[ata]

Hi foamers
I have some problem with residual plotting in OF. I don't know how can I plot residuals that I have saved in log file? Can any one help me?
Thanks

Ata

[ata]

Hi
Thanks I got it.

Ata

[kumar]

Hello ,
to plot the residuals you have to first run the foamLog script on your log file, if you are using OF-1.5

just run
FoamLog logfile

it will produce a directory of name logs/. This will contain all the files you need for plotting. Use simple gnuplot script to plot the values.

If you are running a unsteady calculation then you can plot the final residuals files against the times to verify if your equation is converged at all time steps.
bye
hope this helps
K.Suresh kumar

[elvis]

you can use pyfoam for a couple of nice features like plotting residuals
http://openfoamwiki.net/index.php/Co...mPlotRunner.py

grettings

elvis

[ata]

Hi every one
When I try to plot residuals with gnuplot I got this error:
plot "< cat log | grep 'Solving for Ux' | cut -d' ' -f9 | tr -d ','" title 'Ux' with lines,"< cat log | grep 'Solving for Uy' | cut -d' ' -f9 | tr -d ','" title 'Uy' with lines,"< cat log | grep 'Solving for Uz' | cut -d' ' -f9 | tr -d ','" title 'Uz' with lines,"< cat log | grep 'Solving for omega' | cut -d' ' -f9 | tr -d ','" title 'omega' with lines,"< cat log | grep 'Solving for k' | cut -d' ' -f9 | tr -d ','" title 'k' with lines,"< cat log | grep 'Solving for p' | cut -d' ' -f9 | tr -d ','" title 'p' with lines
^
"Residuals", line 10: warning: Skipping data file with no valid points

plot "< cat log | grep 'Solving for Ux' | cut -d' ' -f9 | tr -d ','" title 'Ux' with lines,"< cat log | grep 'Solving for Uy' | cut -d' ' -f9 | tr -d ','" title 'Uy' with lines,"< cat log | grep 'Solving for Uz' | cut -d' ' -f9 | tr -d ','" title 'Uz' with lines,"< cat log | grep 'Solving for omega' | cut -d' ' -f9 | tr -d ','" title 'omega' with lines,"< cat log | grep 'Solving for k' | cut -d' ' -f9 | tr -d ','" title 'k' with lines,"< cat log | grep 'Solving for p' | cut -d' ' -f9 | tr -d ','" title 'p' with lines
^
"Residuals", line 10: warning: Skipping data file with no valid points

plot "< cat log | grep 'Solving for Ux' | cut -d' ' -f9 | tr -d ','" title 'Ux' with lines,"< cat log | grep 'Solving for Uy' | cut -d' ' -f9 | tr -d ','" title 'Uy' with lines,"< cat log | grep 'Solving for Uz' | cut -d' ' -f9 | tr -d ','" title 'Uz' with lines,"< cat log | grep 'Solving for omega' | cut -d' ' -f9 | tr -d ','" title 'omega' with lines,"< cat log | grep 'Solving for k' | cut -d' ' -f9 | tr -d ','" title 'k' with lines,"< cat log | grep 'Solving for p' | cut -d' ' -f9 | tr -d ','" title 'p' with lines
^
"Residuals", line 10: warning: Skipping data file with no valid points

plot "< cat log | grep 'Solving for Ux' | cut -d' ' -f9 | tr -d ','" title 'Ux' with lines,"< cat log | grep 'Solving for Uy' | cut -d' ' -f9 | tr -d ','" title 'Uy' with lines,"< cat log | grep 'Solving for Uz' | cut -d' ' -f9 | tr -d ','" title 'Uz' with lines,"< cat log | grep 'Solving for omega' | cut -d' ' -f9 | tr -d ','" title 'omega' with lines,"< cat log | grep 'Solving for k' | cut -d' ' -f9 | tr -d ','" title 'k' with lines,"< cat log | grep 'Solving for p' | cut -d' ' -f9 | tr -d ','" title 'p' with lines
Can any body help me?
Regards

Ata

[ata]

Hi Elvis
Thank you
Can you send me some tutorial.
Thanks

Ata

[Marta]

Hi ata,
I found this piece of advice last month when i needed to find out how to plot the residuals of a simulation. It is taken from another section of this forum, I followed this steps and I managed to plot the residuals, so I think it can help you too.

Tutorial on "How to plot the residuals (and forces) graphically on screen on-the-fly"

Step 1:
Start the calculation and make it write out a log-file. for example

turbFoam >log

"log" is the name of the log-file to be output. It is written into the main-case-folder.

