You want to look at example codes and docs ( https://urldefense.us/v3/__https://petsc.org/release/manualpages/PetscSF/VecScatterCreate/__;!!G_uCfscf7eWS!ZfPM2-JGiNd8Yo2xIkHZlQtcjvcJFjXXbMbQPIZ3C5d-RVC-yfvFjoiEm5yaWLcKxfLTPhKkdLX9BM2atRAJ6eg$ ) but I am guessing global_vec and local_vec do not have the same communicator.
Mark On Sat, Dec 7, 2024 at 9:50 PM Qiyue Lu <qiyue...@gmail.com> wrote: > Hello, > I am trying to fetch 12 entries from a distributed vector global_vec and > put them into a local vector on each process. > > IS is_source, is_dest; > ISCreateGeneral(PETSC_COMM_SELF, 12, idx_global, PETSC_COPY_VALUES, & > is_source); > ISCreateGeneral(PETSC_COMM_SELF, 12, idx_local, PETSC_COPY_VALUES, & > is_dest); > Vec local_vec; > VecCreate(PETSC_COMM_SELF, &local_vec); > VecSetSizes(local_vec, PETSC_DECIDE, 12); > VecSetType(local_vec, VECSEQ); > VecScatter scat; > VecScatterCreate(global_vec, is_source, local_vec, is_dest, &scat); > > > I create the local vector as sequential. However, the last two lines which > create a scatter object, will cause more than half processes to hang and no > error pops out. > > Does the scatter have to be VECMPI to VECMPI and cannot VECMPI to VECSEQ? > > Thanks, > Qiyue Lu >
