion using Kernel PCA?"

zhangce
zhangce New Altair Community Member
edited November 5 in Community Q&A

I'm using kernel pca in rapidminer, however I found no place to tune the demonsion of transformed space like PCA... i.e., after carried out Kernel PCA, I always get a space with # of demonsion equals to the # of sample datas...how can I tune it just PCA? thanks.

    <operator name="KernelPCA" class="KernelPCA">
        <parameter key="kernel_type" value="polynomial"/>
    </operator>
    <operator name="ModelApplier (2)" class="ModelApplier">
    </operator>

Answers

  • land
    land New Altair Community Member
    Hi,
    unfortunatly you have to perform a conventional feature selection after the kernelPCA, since it always returns the number of features it was possible to calculate. Unlike the PCA this new features are NOT ordered by their variance, prohibiting the usual heuristic of removing the least variant directions in data space.

    Greetings,
      Sebastian
  • zhangce
    zhangce New Altair Community Member

    Thank you very much~ :)~