From: Axel Kohlmeyer (
Date: Wed Nov 17 2010 - 10:39:07 CST

On Wed, 2010-11-17 at 23:59 +0800, 程昌利 wrote:

this looks like a cut-&-paste error,
i.e. the space that you copied is not
inserted as a "proper" ASCII space.

try retyping the code by hand, especially the for loop
header to see if it goes away.


> Hello all When I run an analysis script example in VMD ug , the screen
> display :missing operator at _@_in expression "$i _@_$n". The
> script is as follows(page 172,version 1.8.7) : #find waters near the
> protein for each frame and writes a pdb file
> proc waters_near_protein {} {
> set sel [atomselect top "water and same residue as (within 2 of
> protein)"]
> set n [molinfo top get numframes]
> for {set i 0} {$i $n} {incr i} {
> $sel frame $i
> $sel update
> $sel writepdb water_$i.pdb }
> } I want to konw it is a bug or not, and how can I solve the
> problem.
> Best regards

Dr. Axel Kohlmeyer
Institute for Computational Molecular Science
Temple University, Philadelphia PA, USA.