VMD-L Mailing List

From: Dr. Seth Olsen (seth.olsen_at_gmail.com)
Date: Thu Sep 21 2006 - 21:25:09 CDT

Hi Axel,

If this is the case, then something is definitely wrong. Attached please
find a python script named 'VMDAngstrom.py', a pdb file named '
AngstromScale.pdb', and a JPG file named 'Angstrom.jpg'. The pdb contains 2
nitrogen atoms placed at (-0.5,0.0,0.0) and (0.5,0.0,0.0). The script loads
this pdb (lines drawstyle), then creates a graphics molecule and draws a
thick black cylinder cylinder with endpoints at (-0.5,0.0,0.0) and (0.5,0.0,
0.0). The JPG shows just what I got when I ran the script.

I am running a precompiled linux binary of VMD 1.8.5. I have pointed
PYTHONHOME to a precompiled python binary (compiled for 1.8.4, but there is
no current distribution as far as I can tell). My OS is FC5 running on a
P4.

What's even more frustrating is that it seems that different results are
obtained if you create the graphics molecule, then load the pdb.
Regardless, I don't think this is the way VMD was intended to work.

Cheers,

Seth

On 9/22/06, Axel Kohlmeyer <akohlmey_at_cmm.chem.upenn.edu> wrote:
>
> On 9/21/06, Dr. Seth Olsen <seth.olsen_at_gmail.com> wrote:
> >
> > Hi VMDers,
> >
> > I've been writing python scripts to visualize 3N dimensional vectors (
> i.e.
> > molecular modes) as arrows attached to atoms. I've been having a lot of
> > problems with length distortions and after checking my code over several
> > times I think that the problem might be that I have assumed that VMD
> uses an
> > internal length scale that I am not. What are the units that VMD uses?
>
> all graphics objects are drawn on an angstrom scale.
>
> axel.
> >
> > Cheers,
> >
> > Seth
> >
> > --
> > ccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccms
> >
> > Dr Seth Olsen, PhD
> > Postdoctoral Fellow, Biomolecular Modeling Group
> > Centre for Computational Molecular Science
> > Australian Institute for Bioengineering and Nanotechnology (Bldg. 75)
> > The University of Queensland
> > Qld 4072, Brisbane, Australia
> >
> > tel (617) 3346 3976
> > fax (617) 33654623
> > email: s.olsen1_at_uq.edu.au
> > Web: www.ccms.uq.edu.au
> >
> > ccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccms
> > The opinions expressed here are my own and do not reflect the positions
> of
> > the University of Queensland.
>
>
> --
> =======================================================================
> Axel Kohlmeyer akohlmey_at_cmm.chem.upenn.edu http://www.cmm.upenn.edu
> Center for Molecular Modeling -- University of Pennsylvania
> Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
> tel: 1-215-898-1582, fax: 1-215-573-6233, office-tel: 1-215-898-5425
> =======================================================================
> If you make something idiot-proof, the universe creates a better idiot.
> 

-- 
ccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccms
Dr Seth Olsen, PhD
Postdoctoral Fellow, Biomolecular Modeling Group
Centre for Computational Molecular Science
Australian Institute for Bioengineering and Nanotechnology (Bldg. 75)
The University of Queensland
Qld 4072, Brisbane, Australia
tel (617) 3346 3976
fax (617) 33654623
email: s.olsen1_at_uq.edu.au
Web: www.ccms.uq.edu.au
ccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccmsccms
The opinions expressed here are my own and do not reflect the positions of
the University of Queensland.

Angstrom.jpg