https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Vec/VecLoad.html <https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Vec/VecLoad.html> and https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Mat/MatLoad.html <https://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Mat/MatLoad.html> define the simple format.
There are loaders for Matlab and Python distributed with PETSc so for those two languages you do not need to write your own custom loaders. Barry > On Dec 29, 2020, at 12:32 PM, C B <[email protected]> wrote: > > Hello PETSc community ! > > I would like to read in another code a matrix / rhs / sol saved by PETSc. > I am dealing with large matrices and for precision I would like to use the > binary format. > > To save a matrix I am using the following lines (please let me know if I > should make any changes), I am using an old version PETSc 2.1.5 for backward > compatibility. > > ierr = > PetscViewerBinaryOpen(PETSC_COMM_WORLD,filename,PETSC_BINARY_CREATE,&petsc_view);CHKERRQ(ierr); > ierr = VecView(solut,petsc_view);CHKERRQ(ierr); > ierr = PetscViewerDestroy(petsc_view);CHKERRQ(ierr); > > And to save a vector: > > ierr = PetscViewerBinaryOpen(PETSC_COMM_WORLD, filename, PETSC_BINARY_CREATE, > &petsc_view);CHKERRQ(ierr); > ierr = VecView(solut, petsc_view);CHKERRQ(ierr); > ierr = PetscViewerDestroy(petsc_view);CHKERRQ(ierr); > > The files are saved without any problems, and now I need to write the code to > read the binary files. > Please, would anyone point me to the format of these binary files and/or a > code snippet to take as an example ? > > Thank you very much in advance ! > Cheers
