xref: /petsc/src/mat/tests/ex162.c (revision daa037dfd3c3bec8dc8659548d2b20b07c1dc6de)
1 static char help[] = "Tests MatShift for SeqAIJ matrices with some missing diagonal entries\n\n";
2 
3 #include <petscmat.h>
4 
5 int main(int argc,char **argv)
6 {
7   Mat                  A;
8   PetscInt             coli[4],row;
9   PetscScalar          vali[4];
10   PetscMPIInt          size;
11 
12   PetscCall(PetscInitialize(&argc,&argv,(char*)0,help));
13   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size));
14   PetscCheck(size == 1,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"This is a uniprocessor example only!");
15 
16   PetscCall(MatCreate(PETSC_COMM_SELF,&A));
17   PetscCall(MatSetSizes(A,4,4,4,4));
18   PetscCall(MatSetType(A,MATSEQAIJ));
19   PetscCall(MatSeqAIJSetPreallocation(A,4,NULL));
20 
21   row = 0; coli[0] = 1; coli[1] = 3; vali[0] = 1.0; vali[1] = 2.0;
22   PetscCall(MatSetValues(A,1,&row,2,coli,vali,ADD_VALUES));
23 
24   row = 1; coli[0] = 0; coli[1] = 1; coli[2] = 2; coli[3] = 3; vali[0] = 3.0; vali[1] = 4.0; vali[2] = 5.0; vali[3] = 6.0;
25   PetscCall(MatSetValues(A,1,&row,4,coli,vali,ADD_VALUES));
26 
27   row = 2; coli[0] = 0; coli[1] = 3; vali[0] = 7.0; vali[1] = 8.0;
28   PetscCall(MatSetValues(A,1,&row,2,coli,vali,ADD_VALUES));
29 
30   PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
31   PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));
32   PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD));
33 
34   PetscCall(MatShift(A,0.0));
35   PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD));
36 
37   PetscCall(MatDestroy(&A));
38   PetscCall(PetscFinalize());
39   return 0;
40 }
41 
42 /*TEST
43 
44    test:
45 
46 TEST*/
47