From: Axel Kohlmeyer (
Date: Mon Mar 22 2004 - 12:56:30 CST

>>> "AM" == Adam Marcus <> writes:

AM> Hello Everyone,

AM> I am relatively new to VMD and I am already a big fan of its powerful and
AM> vast tools. Currently, I am writing a tcl script to align the frames of an
AM> animation using rmsd. As an intermediate step, I need to take a frame of
AM> an animation and make a copy of it so that I can proceed with my work on
AM> that copy without affecting what happens to the original frame that it is
AM> derived from. Is there a way to copy a selection of all of the atoms of a
AM> frame, or just the frame itself to a new location? For reference, this is
AM> the way I select the frame (using tcl):

AM> set sel [atomselect $mol $seltext frame $j]

AM> Please let me know if I am being to vague or if you need more
AM> information. Thank you very much for your time and assistance in
AM> advance! Have a great day!

hi adam,

i suggest you just create several selections (e.g. sela, selb)
using the same $seltext and then just move each selection to
the desired frame (e.g. 1 and 2) by

$sela frame 1
$sela update

$selb frame 2
$selb update

with the frame subcommand you will advance the coordinates of
the selection to the coordinates of frame X and the update subcommand
re-evaluates the selection text for the currently active frame of
a selection. i found this to be a very convenient way to work
though a trajectory without having to create (and delete!) selections
all the time.

happy hacking,
      axel kohlmeyer

AM> -Adam Marcus

Axel Kohlmeyer       e-mail:
Lehrstuhl fuer Theoretische Chemie          Phone: ++49 (0)234/32-26673
Ruhr-Universitaet Bochum - NC 03/53         Fax:   ++49 (0)234/32-14045
D-44780 Bochum
If you make something idiot-proof, the universe creates a better idiot.