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Hi, Mark<br>
<br>
Thank you for your reply.<br>
I know -skip -sep is more robust.<br>
Since the definition talked about nr-th frame but not nr-th ps.<br>
<br>
-skip int 1 Only write every nr-th frame<br>
-[no]sep bool no Write each frame to a separate .gro,
.g96 or .pdb file<br>
<br>
The problem is that -skip 1000 -sep didn't consist of several time
frames in the same file but just write nr-th frame.<br>
That's why I use -split 1000 -timestep 1 according these definitions
found in manual.<br>
<br>
-split time 0 Start writing new file when t MOD split =
first time (ps)<br>
-timestep time 0 Change time step between input frames
(ps)<br>
With <tt>-dt</tt> it is possible to reduce the number of frames in
the output. This option relies on the accuracy of the times
in your input trajectory, so if these are inaccurate use the
<tt>-timestep</tt> option to modify the time (this can be done
simultaneously).<br>
<br>
Would you please teach how to use -skip -sep to get the same kind of
file which include all of 1000ps time frames together in a 1ns gro
file?<br>
<br>
I'll appreciate to any helps.<br>
<br>
Sincerely yours,<br>
Hsin-Lin<br>
<blockquote type="cite">
<pre>><i> Hi,
</i>><i>
</i>><i> My time unit is 1ps and today I have 300ns data generated by parallel simulation.
</i>><i> I use trjconv -split 1000 on my trajectory but get the truncated end at t= 5000.00000
</i>><i> Theoretically it should stop at t= 1000.000
</i>><i> I found that I don't have t= 1000.00000 frame but have t= 1000.00006, 2000.00012, 3000.00024, and t= 4000.00024.
</i>><i>
</i>><i> I know I can add -timestep 1 to solve this problem and let file can be truncated at t= 1000.00006.
</i>><i>
</i>><i> How does this kind of inaccurate time frames happen?
</i>><i> Is this trajectory a wrong result?
</i>><i>
</i>I just wrote a FAQ+wiki page for this, since it gets asked a bit. See <a href="http://www.gromacs.org/Documentation/Floating_Point_Arithmetic">http://www.gromacs.org/Documentation/Floating_Point_Arithmetic</a>
trjconv -skip -sep is a more robust approach here
Mark
</pre>
</blockquote>
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