[gmx-users] Retaining only .xtc files and deleting .trr files

[Kai Zhuang]

> > To be more specific, beside the usage you have specified which other
> > programs uses only trr file but not xtc file.
> 
> None. As said, you loose the velocities and in addition you loose (some)
> precision on the coordinates. Coordinates in xtc are stored in
> nanometers with three decimal places. This is sufficient for all kinds
> analysis that I am aware of.

thoeretically, you can regenerate the velocities from position + time.
 and we know
both precisely so we should be able to recover trr from xtc.
that's not saying i know how, haven't had to do that yet.
Kai 

On 5/20/05, Anton Feenstra <feenstra at few.vu.nl> wrote:
> sunita at chem.iitb.ac.in wrote:
> 
> > Dear Kai,
> >
> > Thank you for your response.
> >
> > To restart the simulation I can use the last trr file as it contains
> > velocity term in addition to coordinates. For this purpose I plan to keep
> > the last trr file. Once I accumulate data for example 50 ns trajectory and
> > make xtc file of whole 50 ns, can I delete the trr files?
> 
> I normaly store them on tape or dvd, then delete them. In addition, I
> only write a frame to the trr file every 20-50 ps or so (in stead of 1
> or 2 frames per ps for xtc).
> 
> > To be more specific, beside the usage you have specified which other
> > programs uses only trr file but not xtc file.
> 
> None. As said, you loose the velocities and in addition you loose (some)
> precision on the coordinates. Coordinates in xtc are stored in
> nanometers with three decimal places. This is sufficient for all kinds
> analysis that I am aware of.
> 
> 
> --
> Groetjes,
> 
> Anton
> 
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> |  _   _  ___,| K. Anton Feenstra                                     |
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-- 
Kai Zhuang
BioMedical Engineering @ University of Toronto
kai dot zhuang at gmail dot com
kai.zhuang at gmail.com
6478314789