xref: /petsc/src/mat/tests/ex68.c (revision ebead697dbf761eb322f829370bbe90b3bd93fa3)
1 
2 static char help[] = "Tests MatReorderForNonzeroDiagonal().\n\n";
3 
4 #include <petscmat.h>
5 
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;
14 
15   PetscFunctionBeginUser;
16   PetscCall(PetscInitialize(&argc,&argv,(char*)0,help));
17 
18   /* ------- Assemble matrix, --------- */
19 
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));
24 
25   /* set anti-diagonal of matrix */
26   v    = 1.0;
27   i    = 0; j = 3;
28   PetscCall(MatSetValues(mat,1,&i,1,&j,&v,INSERT_VALUES));
29   v    = 2.0;
30   i    = 1; j = 2;
31   PetscCall(MatSetValues(mat,1,&i,1,&j,&v,INSERT_VALUES));
32   v    = 3.0;
33   i    = 2; j = 1;
34   PetscCall(MatSetValues(mat,1,&i,1,&j,&v,INSERT_VALUES));
35   v    = 4.0;
36   i    = 3; j = 0;
37   PetscCall(MatSetValues(mat,1,&i,1,&j,&v,INSERT_VALUES));
38   PetscCall(MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY));
39   PetscCall(MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY));
40 
41   PetscCall(PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer));
42   PetscCall(PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_DENSE));
43   PetscCall(PetscViewerASCIIPrintf(viewer,"Original matrix\n"));
44   PetscCall(MatView(mat,viewer));
45 
46   PetscCall(MatGetOrdering(mat,MATORDERINGNATURAL,&isrow,&iscol));
47 
48   PetscCall(MatPermute(mat,isrow,iscol,&B));
49   PetscCall(PetscViewerASCIIPrintf(viewer,"Original matrix permuted by identity\n"));
50   PetscCall(MatView(B,viewer));
51   PetscCall(MatDestroy(&B));
52 
53   PetscCall(MatReorderForNonzeroDiagonal(mat,1.e-8,isrow,iscol));
54   PetscCall(MatPermute(mat,isrow,iscol,&B));
55   PetscCall(PetscViewerASCIIPrintf(viewer,"Original matrix permuted by identity + NonzeroDiagonal()\n"));
56   PetscCall(MatView(B,viewer));
57   PetscCall(PetscViewerASCIIPrintf(viewer,"Row permutation\n"));
58   PetscCall(ISView(isrow,viewer));
59   PetscCall(PetscViewerASCIIPrintf(viewer,"Column permutation\n"));
60   PetscCall(ISView(iscol,viewer));
61   PetscCall(MatDestroy(&B));
62 
63   PetscCall(ISDestroy(&isrow));
64   PetscCall(ISDestroy(&iscol));
65 
66   PetscCall(MatGetOrdering(mat,MATORDERINGND,&isrow,&iscol));
67   PetscCall(MatPermute(mat,isrow,iscol,&B));
68   PetscCall(PetscViewerASCIIPrintf(viewer,"Original matrix permuted by ND\n"));
69   PetscCall(MatView(B,viewer));
70   PetscCall(MatDestroy(&B));
71   PetscCall(PetscViewerASCIIPrintf(viewer,"ND row permutation\n"));
72   PetscCall(ISView(isrow,viewer));
73   PetscCall(PetscViewerASCIIPrintf(viewer,"ND column permutation\n"));
74   PetscCall(ISView(iscol,viewer));
75 
76   PetscCall(MatReorderForNonzeroDiagonal(mat,1.e-8,isrow,iscol));
77   PetscCall(MatPermute(mat,isrow,iscol,&B));
78   PetscCall(PetscViewerASCIIPrintf(viewer,"Original matrix permuted by ND + NonzeroDiagonal()\n"));
79   PetscCall(MatView(B,viewer));
80   PetscCall(MatDestroy(&B));
81   PetscCall(PetscViewerASCIIPrintf(viewer,"ND + NonzeroDiagonal() row permutation\n"));
82   PetscCall(ISView(isrow,viewer));
83   PetscCall(PetscViewerASCIIPrintf(viewer,"ND + NonzeroDiagonal() column permutation\n"));
84   PetscCall(ISView(iscol,viewer));
85 
86   PetscCall(ISDestroy(&isrow));
87   PetscCall(ISDestroy(&iscol));
88 
89   PetscCall(MatGetOrdering(mat,MATORDERINGRCM,&isrow,&iscol));
90   PetscCall(MatPermute(mat,isrow,iscol,&B));
91   PetscCall(PetscViewerASCIIPrintf(viewer,"Original matrix permuted by RCM\n"));
92   PetscCall(MatView(B,viewer));
93   PetscCall(MatDestroy(&B));
94   PetscCall(PetscViewerASCIIPrintf(viewer,"RCM row permutation\n"));
95   PetscCall(ISView(isrow,viewer));
96   PetscCall(PetscViewerASCIIPrintf(viewer,"RCM column permutation\n"));
97   PetscCall(ISView(iscol,viewer));
98 
99   PetscCall(MatReorderForNonzeroDiagonal(mat,1.e-8,isrow,iscol));
100   PetscCall(MatPermute(mat,isrow,iscol,&B));
101   PetscCall(PetscViewerASCIIPrintf(viewer,"Original matrix permuted by RCM + NonzeroDiagonal()\n"));
102   PetscCall(MatView(B,viewer));
103   PetscCall(PetscViewerASCIIPrintf(viewer,"RCM + NonzeroDiagonal() row permutation\n"));
104   PetscCall(ISView(isrow,viewer));
105   PetscCall(PetscViewerASCIIPrintf(viewer,"RCM + NonzeroDiagonal() column permutation\n"));
106   PetscCall(ISView(iscol,viewer));
107   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size));
108   if (size == 1) {
109     PetscCall(MatSetOption(B,MAT_SYMMETRIC,PETSC_TRUE));
110     PetscCall(ISCreateStride(PETSC_COMM_SELF,4,0,1,&identity));
111     PetscCall(MatPermute(B,identity,identity,&C));
112     PetscCall(MatConvert(C,MATSEQSBAIJ,MAT_INPLACE_MATRIX,&C));
113     PetscCall(MatDestroy(&C));
114     PetscCall(ISDestroy(&identity));
115   }
116   PetscCall(MatDestroy(&B));
117   /* Test MatLUFactor(); set diagonal as zeros as requested by PETSc matrix factorization */
118   for (i=0; i<4; i++) {
119     v = 0.0;
120     PetscCall(MatSetValues(mat,1,&i,1,&i,&v,INSERT_VALUES));
121   }
122   PetscCall(MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY));
123   PetscCall(MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY));
124   PetscCall(MatLUFactor(mat,isrow,iscol,NULL));
125 
126   /* Free data structures */
127   PetscCall(ISDestroy(&isrow));
128   PetscCall(ISDestroy(&iscol));
129   PetscCall(MatDestroy(&mat));
130 
131   PetscCall(PetscFinalize());
132   return 0;
133 }
134 
135 /*TEST
136 
137    test:
138 
139 TEST*/
140