Folks (maybe Bob?):
Trying to understand what syntax 1deval will digest -- couple of questions:

1. How do I reconcile the command line param -a fred.1D with the syntax 'fred.1D[5,9,17]'? Does this mean I can write:
-a fred.1D[5,9,17]
... and if so what does this mean? Ie: I don't understand how variable a can have 3 values. (So I'm guessing it means something else that might be useful...)

2. How do I specify that one of the variables should grab values from "next row" or "previous row", like I can use index offsets in 3dcalc?

FWIW, the actual problem we'd like to solve is calculating derivative from 1D file (eg: 3dvolreg output), without having to make copies of the 1D file with first or last rows deleted.

Thanks, Graham