Actual source code: ex68.c


  2: static char help[] = "Tests MatReorderForNonzeroDiagonal().\n\n";

  4: #include <petscmat.h>

  6: int main(int argc, char **argv)
  7: {
  8:   Mat         mat, B, C;
  9:   PetscInt    i, j;
 10:   PetscMPIInt size;
 11:   PetscScalar v;
 12:   IS          isrow, iscol, identity;
 13:   PetscViewer viewer;

 15:   PetscFunctionBeginUser;
 16:   PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));

 18:   /* ------- Assemble matrix, --------- */

 20:   PetscCall(MatCreate(PETSC_COMM_WORLD, &mat));
 21:   PetscCall(MatSetSizes(mat, PETSC_DECIDE, PETSC_DECIDE, 4, 4));
 22:   PetscCall(MatSetFromOptions(mat));
 23:   PetscCall(MatSetUp(mat));

 25:   /* set anti-diagonal of matrix */
 26:   v = 1.0;
 27:   i = 0;
 28:   j = 3;
 29:   PetscCall(MatSetValues(mat, 1, &i, 1, &j, &v, INSERT_VALUES));
 30:   v = 2.0;
 31:   i = 1;
 32:   j = 2;
 33:   PetscCall(MatSetValues(mat, 1, &i, 1, &j, &v, INSERT_VALUES));
 34:   v = 3.0;
 35:   i = 2;
 36:   j = 1;
 37:   PetscCall(MatSetValues(mat, 1, &i, 1, &j, &v, INSERT_VALUES));
 38:   v = 4.0;
 39:   i = 3;
 40:   j = 0;
 41:   PetscCall(MatSetValues(mat, 1, &i, 1, &j, &v, INSERT_VALUES));
 42:   PetscCall(MatAssemblyBegin(mat, MAT_FINAL_ASSEMBLY));
 43:   PetscCall(MatAssemblyEnd(mat, MAT_FINAL_ASSEMBLY));

 45:   PetscCall(PetscViewerASCIIGetStdout(PETSC_COMM_WORLD, &viewer));
 46:   PetscCall(PetscViewerPushFormat(viewer, PETSC_VIEWER_ASCII_DENSE));
 47:   PetscCall(PetscViewerASCIIPrintf(viewer, "Original matrix\n"));
 48:   PetscCall(MatView(mat, viewer));

 50:   PetscCall(MatGetOrdering(mat, MATORDERINGNATURAL, &isrow, &iscol));

 52:   PetscCall(MatPermute(mat, isrow, iscol, &B));
 53:   PetscCall(PetscViewerASCIIPrintf(viewer, "Original matrix permuted by identity\n"));
 54:   PetscCall(MatView(B, viewer));
 55:   PetscCall(MatDestroy(&B));

 57:   PetscCall(MatReorderForNonzeroDiagonal(mat, 1.e-8, isrow, iscol));
 58:   PetscCall(MatPermute(mat, isrow, iscol, &B));
 59:   PetscCall(PetscViewerASCIIPrintf(viewer, "Original matrix permuted by identity + NonzeroDiagonal()\n"));
 60:   PetscCall(MatView(B, viewer));
 61:   PetscCall(PetscViewerASCIIPrintf(viewer, "Row permutation\n"));
 62:   PetscCall(ISView(isrow, viewer));
 63:   PetscCall(PetscViewerASCIIPrintf(viewer, "Column permutation\n"));
 64:   PetscCall(ISView(iscol, viewer));
 65:   PetscCall(MatDestroy(&B));

 67:   PetscCall(ISDestroy(&isrow));
 68:   PetscCall(ISDestroy(&iscol));

 70:   PetscCall(MatGetOrdering(mat, MATORDERINGND, &isrow, &iscol));
 71:   PetscCall(MatPermute(mat, isrow, iscol, &B));
 72:   PetscCall(PetscViewerASCIIPrintf(viewer, "Original matrix permuted by ND\n"));
 73:   PetscCall(MatView(B, viewer));
 74:   PetscCall(MatDestroy(&B));
 75:   PetscCall(PetscViewerASCIIPrintf(viewer, "ND row permutation\n"));
 76:   PetscCall(ISView(isrow, viewer));
 77:   PetscCall(PetscViewerASCIIPrintf(viewer, "ND column permutation\n"));
 78:   PetscCall(ISView(iscol, viewer));

