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GMX Developers,<br>
<span class="Apple-tab-span" style="white-space: pre; "></span>I have a long simulation, and I noticed that at some point the timestamp in the xtc file gets rounded. For sufficiently long simulations, this leads to many frames having the same timestamp. Here
is a sample output from g_dist<br>
<br>
15689440.0000000 4.1125884 -0.8720000 -3.9099998 0.9300003<br>
15689441.0000000 4.0926588 -0.8410001 -3.8730006 1.0209999<br>
15689441.0000000 4.0091296 -0.8900001 -3.7840004 0.9809999<br>
15689442.0000000 3.9852955 -0.8520000 -3.7909999 0.8860002<br>
15689443.0000000 3.9080644 -0.8450000 -3.6969995 0.9440002<br>
15689443.0000000 3.8975551 -0.8559999 -3.6749997 0.9760003<br>
15689444.0000000 3.9498629 -0.8680000 -3.7300005 0.9670000<br>
15689444.0000000 3.9664337 -0.9370000 -3.7350001 0.9510002<br>
<br>
<br>
I then use g_energy for the edr file from the same run:<br>
<br>
15689440.200000 -68.322456<br>
15689440.800000 -24.153179<br>
15689441.400000 -172.497147<br>
15689442.000000 -143.456650<br>
15689442.600000 -225.489212<br>
15689443.200000 -185.056137<br>
15689443.800000 -192.895752<br>
<br>
<br>
I checked gmx_dist.c, and it appears to not be performing any rounding, so it looks like the timestamp is rounded before it is saved to the xtc. Though, perhaps I am misunderstanding the code.<br>
<br>
Additionally, when I run gmxcheck on the xtc file, I get many errors, similar to:<br>
<br>
Reading frame 0 time 15689440.000 <br>
Reading frame 2 time 15689441.000 <br>
Timesteps at t=1.56894e+07 don't match (1, 0)<br>
Reading frame 3 time 15689442.000 <br>
Timesteps at t=1.56894e+07 don't match (0, 1)<br>
Reading frame 5 time 15689443.000 <br>
Timesteps at t=1.56894e+07 don't match (1, 0)<br>
Reading frame 6 time 15689444.000 <br>
<br>
<br>
In later runs, this gets worse, and it appears to round to the nearest 2 ps, and not 1 ps.<br>
<br>
These errors seem consistent with my impression that the timestamp is rounded before it is saved to the xtc.<br>
<br>
Is there a need for this rounding? I'm having trouble finding the source of it, so I'm also not sure how to disable it. If you can point me to the right lines, that would be great.<br>
<br>
Your help is much appreciated.<br>
<br>
Paul Whitford<br>
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