From: Michael Doig (m.doig_at_sms.ed.ac.uk)
Date: Mon Oct 29 2012 - 05:20:27 CDT

  I am trying to visualise a LAMMPS dump file, by colouring the atoms
via a velocity component, vx say.

I have found this script in the mailing list history (29th Sept 2011)
from Axel Kohlmeyer.

However, I am having trouble modifying it. The smallest limit for
setting the colour scale in VMD seems to be +/- 0.01, whereas my
velocity data is in a much smaller range [-0.00005 --> 0.00005]. I am
trying to multiply all the user values (or the velocities as they are
read in) by a common factor (say 10000), to allow me to colour them.

I realise this should be very simple, but I cannot get the syntax
correct. Can someone tell me what I need to add to the script below
to do this.

Thanks in advance,
Michael.

---------------------------------------------------------
set framecount [molinfo top get numframes]
set sel [atomselect top all]
for {set frame_no 0} {$frame_no<$framecount} {incr frame_no} {
         $sel frame $frame_no
         $sel set {user user2 user3} [$sel get {vx vy vz}]
}
$sel delete

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