VMD-L Mailing List

From: Peter Freddolino (petefred_at_ks.uiuc.edu)
Date: Tue Jul 10 2007 - 15:22:13 CDT

Hi Julie,
as far as I know, "User" is a vmd-only concept, and is used for storing
pretty much any timestep-dependent data people might want. People
wanting to color by velocity will normally need to have a script to fill
in the User column of each frame with the appropriate velocities; this
can be done fairly easily, for example, by writing a velocity dcd in
other MD programs. I'm not familiar with DLPOLY, though, so I don't know
how one accesses velocity data in it (I'm guessing it's a similar
mechanism, where you can write a velocity file alongside your coordinate
trajectory).
Best,
Peter

Stern, Julie wrote:
> Hello,
> I'm interested in displaying velocity information from a dlpoly history file. I did find on this
> group that I have to color by User. But I don't know a couple of things to make that work. Does
> anyone know if the velocity info in a dlpoly history file is in a User column? I thought its just its
> normal place for velocity data. How do I then access that info? Do I call it velocity by name
> in a tcl script? How do I point that info to the User label? I just needed a few more details, since
> I haven't done that before.
>
> Thanks.
>
> --Julie
>