[KateEisenhower]

Dear all,

Currently I am trying to set up an OpenFOAM environment on Amazon EC2. As with many other computing servers, I am accessing it via cli only. So how do you monitor your simulation (e.g. Residuals) on line?

I hope I could make the problem clear, if not feel free to ask.

Best regards, and thanks in advance,

Kate

[Tobi]

Hi Kate,

I am not sure but can you access via ssh in a terminal? Then it should be possible to plot the residuals on your computer with common tools like gnuplot, the new foam function (residuals) or pyFoamPlotWatcher.py. I did this on my own cluster a while ago.

[anttiad9000]

Hello Kate,

If I understood correctly you do not have access to graphical utilies so you cannot use the GUI for gnuplot. Here is another way you can do it.

The most important thing is that you are logging the simulation to a file with >, e.g. :

icoFoam > log.icoFoam

Then a very straight forward and kind of manual way to do this without using pyFoam is to use 'grep' and combination of grep and cut to get the essential numbers and save them again to a new file, e.g. (this is for foam-extend):

grep "p, Initial residual" log.icoFoam | cut -d ' ' -f 9 | sed 's/,//g' > p_residuals

sed is used to remove the comma after the value, -f 9 means the 9th field from left which will be printed, you can also replace cut with: awk '{print $8}'. It uses a bit different delimiters and for that reason the number in this case is 8. Just change the values to get out what you want. To get residuals for different variable just change the grep argument. Finally if you want, you can just combine all your files to a single file with paste, e.g.:

paste p_residuals Ux_residuals Uy_residuals Uz_residuals > residuals

now you can copy the residuals-file to your local computer and use a spreadsheet tool of your choice to plot the residuals. To make it work faster you can create a bash script to do it all. This might sound a bit complex way to do it but this way you have all the raw data for the residuals. I hope this helps.

-Antti

[KateEisenhower]

Originally Posted by Tobi

Hi Kate,

I am not sure but can you access via ssh in a terminal? Then it should be possible to plot the residuals on your computer with common tools like gnuplot, the new foam function (residuals) or pyFoamPlotWatcher.py. I did this on my own cluster a while ago.

Hi Tobi,

Thanks for your answer. Yes, I have access using ssh in a terminal window. I think my question was a bit missleading. I am not even sure if my OS has any GUI. Nethertheless I tried your approach again and got:

QXcbConnection: Could not connect to display

Best regards,

Kate

[KateEisenhower]

Dear antti,

Thank you. I was trying to emphasize the with cli-only access part of my question. So your last paragraph was the most useful for me. To write a custom bash script, was also my first idea. I only thought I was missing something.
Again thanks for your answer.

Best regards,

Kate

Originally Posted by anttiad9000

Hello Kate,

If I understood correctly you do not have access to graphical utilies so you cannot use the GUI for gnuplot. Here is another way you can do it.

The most important thing is that you are logging the simulation to a file with >, e.g. :

icoFoam > log.icoFoam

Then a very straight forward and kind of manual way to do this without using pyFoam is to use 'grep' and combination of grep and cut to get the essential numbers and save them again to a new file, e.g. (this is for foam-extend):

grep "p, Initial residual" log.icoFoam | cut -d ' ' -f 9 | sed 's/,//g' > p_residuals

sed is used to remove the comma after the value, -f 9 means the 9th field from left which will be printed, you can also replace cut with: awk '{print $8}'. It uses a bit different delimiters and for that reason the number in this case is 8. Just change the values to get out what you want. To get residuals for different variable just change the grep argument. Finally if you want, you can just combine all your files to a single file with paste, e.g.:

paste p_residuals Ux_residuals Uy_residuals Uz_residuals > residuals

now you can copy the residuals-file to your local computer and use a spreadsheet tool of your choice to plot the residuals. To make it work faster you can create a bash script to do it all. This might sound a bit complex way to do it but this way you have all the raw data for the residuals. I hope this helps.

-Antti

[LVDH]

http://stackoverflow.com/questions/1...-plotting-tool