[pymvpa] Question about classifiers

Nick Oosterhof n.n.oosterhof at googlemail.com
Sun Mar 29 16:01:26 UTC 2015

On 29 Mar 2015, at 09:50, Serin Atiani, Dr <serin.atiani at mail.mcgill.ca> wrote:

> When I use a SVM classifier, which I think  theoratically makes more sense to use with my data I get a strange cross validation confusion matrix with one row that has high numbers, and the rest is mostly zeros or ones. 
> It doesn't look right, anybody has any thoughts about this?

Indeed, that looks weird. Did you apply any normalisation to the data (de-meaning or z-scoring)? Especially SVM classifiers may behave not so well when data is not normalised. 
Also, apart from nearest neighbour (which usually does not perform well with fMRI data), have you tried another classifier such as LDA?

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