I'm sorry, I don't yet understand much of the MRI (and file extension) terminology.
The GRADS.dat file is 3 columns by 288 rows.
The HCP data comes from scans with 95,96,97 gradients (=288).
So, I think I'm getting this now, my last question being: for the 1dDW_Grad_o_Mat, do I truncate my bvals to
bvals[1..287]
bvals[1..288]
bvals[0..286]
bvals[0..287]
I'm assuming bvals[1..288], to remove the first gradient (B=0) and capture the remaining 287?
Thanks again for your time! Hopefully I can proceed on my own from here on in!