From: LEWYN LI (ll2150_at_columbia.edu)
Date: Tue Apr 25 2006 - 12:39:23 CDT
Dear Richard,
         Are you familiar with the LINUX environment and script languages 
such as awk?  If yes, here is my "quick-and-dirty" solution.  Using LINUX, 
you can first extract all the energy lines:
grep ENERGY output.log > output2.dat
         You can then use awk to extract the columns you want (x = step, 
y = total energy):
awk {'print $x " " $y'} output2.dat > output3.dat
         You can then quickly plot output3.dat i.e. plot energy as a 
function of step.  Visually identify the minimum, and find the 
corresponding frame in your trajectory.  Or you can write a short program 
in C or any other language convenient for you to extract the minimal 
energy.
         Hope this helps!
                                                         LEWYN
On Tue, 25 Apr 2006, Richard Wood wrote:
> Hi all,
>
> I've currently involved myself in a rather time consuming project.  I'm 
> running 1 ns of dynamics and I'd like to be able to find the minimum 
> energy frame from these 10000 steps that are saved in my trajectory 
> (1000000 steps in the output file), and write out the value of this 
> minimum energy and save the correspondin coordinates to a .pdb (or 
> .coor) 
> file.  What I am currently doing is opening the output file in MS Word, 
> cutting it into pieces, opening the pieces in MS Excel, finding the 
> minimum energy for each piece, recording these, the finding the overall 
> minimum, and going back and locating the step number that corresponds to 
> this minimum energy.  Then I save the coordinates that frame from my 
> trajectory using NAMD.   These coordinates then go into the next MD 
> calculation.
>
> This whole process takes about 2 hours or so, almost the entire time it 
> takes for my MD calculation to run.  Surely there must be a better way 
> to do this, using NAMD or a NAMD-like script.
>
> I'd appreciate any suggestions on how I can do this more effeciently, 
> as I have 42 such calculations to analyze and run.  As it stands now, 
> with other things I have to do, it takes about a day to do one of these. 
> So I'm looking at this bein a 6 week process, unles I can somehow speed 
> the analysis part up.
>
> TIA,
> Richard
>
>
>
>
> Richard L. Wood, Ph. D.
> Computational Chemist
> Cockeysville, MD 21030
> rwoodphd_at_yahoo.com
>
>
>
>
>
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