Actual source code: ex162.c

  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:   PetscMPIInt size;

 13:   PetscInitialize(&argc, &argv, (char *)0, help);
 14:   MPI_Comm_size(PETSC_COMM_WORLD, &size);

 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;
 23:   coli[0] = 1;
 24:   coli[1] = 3;
 25:   vali[0] = 1.0;
 26:   vali[1] = 2.0;
 27:   MatSetValues(A, 1, &row, 2, coli, vali, ADD_VALUES);

 29:   row     = 1;
 30:   coli[0] = 0;
 31:   coli[1] = 1;
 32:   coli[2] = 2;
 33:   coli[3] = 3;
 34:   vali[0] = 3.0;
 35:   vali[1] = 4.0;
 36:   vali[2] = 5.0;
 37:   vali[3] = 6.0;
 38:   MatSetValues(A, 1, &row, 4, coli, vali, ADD_VALUES);

 40:   row     = 2;
 41:   coli[0] = 0;
 42:   coli[1] = 3;
 43:   vali[0] = 7.0;
 44:   vali[1] = 8.0;
 45:   MatSetValues(A, 1, &row, 2, coli, vali, ADD_VALUES);

 47:   MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY);
 48:   MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY);
 49:   MatView(A, PETSC_VIEWER_STDOUT_WORLD);

 51:   MatShift(A, 0.0);
 52:   MatView(A, PETSC_VIEWER_STDOUT_WORLD);

 54:   MatDestroy(&A);
 55:   PetscFinalize();
 56:   return 0;
 57: }

 59: /*TEST

 61:    test:

 63: TEST*/