Fs retinotopy

As discussed in yesterday's lab meeting, here is a  function to create volume files 

I am I have two issues requiring some feedback: 

1. Currently, I am generating intermediate mgh files as temp-files and not keeping those. Should we keep them around? I am not sure whether that wouldn't be a good idea. 

2. Does this work? I have tried this with a few subjects, but I am not sure whether this generalizes to all kinds of data. Beta-testers needed.