Bug #2873
Simple way to get last frame from trajectory
Description
At https://mailman-1.sys.kth.se/pipermail/gromacs.org_gmx-users/2019-February/124407.html, a user asked for a simple way to get the last frame from a trajectory.
Currently gmx trjconv -f -dump 9999999 doesn't work because an arbitrary time is observed to be inconsistent with the time series.
We could implement gmx dump -f traj.tng -lastframe conf.gro
History
#1 Updated by Erik Lindahl 6 months ago
- Tracker changed from Feature to Bug
- Affected version set to 2019
Since the documentation for the dump option is "Dump frame nearest specified time (ps)", this sounds like it's a bug that it does not do that :-)
Instead of adding another option, IMHO we should just make the present one behave according to the specifications.
#2 Updated by Berk Hess 6 months ago
The specifications are imprecise. I think I implemented this and I think it gives the nearest frame within a the time step between frames.
We can extend it to work exactly to the current specification, but it seems to me that this is not a very intuitive way to get the last frame.
#3 Updated by Mark Abraham 6 months ago
- Description updated (diff)
#4 Updated by Mark Abraham 6 months ago
For 2019, I suggest we amend the documentation to reflect the behaviour, since making changes to trjconv is undesirable.
For 2020, I suggest we implement something like my earlier suggestion of gmx dump -f -lastframe