Re: [AMBER] math operations in cpptraj

From: Daniel Roe <>
Date: Mon, 9 Dec 2013 09:43:09 -0700


At the moment you can't apply math operations to data sets in cpptraj
(although this functionality is tentatively planned for the next release).
You can however, simply calculate all phi/psi torsions with the
'multidihedral' command, e.g.:

multidihedral M0 phi psi out phipsi.dat

This will put all phi/psi torsions into columns in phipsi.dat; you could
then pretty easily write a script to do what you want.

Hope this helps,


On Mon, Dec 9, 2013 at 9:26 AM, Andre C. Stiel <
> wrote:

> hi, is there a simple way to do math automatically on a dataset in ptraj.
> Like, for example, generating phi-psi-angles for all residues over all
> frames and then for every residue
> subtract the first frame angles, to have only the difference and look
> for major changes?
> Thanks
> _______________________________________________
> AMBER mailing list

Daniel R. Roe, PhD
Department of Medicinal Chemistry
University of Utah
30 South 2000 East, Room 201
Salt Lake City, UT 84112-5820
(801) 587-9652
(801) 585-6208 (Fax)
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Received on Mon Dec 09 2013 - 09:00:03 PST
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