2: static char help[] ="Tests MatPtAP() \n";

  4: #include <petscmat.h>

  6: /*
  7:  * This is an extremely simple example to test MatPtAP. It is very useful when developing and debugging the code.
  8:  *
  9:  * A =

 11:    1   2   0   4
 12:    0   1   2   0
 13:    2   0   4   0
 14:    0   1   2   1
 15:  *
 16:  *
 17:  *
 18:  * P =

 20:    1.00000   0.00000
 21:    0.30000   0.50000
 22:    0.00000   0.80000
 23:    0.90000   0.00000
 24:  *
 25:  *
 26:  *AP =
 27:  *
 28:  * 5.20000   1.00000
 29:    0.30000   2.10000
 30:    2.00000   3.20000
 31:    1.20000   2.10000
 32:  *
 33:  * PT =

 35:    1.00000   0.30000   0.00000   0.90000
 36:    0.00000   0.50000   0.80000   0.00000

 38:  *
 39:  * C =

 41:    6.3700   3.5200
 42:    1.7500   3.6100
 43:  *
 44:  * */

 46: int main(int argc,char **argv)
 47: {
 49:   Mat            A,P,PtAP;
 50:   PetscInt       i1[] = {0, 3, 5}, i2[] = {0,2,5};
 51:   PetscInt       j1[] = {0, 1, 3, 1, 2}, j2[] = {0, 2, 1, 2, 3};
 52:   PetscScalar    a1[] = {1, 2, 4, 1, 2}, a2[] = {2, 4, 1, 2, 1};
 53:   PetscInt       pi1[] = {0,1,3}, pi2[] = {0,1,2};
 54:   PetscInt       pj1[] = {0, 0, 1}, pj2[] = {1,0};
 55:   PetscScalar    pa1[] = {1, 0.3, 0.5}, pa2[] = {0.8, 0.9};
 56:   MPI_Comm       comm;
 57:   PetscMPIInt    rank,size;

 59:   PetscInitialize(&argc,&argv,NULL,help);if (ierr) return ierr;
 60:   comm = PETSC_COMM_WORLD;
 61:   MPI_Comm_rank(comm,&rank);
 62:   MPI_Comm_size(comm,&size);
 63:   if (size != 2) SETERRQ(comm,PETSC_ERR_ARG_INCOMP,"You have to use two processor cores to run this example \n");
 64:   MatCreateMPIAIJWithArrays(comm,2,2,PETSC_DETERMINE,PETSC_DETERMINE,rank? i2:i1,rank? j2:j1,rank? a2:a1,&A);
 65:   MatCreateMPIAIJWithArrays(comm,2,1,PETSC_DETERMINE,PETSC_DETERMINE,rank? pi2:pi1,rank? pj2:pj1,rank? pa2:pa1,&P);
 66:   MatPtAP(A,P,MAT_INITIAL_MATRIX,1.1,&PtAP);
 67:   MatView(A,NULL);
 68:   MatView(P,NULL);
 69:   MatView(PtAP,NULL);
 70:   MatPtAP(A,P,MAT_REUSE_MATRIX,1.1,&PtAP);
 71:   MatView(A,NULL);
 72:   MatView(P,NULL);
 73:   MatView(PtAP,NULL);
 74:   MatDestroy(&A);
 75:   MatDestroy(&P);
 76:   MatDestroy(&PtAP);
 77:   PetscFinalize();
 78:   return ierr;
 79: }

 81: /*TEST
 82:    test:
 83:      nsize: 2
 84:      args:   -matptap_via allatonce
 85:      output_file: output/ex90_1.out

 87:    test:
 88:      nsize: 2
 89:      suffix: merged
 90:      args:   -matptap_via allatonce_merged
 91:      output_file: output/ex90_1.out

 93: TEST*/