From: Peter Freddolino (
Date: Sat Aug 05 2006 - 15:17:21 CDT

>> Basically how do I write the following (which is awk-like) in the Tk
>> console?
>> if ($<col number> == <some value>) >> atom_selection_1
> VMD does not work like this.
Just to elaborate on this last point, you can't really concatenate
selections in this way. You can do two things:
set sel [atomselect top "beta <some value>"] (or user, or any of the
columns that the atom selector does recognize. Also, beta < 0.5 or some
such also works)

or, if you want to effectively combine two selections, you can do a set

set sel3 [atomselect top "[$sel1 text] or [$sel2 text]"]