1 2 static char help[] = "Tests MatNorm(), MatLUFactor(), MatSolve() and MatSolveAdd().\n\n"; 3 4 #include <petscmat.h> 5 6 int main(int argc, char **args) 7 { 8 Mat C; 9 PetscInt i, j, m = 3, n = 3, Ii, J; 10 PetscBool flg; 11 PetscScalar v; 12 IS perm, iperm; 13 Vec x, u, b, y; 14 PetscReal norm, tol = PETSC_SMALL; 15 MatFactorInfo info; 16 PetscMPIInt size; 17 18 PetscFunctionBeginUser; 19 PetscCall(PetscInitialize(&argc, &args, (char *)0, help)); 20 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size)); 21 PetscCheck(size == 1, PETSC_COMM_WORLD, PETSC_ERR_WRONG_MPI_SIZE, "This is a uniprocessor example only!"); 22 PetscCall(MatCreate(PETSC_COMM_WORLD, &C)); 23 PetscCall(MatSetSizes(C, PETSC_DECIDE, PETSC_DECIDE, m * n, m * n)); 24 PetscCall(MatSetFromOptions(C)); 25 PetscCall(MatSetUp(C)); 26 PetscCall(PetscOptionsHasName(NULL, NULL, "-symmetric", &flg)); 27 if (flg) { /* Treat matrix as symmetric only if we set this flag */ 28 PetscCall(MatSetOption(C, MAT_SYMMETRIC, PETSC_TRUE)); 29 PetscCall(MatSetOption(C, MAT_SYMMETRY_ETERNAL, PETSC_TRUE)); 30 } 31 32 /* Create the matrix for the five point stencil, YET AGAIN */ 33 for (i = 0; i < m; i++) { 34 for (j = 0; j < n; j++) { 35 v = -1.0; 36 Ii = j + n * i; 37 if (i > 0) { 38 J = Ii - n; 39 PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 40 } 41 if (i < m - 1) { 42 J = Ii + n; 43 PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 44 } 45 if (j > 0) { 46 J = Ii - 1; 47 PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 48 } 49 if (j < n - 1) { 50 J = Ii + 1; 51 PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 52 } 53 v = 4.0; 54 PetscCall(MatSetValues(C, 1, &Ii, 1, &Ii, &v, INSERT_VALUES)); 55 } 56 } 57 PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY)); 58 PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY)); 59 PetscCall(MatGetOrdering(C, MATORDERINGRCM, &perm, &iperm)); 60 PetscCall(MatView(C, PETSC_VIEWER_STDOUT_WORLD)); 61 PetscCall(ISView(perm, PETSC_VIEWER_STDOUT_SELF)); 62 PetscCall(VecCreateSeq(PETSC_COMM_SELF, m * n, &u)); 63 PetscCall(VecSet(u, 1.0)); 64 PetscCall(VecDuplicate(u, &x)); 65 PetscCall(VecDuplicate(u, &b)); 66 PetscCall(VecDuplicate(u, &y)); 67 PetscCall(MatMult(C, u, b)); 68 PetscCall(VecCopy(b, y)); 69 PetscCall(VecScale(y, 2.0)); 70 71 PetscCall(MatNorm(C, NORM_FROBENIUS, &norm)); 72 PetscCall(PetscPrintf(PETSC_COMM_SELF, "Frobenius norm of matrix %g\n", (double)norm)); 73 PetscCall(MatNorm(C, NORM_1, &norm)); 74 PetscCall(PetscPrintf(PETSC_COMM_SELF, "One norm of matrix %g\n", (double)norm)); 75 PetscCall(MatNorm(C, NORM_INFINITY, &norm)); 76 PetscCall(PetscPrintf(PETSC_COMM_SELF, "Infinity norm of matrix %g\n", (double)norm)); 77 78 PetscCall(MatFactorInfoInitialize(&info)); 79 info.fill = 2.0; 80 info.dtcol = 0.0; 81 info.zeropivot = 1.e-14; 82 info.pivotinblocks = 1.0; 83 84 PetscCall(MatLUFactor(C, perm, iperm, &info)); 85 86 /* Test MatSolve */ 87 PetscCall(MatSolve(C, b, x)); 88 PetscCall(VecView(b, PETSC_VIEWER_STDOUT_SELF)); 89 PetscCall(VecView(x, PETSC_VIEWER_STDOUT_SELF)); 90 PetscCall(VecAXPY(x, -1.0, u)); 91 PetscCall(VecNorm(x, NORM_2, &norm)); 92 if (norm > tol) PetscCall(PetscPrintf(PETSC_COMM_SELF, "MatSolve: Norm of error %g\n", (double)norm)); 93 94 /* Test MatSolveAdd */ 95 PetscCall(MatSolveAdd(C, b, y, x)); 96 PetscCall(VecAXPY(x, -1.0, y)); 97 PetscCall(VecAXPY(x, -1.0, u)); 98 PetscCall(VecNorm(x, NORM_2, &norm)); 99 if (norm > tol) PetscCall(PetscPrintf(PETSC_COMM_SELF, "MatSolveAdd(): Norm of error %g\n", (double)norm)); 100 101 PetscCall(ISDestroy(&perm)); 102 PetscCall(ISDestroy(&iperm)); 103 PetscCall(VecDestroy(&u)); 104 PetscCall(VecDestroy(&y)); 105 PetscCall(VecDestroy(&b)); 106 PetscCall(VecDestroy(&x)); 107 PetscCall(MatDestroy(&C)); 108 PetscCall(PetscFinalize()); 109 return 0; 110 } 111 112 /*TEST 113 114 test: 115 116 TEST*/ 117