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Re: [lammps-users] Define average density during simulation
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Re: [lammps-users] Define average density during simulation

From: alberto <voodoo.bender@...24...>
Date: Fri, 23 Jun 2017 16:03:34 +0200


I tried to define
variable    dal equal atoms/vol (in real units)


fix   avload all ave/time 1 1 1 v_dal file ave.log

to obtain the comulative average loading

in my case 100 points

the file ave.log report a wrong average

1 0.1
2 0.3
3 0.0


I expect that

Step.   Atoms.  Vol.  Density.   Av
1.        1.     10    0.1.     0.1
2.        3.     10    0.3.     0.2
3         0.     10     0       0.1

Av = ( 0.1+ 0.3) /2 = 0.2

I must define manually _expression_ to calculate it. I can print the results in themo_style ?


2017-06-22 16:17 GMT+02:00 alberto <voodoo.bender@...24...>:

I define a variable
variable    dal equal atoms/vol
and I use fix ave/time as

fix   avload all ave/time 1 100000 1 v_dal ave one,  where 100000 is the total steps of my simulation
but I obtain message error

ERROR: Illegal fix ave/time command


2017-06-21 16:20 GMT+02:00 Steve Plimpton <sjplimp@...24...>:
The fix ave/time command can do averaging with a moving window or cummulative
ave, see its doc page and keywords.


On Tue, Jun 20, 2017 at 2:15 PM, alberto <voodoo.bender@...36.....24...> wrote:
during a gcmc simulation, I produce density of gas per step. I would produce other column with the average density for every n-th step: for second step the average between the first and second, the third as the average between the first, the second, the third, and so on.
I'm a young user of lammps, and on manual I found the keyword fix ave/time command. It's a good idea to produce the results that I wish, or exist other procedure, or it's not possible during lammps run?



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