ksubramz/nibabel-1 — comment on commit fa0db82497e5817294ba0d6e36f4099aa3846eb4
File: nibabel/freesurfer/mghformat.py line 247
By ksubramz:

Hi Matthew,

I don't think empty values are allowed here. The MGH format needs to carry a valid numbers. The default are Mdc = [[-1, 0, 0], [0, 0, -1], [0, 1, 0]] and Pxyz_c = [0, 0, 0]

http://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/MghFormat

I'll add a test that checks the writer that if an affine transform is not given, it writes these values by default.