Global solution with PETSc

That works perfectly, thank you. I’ve been reviewing the other active thread here and now see that the createMat command is common to the two examples you had mentioned at the top that specifically gather the results at the end of the program.

As a followup question (maybe better moved to the below mentioned thread if more pertinent), I notice that the file output of this now matches the description of the output files of another user when they were using an older version of one of the examples and generated a single PVD file and four VTU files. The suggestion you gave made use of a revised version of that example which made use of the line

export("sol_stokes_3d_io", Th, sol, orderAndName, comm);

and it looks like that fixed the issue for them. In the most recent version of the example, that line has been again revised to now read:

savevtk("stokes-io-3d.vtu", Th, [u, uB, uC], uD, order = fforder, dataname = "velocity pressure");

Is it advisable to switch back to the earlier export command to create a single VTU file as the output, or is there a way to alter my current version of the code to do so?

stokes-3d-PETScagain.edp (2.0 KB)