Hello,

I had another question on 3dUndump. In the past I've always used the "-master" option with this command rather than the "-dimen" (and then you could use "-mask" and perhaps "-rss" option).

I was curious what some advantages are to using -dimen/-mask over -master, and also wanted to clarify how AFNI handles the -rss option.

The masks I've been working with have previously been resampled to the resolution I want to use, so in that case I suppose -master is no different from specifying 'dimen' and 'mask'. Perhaps if you used dimen and mask you could use a mask resampled to an arbitrary resolution?

For the -rss (spheres option), I was curious if a radius larger than the voxel resolution would ever be used. (And if so, how AFNI would handle overlapping sphere's from nearby voxels). I guess using a sphere smaller than the voxel resolution confuses me as you would have leftover space in the voxel with no data, if that makes sense.

Basically, I just want to make sure I'm not missing anything useful here about these alternative options for 3dUndump. Sorry if I've missed any of this info elsewhere.

Thanks,

John S.