Some kind of graphics issue

[Arash Pourakaberian]

Dear Developers,

I use EDM for virtual environment management. Ubuntu 18.04 64bit is the OS. I installed petsc4py as described in https://pypi.org/project/petsc4py/ using pip. When I run poisson2d demo I get a warning says: "PETSc installed without X windows on this machine proceeding without graphics" and doesn't show the outputs. Then, I installed PETSc (by instructions here: https://www.mcs.anl.gov/petsc/documentation/installation.html) on the machine and this warning eliminated and everything was OK (I think the problem was libx11 that was not installed). Now again there is problem with petsc.viewers but it does not show any warnings. When I run the poisson2d or bratu2d demo it shows all outputs (matplotlib+petsc.viewer) but the ones plotted by petsc.viewer wipes out completely less than a second when I run with ipython or shows white window when is run with spyder!

Thanks in advance for your help

[Lisandro Dalcin]

The X11 viewers are quite limited. You should have the X11 development package installed at the time PETSc is configured and built. The graphics windows are kept open just until the process that opened them ends. The command line option -draw_pause can control how long these X11 windows are kept alive. Try -draw_pause -2, this will block the Python process from finishing, then you can click/close the window to finish. Try also -draw_pause -1, this will block the process until you click on the X11 window.

[Arash Pourakaberian]

Thanks for the comment. The issue was not with petsc but gnome-shell-extensions (checked system crashes and saw 7 crash files related to gnome-shell!). I removed them and petsc works pretty nice now.