[pymvpa] Creating a nifti using a vector of intensities and a reference image

[Yaroslav Halchenko]

On Tue, 03 Jul 2018, Usman Sheikh wrote:

>    Hi PyMVPA experts,
>    I have a vector of voxel intensities that I want to be wrapped into a
>    NIfTI image. I also have a reference dataset for reverse mapping. But when
>    I use map2nifti function to create the NIfTI image, I get an image that I
>    expect but with a gray background for zero voxel intensity instead of the
>    expected black background. For reference, I am attaching an image with
>    this email. The dataset image has previously been preprocessed using
>    ZScoreMapper and PolyDetrendMapper.

gray/black -- colors are relative ;)  at least plot a colorbar to see
what are the actual values.  you might be having negative values so
overall range then such that 0 is somewhere in the middle of the range
(min/max) and thus gray.

-- 
Yaroslav O. Halchenko
Center for Open Neuroscience     http://centerforopenneuroscience.org
Dartmouth College, 419 Moore Hall, Hinman Box 6207, Hanover, NH 03755
Phone: +1 (603) 646-9834                       Fax: +1 (603) 646-1419
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