xref: /petsc/src/mat/tests/ex12.c (revision 6ffe77eaecce1557e50d00ca5347a7f48e598865)
1 
2 static char help[] = "Tests the use of MatZeroRows() for parallel matrices.\n\
3 This example also tests the use of MatDuplicate() for both MPIAIJ and MPIBAIJ matrices";
4 
5 #include <petscmat.h>
6 
7 extern PetscErrorCode TestMatZeroRows_Basic(Mat,IS,PetscScalar);
8 extern PetscErrorCode TestMatZeroRows_with_no_allocation(Mat,IS,PetscScalar);
9 
10 int main(int argc,char **args)
11 {
12   Mat            A;
13   PetscInt       i,j,m = 3,n,Ii,J,Imax;
14   PetscMPIInt    rank,size;
15   PetscScalar    v,diag=-4.0;
16   IS             is;
17 
18   PetscCall(PetscInitialize(&argc,&args,(char*)0,help));
19   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank));
20   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size));
21   n    = 2*size;
22 
23   /* create A Square matrix for the five point stencil,YET AGAIN*/
24   PetscCall(MatCreate(PETSC_COMM_WORLD,&A));
25   PetscCall(MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n));
26   PetscCall(MatSetFromOptions(A));
27   PetscCall(MatSetUp(A));
28   for (i=0; i<m; i++) {
29     for (j=2*rank; j<2*rank+2; j++) {
30       v = -1.0;  Ii = j + n*i;
31       if (i>0)   {J = Ii - n; PetscCall(MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES));}
32       if (i<m-1) {J = Ii + n; PetscCall(MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES));}
33       if (j>0)   {J = Ii - 1; PetscCall(MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES));}
34       if (j<n-1) {J = Ii + 1; PetscCall(MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES));}
35       v = 4.0; PetscCall(MatSetValues(A,1,&Ii,1,&Ii,&v,INSERT_VALUES));
36     }
37   }
38   PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
39   PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));
40 
41   /* Create AN IS required by MatZeroRows() */
42   Imax = n*rank; if (Imax>= n*m -m - 1) Imax = m*n - m - 1;
43   PetscCall(ISCreateStride(PETSC_COMM_SELF,m,Imax,1,&is));
44 
45   PetscCall(TestMatZeroRows_Basic(A,is,0.0));
46   PetscCall(TestMatZeroRows_Basic(A,is,diag));
47 
48   PetscCall(TestMatZeroRows_with_no_allocation(A,is,0.0));
49   PetscCall(TestMatZeroRows_with_no_allocation(A,is,diag));
50 
51   PetscCall(MatDestroy(&A));
52 
53   /* Now Create a rectangular matrix with five point stencil (app)
54    n+size is used so that this dimension is always divisible by size.
55    This way, we can always use bs = size for any number of procs */
56   PetscCall(MatCreate(PETSC_COMM_WORLD,&A));
57   PetscCall(MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,m*n,m*(n+size)));
58   PetscCall(MatSetFromOptions(A));
59   PetscCall(MatSetUp(A));
60   for (i=0; i<m; i++) {
61     for (j=2*rank; j<2*rank+2; j++) {
62       v = -1.0;  Ii = j + n*i;
63       if (i>0)   {J = Ii - n; PetscCall(MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES));}
64       if (i<m-1) {J = Ii + n; PetscCall(MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES));}
65       if (j>0)   {J = Ii - 1; PetscCall(MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES));}
66       if (j<n+size-1) {J = Ii + 1; PetscCall(MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES));}
67       v = 4.0; PetscCall(MatSetValues(A,1,&Ii,1,&Ii,&v,INSERT_VALUES));
68     }
69   }
70   PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
71   PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));
72 
73   PetscCall(TestMatZeroRows_Basic(A,is,0.0));
74   PetscCall(TestMatZeroRows_Basic(A,is,diag));
75 
76   PetscCall(MatDestroy(&A));
77   PetscCall(ISDestroy(&is));
78   PetscCall(PetscFinalize());
79   return 0;
80 }
81 
82 PetscErrorCode TestMatZeroRows_Basic(Mat A,IS is,PetscScalar diag)
83 {
84   Mat            B;
85   PetscBool      keepnonzeropattern;
86 
87   /* Now copy A into B, and test it with MatZeroRows() */
88   PetscCall(MatDuplicate(A,MAT_COPY_VALUES,&B));
89 
90   PetscCall(PetscOptionsHasName(NULL,NULL,"-keep_nonzero_pattern",&keepnonzeropattern));
91   if (keepnonzeropattern) {
92     PetscCall(MatSetOption(B,MAT_KEEP_NONZERO_PATTERN,PETSC_TRUE));
93   }
94 
95   PetscCall(MatZeroRowsIS(B,is,diag,0,0));
96   PetscCall(MatView(B,PETSC_VIEWER_STDOUT_WORLD));
97   PetscCall(MatDestroy(&B));
98   return 0;
99 }
100 
101 PetscErrorCode TestMatZeroRows_with_no_allocation(Mat A,IS is,PetscScalar diag)
102 {
103   Mat            B;
104 
105   /* Now copy A into B, and test it with MatZeroRows() */
106   PetscCall(MatDuplicate(A,MAT_COPY_VALUES,&B));
107   /* Set this flag after assembly. This way, it affects only MatZeroRows() */
108   PetscCall(MatSetOption(B,MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_TRUE));
109 
110   PetscCall(MatZeroRowsIS(B,is,diag,0,0));
111   PetscCall(MatView(B,PETSC_VIEWER_STDOUT_WORLD));
112   PetscCall(MatDestroy(&B));
113   return 0;
114 }
115 
116 /*TEST
117 
118    test:
119       nsize: 2
120       filter: grep -v " MPI process"
121 
122    test:
123       suffix: 2
124       nsize: 3
125       args: -mat_type mpibaij -mat_block_size 3
126       filter: grep -v " MPI process"
127 
128    test:
129       suffix: 3
130       nsize: 3
131       args: -mat_type mpiaij -keep_nonzero_pattern
132       filter: grep -v " MPI process"
133 
134    test:
135       suffix: 4
136       nsize: 3
137       args: -keep_nonzero_pattern -mat_type mpibaij -mat_block_size 3
138       filter: grep -v " MPI process"
139 
140 TEST*/
141