Dear developers Thank you for your explanation.
But I should use the MatCreateSeqDense because I want to use the MatMatSolve that B matrix must be a SeqDense matrix. Using MatMatSolve is an inevitable part of my code. Could you give me a comment to avoid this error? Best, Seung Lee Kwon 2023년 5월 3일 (수) 오후 7:30, Matthew Knepley <[email protected]>님이 작성: > On Wed, May 3, 2023 at 6:05 AM 권승리 / 학생 / 항공우주공학과 <[email protected]> > wrote: > >> Dear developers >> >> I'm trying to use parallel computing and I ran the command 'mpirun -np 4 >> ./app' >> >> In this case, there are two problems. >> >> *First,* I encountered error message >> /// >> [0]PETSC ERROR: [1]PETSC ERROR: --------------------- Error Message >> -------------------------------------------------------------- >> [1]PETSC ERROR: Invalid argument >> [1]PETSC ERROR: Comm must be of size 1 >> /// >> The code on the error position is >> MatCreateSeqDense(PETSC_COMM_SELF, nns, ns, NULL, &Kns)); >> > > 1) "Seq" means sequential, that is "not parallel". > > 2) This line should still be fine since PETSC_COMM_SELF is a serial > communicator > > 3) You should be checking the error code for each call, maybe using the > CHKERRQ() macro > > 4) Please always send the entire error message, not a snippet > > THanks > > Matt > > >> Could "MatCreateSeqDense" not be used in parallel computing? >> >> *Second*, the same error message is repeated as many times as the number >> of cores. >> if I use command -np 4, then the error message is repeated 4 times. >> Could you recommend some advice related to this? >> >> Best, >> Seung Lee Kwon >> >> -- >> Seung Lee Kwon, Ph.D.Candidate >> Aerospace Structures and Materials Laboratory >> Department of Mechanical and Aerospace Engineering >> Seoul National University >> Building 300 Rm 503, Gwanak-ro 1, Gwanak-gu, Seoul, South Korea, 08826 >> E-mail : [email protected] >> Office : +82-2-880-7389 >> C. P : +82-10-4695-1062 >> > > > -- > 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/> > -- Seung Lee Kwon, Ph.D.Candidate Aerospace Structures and Materials Laboratory Department of Mechanical and Aerospace Engineering Seoul National University Building 300 Rm 503, Gwanak-ro 1, Gwanak-gu, Seoul, South Korea, 08826 E-mail : [email protected] Office : +82-2-880-7389 C. P : +82-10-4695-1062
