Hi, Jin-
To the integer-only funniness about "I range": thanks for mentioning this. We actually happened to notice this just a couple weeks ago. This should be fixed if you update your AFNI version, and float values won't get round. (The fix looks to have gone in at AFNI_25.2.09, so just sliiiightly after your current version, but you might as well update to the most recent, anyways.)
Again, thanks, and let us know how that goes.
--pt