I've run a searchligh with a linear SVM on my data and am trying to save it in
Nifti format. I've done the following:

clf = LinearNuSVMC()
cv = CrossValidatedTransferError(TransferError(clf),NFoldSplitter(cvtype=1))
s1 = Searchlight(cv, radius=5)
s1_map = s1(dataset)

orig_s1_map = dataset.mapReverse(N.array(s1_map))
NiftiImage(orig_s1_map).save('searchlight_results.nii.gz')

This did successfully save, however, when I opened the file in Afni the
overlayed file was about 1/6 the size of my high res scan. Clearly, not the same
space as my original dataset. How can I map the results into the same space as
my original dataset? 

Thanks,
Amy