Actual source code: ex162.c
petsc-3.13.6 2020-09-29
1: static char help[] = "Tests MatShift for SeqAIJ matrices with some missing diagonal entries\n\n";
3: #include <petscmat.h>
5: int main(int argc,char **argv)
6: {
7: Mat A;
8: PetscInt coli[4],row;
9: PetscScalar vali[4];
10: PetscErrorCode ierr;
11: PetscMPIInt size;
13: PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
14: MPI_Comm_size(PETSC_COMM_WORLD,&size);
15: if (size != 1) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"This is a uniprocessor example only!");
17: MatCreate(PETSC_COMM_SELF,&A);
18: MatSetSizes(A,4,4,4,4);
19: MatSetType(A,MATSEQAIJ);
20: MatSeqAIJSetPreallocation(A,4,NULL);
22: row = 0; coli[0] = 1; coli[1] = 3; vali[0] = 1.0; vali[1] = 2.0;
23: MatSetValues(A,1,&row,2,coli,vali,ADD_VALUES);
25: 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;
26: MatSetValues(A,1,&row,4,coli,vali,ADD_VALUES);
28: row = 2; coli[0] = 0; coli[1] = 3; vali[0] = 7.0; vali[1] = 8.0;
29: MatSetValues(A,1,&row,2,coli,vali,ADD_VALUES);
31: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
32: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
33: MatView(A,PETSC_VIEWER_STDOUT_WORLD);
35: MatShift(A,0.0);
36: MatView(A,PETSC_VIEWER_STDOUT_WORLD);
38: MatDestroy(&A);
39: PetscFinalize();
40: return ierr;
41: }
44: /*TEST
46: test:
49: TEST*/