1 2 static char help[] = "Tests converting a matrix to another format with MatConvert().\n\n"; 3 4 #include <petscmat.h> 5 6 int main(int argc, char **args) 7 { 8 Mat C, A; 9 PetscInt i, j, m = 5, n = 4, Ii, J; 10 PetscMPIInt rank, size; 11 PetscScalar v; 12 char mtype[256]; 13 14 PetscFunctionBeginUser; 15 PetscCall(PetscInitialize(&argc, &args, (char *)0, help)); 16 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank)); 17 18 /* This example does not work correctly for np > 2 */ 19 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size)); 20 PetscCheck(size <= 2, PETSC_COMM_WORLD, PETSC_ERR_WRONG_MPI_SIZE, "Use np <= 2"); 21 22 /* Create the matrix for the five point stencil, YET AGAIN */ 23 PetscCall(MatCreate(PETSC_COMM_WORLD, &C)); 24 PetscCall(MatSetSizes(C, PETSC_DECIDE, PETSC_DECIDE, m * n, m * n)); 25 PetscCall(MatSetFromOptions(C)); 26 PetscCall(MatSetUp(C)); 27 for (i = 0; i < m; i++) { 28 for (j = 2 * rank; j < 2 * rank + 2; j++) { 29 v = -1.0; 30 Ii = j + n * i; 31 if (i > 0) { 32 J = Ii - n; 33 PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 34 } 35 if (i < m - 1) { 36 J = Ii + n; 37 PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 38 } 39 if (j > 0) { 40 J = Ii - 1; 41 PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 42 } 43 if (j < n - 1) { 44 J = Ii + 1; 45 PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 46 } 47 v = 4.0; 48 PetscCall(MatSetValues(C, 1, &Ii, 1, &Ii, &v, INSERT_VALUES)); 49 } 50 } 51 52 PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY)); 53 PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY)); 54 PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD, PETSC_VIEWER_ASCII_INFO)); 55 PetscCall(MatView(C, PETSC_VIEWER_STDOUT_WORLD)); 56 PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD)); 57 PetscCall(MatView(C, PETSC_VIEWER_STDOUT_WORLD)); 58 59 PetscCall(PetscStrncpy(mtype, MATSAME, sizeof(mtype))); 60 PetscCall(PetscOptionsGetString(NULL, NULL, "-conv_mat_type", mtype, sizeof(mtype), NULL)); 61 PetscCall(MatConvert(C, mtype, MAT_INITIAL_MATRIX, &A)); 62 PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD, PETSC_VIEWER_ASCII_INFO)); 63 PetscCall(MatView(A, PETSC_VIEWER_STDOUT_WORLD)); 64 PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD)); 65 PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD, PETSC_VIEWER_ASCII_IMPL)); 66 PetscCall(MatView(A, PETSC_VIEWER_STDOUT_WORLD)); 67 PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD)); 68 69 /* Free data structures */ 70 PetscCall(MatDestroy(&A)); 71 PetscCall(MatDestroy(&C)); 72 73 PetscCall(PetscFinalize()); 74 return 0; 75 } 76 77 /*TEST 78 79 test: 80 args: -conv_mat_type seqaij 81 82 TEST*/ 83