[gmx-users] weird nst*out problem

David van der Spoel spoel at xray.bmc.uu.se
Thu Jan 9 13:40:44 CET 2003

On Thu, 2003-01-09 at 10:59, Bert de Groot wrote:
> David wrote:
>   3000000.25000
>   3000000.50000
>   3000000.50000
>   3000000.75000
>   3000001.00000
>   3000001.25000
>   3000001.50000
>   3000001.50000
> (note that if you write out less frequently, like most users would do,
> the problem starts much later)
> If we want to prevent this, would it suffice to use a double for the
> time variable in mdrun in our local gromacs version, or would it be better 
> to completely switch to double precision?
That seems to be a bit overkill. For trr files you can use a double
precision version to renumber the times in the trr file (trjconv -t0
etc.). You can also use separate files (which you probably have already
when you have trajectory files that long) and set the starting time to
zero for each of them, and keep track of the real time otherwise.

In your local version you can write the time in double in the xtc file,
but for compatibility I wouldn't like that in the standard format. 

Groeten, David.
Dr. David van der Spoel, 	Biomedical center, Dept. of Biochemistry
Husargatan 3, Box 576,  	75123 Uppsala, Sweden
phone:	46 18 471 4205		fax: 46 18 511 755
spoel at xray.bmc.uu.se	spoel at gromacs.org   http://xray.bmc.uu.se/~spoel

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