Hi Amit, I also encountered the same problem you mentioned. In v4.5, when using -nstlp wiht large value (e.g., 10000000), I got one file "localpressure.dat0". I tested first several frames of a trajectory, the calculated pressure is not the average of the pressure of individual frames.
Btw, did you use CHARMM FF in your simulations and how did you convert the tpr files from v 4.5 to v 4.0? Cheers Jianguo ________________________________ From: Amit Choubey <kgp.a...@gmail.com> To: Jianguo Li <ljg...@yahoo.com.sg>; Discussion list for GROMACS users <gmx-users@gromacs.org> Sent: Friday, 1 July 2011 10:32:07 Subject: Re: [gmx-users] Re: local pressure v4.5 issues Hello Everyone, The git version of local pressure calculation at http://repo.or.cz/w/gromacs.git/shortlog/refs/heads/release-4-5-localpressure is broken. I could not get it to work for my simulations. I installed gromacs local pressure version 4.0 from ftp://ftp.gromacs.org/pub/tmp/ I used gromacs-4.0.2_localpressure.tar.gz in that folder. The pressure values printed using this version seem reasonable to me. I converted all the tpr files from v 4.5 to v 4.0. The output of the mdrun in v 4.0 is a single file "localpressure.dat" . On the contrary in v 4.5 there were separate "localpressure.dat*" files for each frame. I am not sure what exactly is the content of "localpressure.dat". Does it have the time averaged value of pressure tensor for each voxel ? It doesnt seem so to me because i tried it over only two frames (3 reruns were done for two frames separately and a .trr which had these two frames only) and the numbers did not seem to be averages. Can someone help me in figuring out what is going on ? Amit On Tue, Jun 21, 2011 at 9:16 AM, Amit Choubey <kgp.a...@gmail.com> wrote: > > >On Tue, Jun 21, 2011 at 1:13 AM, Jianguo Li <ljg...@yahoo.com.sg> wrote: > >Hi Amit, >> >>May I ask you a question? >>In your calculation of local pressure using a trajectory file, did you get a >>single averaged localpressure.dat file? Or else you get a bunch of separate >>files for each frame (e.g., localpressure.dat0, localpressure.dat1, >>localpressure.dat2 ....)? >> >Yes I do get different files for different trajectories. All the files seem to >have the same problem ie a very large/small number printed as tensor elements >of >the pressure for some of the voxels. > > >Do you have such problems ? Could we compare our methodologies to use the >local >pressure version ? > >Amit > >>Thank you very much! >> >>Cheers, >>Jianguo >> >> >> >> >> ________________________________ From: Amit Choubey <kgp.a...@gmail.com> >>To: Discussion list for GROMACS users <gmx-users@gromacs.org> >>Sent: Monday, 20 June 2011 07:08:03 >>Subject: [gmx-users] Re: local pressure v4.5 issues >> >> >>Dear all, >> >> >>I did another simulation with only SPC water. Then I used the local pressure >>gromacs to calculate the stresses. It seems to be reasonable. >> >> >>I am not sure how to figure out what goes wrong with my previous simulations >>when plugged into the local pressure gromacs. >> >> >>Could someone help me in figuring out whats the issue ? >> >> >>Thank You. >> >> >>On Fri, Jun 17, 2011 at 6:00 PM, Amit Choubey <kgp.a...@gmail.com> wrote: >> >>Dear all, >>> >>>I installed the git version of local pressure calculation from >>> >>>http://repo.or.cz/w/gromacs.git/shortlog/refs/heads/release-4-5-localpressure >>> >>>The I invoked mdrun >>> >>>mdrun_lp -v -s rerun.tpr -g rerun_log -olp -rerun traj0.gro -localpgrid 0.1 >>> >>>This created a file named "localpressure.dat0". This is a binary file so I >>>could >>>not look at it directly. I am not sure if there is a tool in the gromacs to >>>look >>>at it directly. >>> >>> >>>To look at the data in "localpressure.dat0" I used the planar_av.c code >>>available in "pressure-tools" folder at >>> >>>http://md.chem.rug.nl/cgmartini/index.php/3d >>> >>>When I look at the Pressure tensor averaged over xy plane, some of the >>>numbers >>>are reasonable but few of them are ridiculously large numbers which is not >>>expected. >>> >>> >>>I checked this on two different simulations and I got the same problems. The >>>simulations had run OK previously. >>> >>>Could someone help me in figuring our whats going on ? >>> >>>Amit Choubey >>> >>> >> >
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