src/mat/tests/ex9.c and other examples in that directory use it.
> On Mar 17, 2023, at 11:05 AM, user_gong Kim <ksi2...@gmail.com> wrote: > > PETSC_COMM_SELF generates an error in more than 2 processes. It should not > > I would like to use the other method you said, matcreateredundantmatrix. > However, there is no example in the manual. Can you give an example using > this function? > > > > 2023년 3월 17일 (금) 오후 11:53, Barry Smith <bsm...@petsc.dev > <mailto:bsm...@petsc.dev>>님이 작성: >> >> Use >> >>>> MatCreate(PETSC_COMM_SELF, &mat); >>>> PetscViewerBinaryOpen(PETSC_COMM_SELF, "mat.bin", FILE_MODE_READ, >>>> &viewer); >> >> >> If it one program running that both views and loads the matrix you can >> use MatCreateRedundantMatrix() to reproduce the entire matrix on each MPI >> rank. It is better than using the filesystem to do it. >> >> >>> On Mar 17, 2023, at 9:45 AM, user_gong Kim <ksi2...@gmail.com >>> <mailto:ksi2...@gmail.com>> wrote: >>> >>> Following your comments, I did an test. >>> However, if I run the application in parallel. >>> In all processes, it is not possible to obtain values at all positions in >>> the matrix through MatGetValue. >>> As in the previous case of saving in binary, it is read in parallel divided >>> form. >>> Is it impossible to want to get the all value in the whole process? >>> >>> >>> Thanks, >>> Hyung Kim >>> >>> 2023년 3월 17일 (금) 오후 7:35, Matthew Knepley <knep...@gmail.com >>> <mailto:knep...@gmail.com>>님이 작성: >>>> On Fri, Mar 17, 2023 at 5:51 AM user_gong Kim <ksi2...@gmail.com >>>> <mailto:ksi2...@gmail.com>> wrote: >>>>> Hello, >>>>> >>>>> >>>>> I have 2 questions about MatView. >>>>> >>>>> >>>>> 1. I would like to ask if the process below is possible. >>>>> When running in parallel, is it possible to make the matrix of the mpiaij >>>>> format into a txt file, output it, and read it again so that the entire >>>>> process has the same matrix? >>>>> >>>> No. However, you can do this with a binary viewer. I suggest using >>>> >>>> MatViewFromOptions(mat, NULL, "-my_view"); >>>> >>>> and then the command line argument >>>> >>>> -my_view binary:mat.bin >>>> >>>> and then you can read this in using >>>> >>>> MatCreate(PETSC_COMM_WORLD, &mat); >>>> PetscViewerBinaryOpen(PETSC_COMM_WORLD, "mat.bin", FILE_MODE_READ, >>>> &viewer); >>>> MatLoad(mat, viewer); >>>> ViewerDestroy(&viewer); >>>> >>>> THanks, >>>> >>>> Matt >>>> >>>> >>>>> 2. If possible, please let me know which function can be used to >>>>> create a txt file and how to read the txt file. >>>>> >>>>> >>>>> Thanks, >>>>> >>>>> Hyung Kim >>>>> >>>> >>>> >>>> -- >>>> 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/> >>
