Bernard, The bug is fixed in branch hzhang/fix-elementalSetOption. https://bitbucket.org/petsc/petsc/commits/891a05710665f381fc66132810d0b09973b0e049
It will be merged to petsc-release after night tests. Thanks for reporting it! Hong On Wed, Sep 28, 2016 at 8:04 PM, Hong <[email protected]> wrote: > Bernard: > With your code, I reproduced error and found that the default > MAT_ROW_ORIENTED for MatSetValues() is changed to MAT_COLUMN_ORIENTED. > This is a bug in our library. I'll fix it. > > You can add > MatSetOption(C,MAT_ROW_ORIENTED,PETSC_TRUE); > before 2nd call of matrixC(C,t). > > Thanks for reporting the bug. > > Hong > > Hello, >> >> Here is a trimmed down piece of code that illustrates a strange behaviour >> that I am desperately trying to understand. >> >> The problem is that I would expect successive calls to MatView(C,…) to >> display the same numbers. However, the numbers displayed are different, >> even though the content of the matrix C should be the same. >> >> Any help to resolve this would be appreciated. >> >> Cheers, >> Bernard. >> >> Code: >> ****** >> >> static char help[] = "Elemental test\n\n"; >> >> /*T >> >> T*/ >> >> #include <petscmat.h> >> >> PetscScalar pi=3.141592653589793; >> >> /* Prototypes */ >> PetscErrorCode matrixC(Mat C, PetscScalar t); >> >> #undef __FUNCT__ >> #define __FUNCT__ "main" >> int main(int argc, char **args){ >> >> Mat C; >> >> PetscInt N = 8; >> PetscScalar t=0.1, dt=0.0001; >> PetscErrorCode ierr; >> >> /* parameters */ >> ierr = PetscInitialize(&argc, &args, (char*) 0, help) ;CHKERRQ(ierr); >> >> ierr = MatCreate(PETSC_COMM_WORLD, &C); CHKERRQ(ierr); >> ierr = MatSetSizes(C, PETSC_DECIDE, PETSC_DECIDE, N, N); CHKERRQ(ierr); >> ierr = MatSetType(C, MATELEMENTAL); CHKERRQ(ierr); >> ierr = MatSetFromOptions(C); CHKERRQ(ierr); >> ierr = MatSetUp(C); CHKERRQ(ierr); >> >> ierr=matrixC(C,t); >> ierr = MatView(C,PETSC_VIEWER_STDOUT_WORLD); >> >> ierr=matrixC(C,t); >> ierr = MatView(C,PETSC_VIEWER_STDOUT_WORLD); >> >> ierr = MatDestroy(&C);CHKERRQ(ierr); >> >> ierr = PetscFinalize(); >> >> return ierr; >> } >> >> /* Matrix C*/ >> PetscErrorCode matrixC(Mat C, PetscScalar t){ >> >> PetscErrorCode ierr; >> IS isrows,iscols; >> const PetscInt *rows,*cols; >> PetscScalar *v; >> PetscInt i,j,nrows,ncols; >> PetscInt n,m; >> >> /* Set local matrix entries */ >> ierr = MatGetOwnershipIS(C,&isrows,&iscols);CHKERRQ(ierr); >> ierr = ISGetLocalSize(isrows,&nrows);CHKERRQ(ierr); >> ierr = ISGetIndices(isrows,&rows);CHKERRQ(ierr); >> ierr = ISGetLocalSize(iscols,&ncols);CHKERRQ(ierr); >> ierr = ISGetIndices(iscols,&cols);CHKERRQ(ierr); >> ierr = PetscMalloc1(nrows*ncols,&v);CHKERRQ(ierr); >> >> for (i=0; i<nrows; i++) { >> n=rows[i]; >> for (j=0; j<ncols; j++) { >> m=cols[j]; >> v[i*ncols+j] = -0.5*(exp(-(m+n+1.5)*(m+n+1.5) >> *pi*pi*t)-exp(-(m-n+0.5)*(m-n+0.5)*pi*pi*t)); >> } >> } >> >> ierr = MatSetValues(C,nrows,rows,ncols,cols,v,INSERT_VALUES);CHKERR >> Q(ierr); >> ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); >> ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr); >> ierr = ISRestoreIndices(isrows,&rows);CHKERRQ(ierr); >> ierr = ISRestoreIndices(iscols,&cols);CHKERRQ(ierr); >> ierr = ISDestroy(&isrows);CHKERRQ(ierr); >> ierr = ISDestroy(&iscols);CHKERRQ(ierr); >> ierr = PetscFree(v);CHKERRQ(ierr); >> >> PetscFunctionReturn(0); >> } >> >> Output: >> ******** >> >> mpirun -n 2 ./elemental >> >> Mat Object: 2 MPI processes >> type: elemental >> Elemental matrix (cyclic ordering) >> 0.336403 2.8059e-06 0.0532215 1.04511e-09 0.00104438 >> 0.00104718 0.390672 0.0542687 0.0542687 0.390672 >> 0.389625 0.00104718 0.390669 2.80695e-06 0.0542687 >> 2.80695e-06 0.390672 0.00104718 0.390672 0.0542687 >> 0.0542659 0.0542687 0.390672 0.00104718 0.390672 >> >> Elemental matrix (explicit ordering) >> Mat Object: 2 MPI processes >> type: mpidense >> 3.3640319378153799e-01 5.3221486768492490e-02 1.0443777750910219e-03 >> 2.8059034408741489e-06 1.0451056906250189e-09 >> 3.8962468055003047e-01 3.9066905832512150e-01 5.4268670447024388e-02 >> 1.0471847236375868e-03 2.8069486006233780e-06 >> 5.4265864543583515e-02 3.9067186422856237e-01 3.9067186527366804e-01 >> 5.4268671492184138e-02 1.0471847236916457e-03 >> 1.0471836785318962e-03 5.4268671492130077e-02 3.9067186527372211e-01 >> 3.9067186527372211e-01 5.4268671492184138e-02 >> 2.8069485465647739e-06 1.0471847236916453e-03 5.4268671492184138e-02 >> 3.9067186527372211e-01 3.9067186527372211e-01 >> Mat Object: 2 MPI processes >> type: elemental >> Elemental matrix (cyclic ordering) >> 0.336403 2.8059e-06 0.390672 2.80695e-06 0.00104718 >> 0.0532215 1.04511e-09 0.389625 0.390672 0.0542687 >> 0.00104438 0.390672 0.390669 0.390672 0.0542659 >> 0.00104718 0.0542687 0.0542687 0.0542687 0.390672 >> 0.0542687 0.00104718 2.80695e-06 0.00104718 0.390672 >> >> Elemental matrix (explicit ordering) >> Mat Object: 2 MPI processes >> type: mpidense >> 3.3640319378153799e-01 3.9067186527372211e-01 1.0471847236916453e-03 >> 2.8059034408741489e-06 2.8069486006233780e-06 >> 1.0443777750910219e-03 3.9066905832512150e-01 5.4265864543583515e-02 >> 3.9067186527372211e-01 3.9067186527372211e-01 >> 5.4268671492130077e-02 2.8069485465647739e-06 3.9067186527366804e-01 >> 1.0471847236375868e-03 1.0471847236916457e-03 >> 5.3221486768492490e-02 3.8962468055003047e-01 5.4268671492184138e-02 >> 1.0451056906250189e-09 3.9067186527372211e-01 >> 1.0471836785318962e-03 5.4268670447024388e-02 3.9067186422856237e-01 >> 5.4268671492184138e-02 5.4268671492184138e-02 >> >> >> >> >
