Thanks I've tried the first option, I get this compilation error
undefined reference to `matcreatesubmatrices_' My PETSc version is 3.7.5, is this a feature of newer versions? Ivano Il giorno ven 16 apr 2021 alle ore 16:06 Matthew Knepley <[email protected]> ha scritto: > On Fri, Apr 16, 2021 at 9:46 AM Ivano Barletta <[email protected]> > wrote: > >> Dear all, >> >> I have an MPI FEM application with an elliptic problem that I >> solve with PETSc. For debugging purposes I want to >> let the master process to solve the global system. >> >> Is there any simple way in PETSc to gather the distributed matrix >> (the type is MATMPIAIJ) on a single MPI process? >> > > You could use > > > https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Mat/MatCreateSubMatrices.html > > to extract a single, serial matrix on process 0. However, you can do this > with the solver automatically using > > > https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/PC/PCTELESCOPE.html > > If you have the memory, you can do this more simply with > > > https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/PC/PCREDUNDANT.html > > Thanks, > > Matt > > >> Thanks, >> Ivano >> >> >> > > -- > What most experimenters take for granted before they begin their > experiments is infinitely more interesting than any results to which their > experiments lead. > -- Norbert Wiener > > https://www.cse.buffalo.edu/~knepley/ > <http://www.cse.buffalo.edu/~knepley/> >