Step 2:
If desired you can open a new console-window of the main-case-folder and follow the text-output by the command

tail -f log

"log" is the name of the log-file to be read in. To stop reading the file constantly just use Crtl+C

Step 3:
To plot the residuals graphically on the screen you can use gnuplot that is delivered with linux already.
Within the main-case-folder you have to put a text file with a name e.g. "Residuals" (also see attachments).
The file should contain the following gnuplot properties:

set logscale y
set title "Residuals"
set ylabel 'Residual'
set xlabel 'Iteration'
plot "< cat log | grep 'Solving for Ux' | cut -d' ' -f9 | tr -d ','" title 'Ux' with lines,\
"< cat log | grep 'Solving for Uy' | cut -d' ' -f9 | tr -d ','" title 'Uy' with lines,\
"< cat log | grep 'Solving for Uz' | cut -d' ' -f9 | tr -d ','" title 'Uz' with lines,\
"< cat log | grep 'Solving for omega' | cut -d' ' -f9 | tr -d ','" title 'omega' with lines,\
"< cat log | grep 'Solving for k' | cut -d' ' -f9 | tr -d ','" title 'k' with lines,\
"< cat log | grep 'Solving for p' | cut -d' ' -f9 | tr -d ','" title 'p' with lines
pause 1
reread

The pause-command sets the seconds till reload. Deletion makes it faster in some cases.

Execute the command

gnuplot Residuals -

in the main-case-folder.

This way I did not have any errors by gnu plot, maybe it could help you too.

Marta

[ata]

Hi Marta
Thank you very much but I already have seen this tutorial and when I try it I got that error.
Best regards

Ata

[lth]

Hi Foamers,

Using output& folder to monitor jobs and FinalResidual was giving similar errors.
------------------------------------
"FinalResiduals", line 8: warning: Skipping data file with no valid points openfoam
"Final Residuals", line 8: x range is invalid
-----------------------------------

By quick switch of names in the FinalResidual code
to "< cat output | ... from "< cat log | ... has it working fine.

Best, Lori

[Bertrand]

Hello Marta,

Thanks a lot for posting this kind of tutorial : makes OF life much easier! ;-)
As I am not really familiar with gnuplot syntax, I was wondering what exactly we need to change in Residuals.txt in order to plot the Courant Number mean and max?

Best regards,

Bertrand

[Bertrand]

OK,

Sorry for the silly question, I'm new to Linux as well, but I just found how to deal with the syntax...

[megacrout]

Originally Posted by ata

Hi Marta
Thank you very much but I already have seen this tutorial and when I try it I got that error.
Ata

Hey ata.

This happens if the Residuals-file contains more terms to look for than there are in the log file (e.g. k or epsilon). Either delete the "reread" command at the end of the Residuals-file (ugly solution) or delete the lines that make gnu look for parameters that it is never going to find.

Tibo

[joel.lehikoinen]

Originally Posted by ata

Hi every one
When I try to plot residuals with gnuplot I got this error:
plot "< cat log | grep 'Solving for Ux' | cut -d' ' -f9 | tr -d ','" title 'Ux' with lines,"< cat log | grep 'Solving for Uy' | cut -d' ' -f9 | tr -d ','" title 'Uy' with lines,"< cat log | grep 'Solving for Uz' | cut -d' ' -f9 | tr -d ','" title 'Uz' with lines,"< cat log | grep 'Solving for omega' | cut -d' ' -f9 | tr -d ','" title 'omega' with lines,"< cat log | grep 'Solving for k' | cut -d' ' -f9 | tr -d ','" title 'k' with lines,"< cat log | grep 'Solving for p' | cut -d' ' -f9 | tr -d ','" title 'p' with lines
^
"Residuals", line 10: warning: Skipping data file with no valid points
...

Can any body help me?
Regards

Ata

This script doesn't work out of the box for all solvers, you have to modify it, depending on your turbulence model and the algorithm (especially number of loops) you are using. You may need to twiddle with the field specified for the cut command. The best way to check if it works is to just run this command in a terminal:

cat log | grep 'Solving for Ux' | cut -d' ' -f9

This should output a floating point number followed by a comma. If it doesn't, then you need to see which field it is actually reading (see man pages for cut).

Also, if you are running some other model than k-omega the script will be unable to plot omega (naturally). And if you are running a solver with buoancy, then you need to grep p_rgh instead of p. This script is very handy, it just requires some Unix-fu to get it working.