> On Mar 27, 2015, at 11:14 AM, Klaus Kaiser <kai...@igpm.rwth-aachen.de> wrote: > > Hallo Barry, > > I think you're right, but this is the setup I used for more than a year, so I > first want to check if there is an error in my code and then switch with an > correct code to a newer version when I do have the time for the installation. > > Is the faster symbolic MatAXPY for the DIFFERENT_NONZERO_STRUCTURE flag > faster than using SAME_NONZERO_STRUCTURE?
No > > Best and Thanks a lot > > Klaus > > On 03/27/2015 04:57 PM, Barry Smith wrote: >> Klaus, >> >> You would really benefit by upgrading to PETSc 3.5.3, we added much >> faster symbolic MatAXPY() for the DIFFERENT_NONZERO_STRUCTURE flag. Plus it >> is much easier for us to support the newest version. >> >> Barry >> >>> On Mar 27, 2015, at 9:48 AM, Klaus Kaiser <kai...@igpm.rwth-aachen.de> >>> wrote: >>> >>> Hallo, >>> >>> I have a strange behavior in my code concerning the function MatAXPY. I >>> create 3 different Matrices >>> >>> ierr = MatCreateBAIJ(PETSC_COMM_WORLD, block_size, local_size, >>> local_size, system_size, system_size, 0, d_nnz, 0, o_nnz,&A); >>> ierr = MatSetOption(A,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_TRUE); >>> ierr = MatSetOption(A,MAT_KEEP_NONZERO_PATTERN,PETSC_TRUE); >>> ierr = MatSetOption(A,MAT_IGNORE_OFF_PROC_ENTRIES,PETSC_TRUE); >>> >>> ierr = MatCreateBAIJ(PETSC_COMM_WORLD, block_size, local_size, >>> local_size, system_size, system_size, 0, d_nnz, 0, o_nnz,&At); >>> ierr = MatSetOption(At,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_TRUE); >>> ierr = MatSetOption(At,MAT_KEEP_NONZERO_PATTERN,PETSC_TRUE); >>> ierr = MatSetOption(At,MAT_IGNORE_OFF_PROC_ENTRIES,PETSC_TRUE); >>> >>> ierr = MatCreateBAIJ(PETSC_COMM_WORLD, block_size, local_size, >>> local_size, system_size, system_size, 0, d_nnz, 0, o_nnz,&Ah); >>> ierr = MatSetOption(Ah,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_TRUE); >>> ierr = MatSetOption(Ah,MAT_KEEP_NONZERO_PATTERN,PETSC_TRUE); >>> ierr = MatSetOption(Ah,MAT_IGNORE_OFF_PROC_ENTRIES,PETSC_TRUE); >>> >>> and want to sum these three matrixes with different factors. First I fill >>> the Matrix A with some values, and duplicate the structure of A to the >>> other two matrices: >>> >>> MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY); >>> MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY); >>> MatDuplicate(A,MAT_DO_NOT_COPY_VALUES,&Ah); >>> MatDuplicate(A,MAT_DO_NOT_COPY_VALUES,&At); >>> MatAssemblyBegin(Ah,MAT_FINAL_ASSEMBLY); >>> MatAssemblyEnd(Ah,MAT_FINAL_ASSEMBLY); >>> MatAssemblyBegin(At,MAT_FINAL_ASSEMBLY); >>> MatAssemblyEnd(At,MAT_FINAL_ASSEMBLY); >>> >>> After this I fill the matrices At and Ah with some other values, which are >>> not beside the non zero structure (I also tried with just copying the >>> Matrix A). Now after another MatAssembly I want to add these Matrices in >>> the form A+c*(Ah+d*At): >>> >>> MatAXPY(Ah,c,At,SAME_NONZERO_PATTERN); >>> MatAXPY(A,d,Ah,SAME_NONZERO_PATTERN); >>> >>> When I run the method with mpi and one core everything works fine. Starting >>> the same method with more cores, the sum of the matrices fails. It seems >>> like some values are added correctly and many values are missed. Using >>> DIFFERENT_NONZERO_STRUCTURE leads to the right behavior in the multi-core >>> case, but is very slow. I checked with a viewer if all matrices have the >>> same nonzero structure and this is the case. >>> >>> Does anyone know why this fails, or do I have made any wrong thoughts? >>> >>> I'm corrently working with a petsc version (Petsc Release Version 3.3.0, >>> Patch 5, Sat Dec 1 15:10:41 CST 2012), I looked into the changelogs up to >>> the current version and did not find any note about MatAXPY or MatAYPX. >>> >>> >>> Best and Thanks a lot for your help >>> >>> Klaus >>> >