 80:   PetscCall(MatReorderForNonzeroDiagonal(mat, 1.e-8, isrow, iscol));
 81:   PetscCall(MatPermute(mat, isrow, iscol, &B));
 82:   PetscCall(PetscViewerASCIIPrintf(viewer, "Original matrix permuted by ND + NonzeroDiagonal()\n"));
 83:   PetscCall(MatView(B, viewer));
 84:   PetscCall(MatDestroy(&B));
 85:   PetscCall(PetscViewerASCIIPrintf(viewer, "ND + NonzeroDiagonal() row permutation\n"));
 86:   PetscCall(ISView(isrow, viewer));
 87:   PetscCall(PetscViewerASCIIPrintf(viewer, "ND + NonzeroDiagonal() column permutation\n"));
 88:   PetscCall(ISView(iscol, viewer));

 90:   PetscCall(ISDestroy(&isrow));
 91:   PetscCall(ISDestroy(&iscol));

 93:   PetscCall(MatGetOrdering(mat, MATORDERINGRCM, &isrow, &iscol));
 94:   PetscCall(MatPermute(mat, isrow, iscol, &B));
 95:   PetscCall(PetscViewerASCIIPrintf(viewer, "Original matrix permuted by RCM\n"));
 96:   PetscCall(MatView(B, viewer));
 97:   PetscCall(MatDestroy(&B));
 98:   PetscCall(PetscViewerASCIIPrintf(viewer, "RCM row permutation\n"));
 99:   PetscCall(ISView(isrow, viewer));
100:   PetscCall(PetscViewerASCIIPrintf(viewer, "RCM column permutation\n"));
101:   PetscCall(ISView(iscol, viewer));

103:   PetscCall(MatReorderForNonzeroDiagonal(mat, 1.e-8, isrow, iscol));
104:   PetscCall(MatPermute(mat, isrow, iscol, &B));
105:   PetscCall(PetscViewerASCIIPrintf(viewer, "Original matrix permuted by RCM + NonzeroDiagonal()\n"));
106:   PetscCall(MatView(B, viewer));
107:   PetscCall(PetscViewerASCIIPrintf(viewer, "RCM + NonzeroDiagonal() row permutation\n"));
108:   PetscCall(ISView(isrow, viewer));
109:   PetscCall(PetscViewerASCIIPrintf(viewer, "RCM + NonzeroDiagonal() column permutation\n"));
110:   PetscCall(ISView(iscol, viewer));
111:   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
112:   if (size == 1) {
113:     PetscCall(MatSetOption(B, MAT_SYMMETRIC, PETSC_TRUE));
114:     PetscCall(ISCreateStride(PETSC_COMM_SELF, 4, 0, 1, &identity));
115:     PetscCall(MatPermute(B, identity, identity, &C));
116:     PetscCall(MatConvert(C, MATSEQSBAIJ, MAT_INPLACE_MATRIX, &C));
117:     PetscCall(MatDestroy(&C));
118:     PetscCall(ISDestroy(&identity));
119:   }
120:   PetscCall(MatDestroy(&B));
121:   /* Test MatLUFactor(); set diagonal as zeros as requested by PETSc matrix factorization */
122:   for (i = 0; i < 4; i++) {
123:     v = 0.0;
124:     PetscCall(MatSetValues(mat, 1, &i, 1, &i, &v, INSERT_VALUES));
125:   }
126:   PetscCall(MatAssemblyBegin(mat, MAT_FINAL_ASSEMBLY));
127:   PetscCall(MatAssemblyEnd(mat, MAT_FINAL_ASSEMBLY));
128:   PetscCall(MatLUFactor(mat, isrow, iscol, NULL));

130:   /* Free data structures */
131:   PetscCall(ISDestroy(&isrow));
132:   PetscCall(ISDestroy(&iscol));
133:   PetscCall(MatDestroy(&mat));

135:   PetscCall(PetscFinalize());
136:   return 0;
137: }

139: /*TEST

141:    test:

143: TEST*/