Actual source code: ex38.c

petsc-3.12.2 2019-11-22
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  1: static const char help[] = "Test VecGetSubVector()\n\n";

  3:  #include <petscvec.h>

  5: int main(int argc, char *argv[])
  6: {
  7:   MPI_Comm       comm;
  8:   Vec            X,Y,Z,W;
  9:   PetscMPIInt    rank,size;
 10:   PetscInt       i,rstart,rend,idxs[3];
 11:   PetscScalar    *x;
 12:   PetscViewer    viewer;
 13:   IS             is0,is1,is2;

 16:   PetscInitialize(&argc,&argv,0,help);if (ierr) return ierr;
 17:   comm   = PETSC_COMM_WORLD;
 18:   viewer = PETSC_VIEWER_STDOUT_WORLD;
 19:   MPI_Comm_size(comm,&size);
 20:   MPI_Comm_rank(comm,&rank);

 22:   VecCreate(comm,&X);
 23:   VecSetSizes(X,10,PETSC_DETERMINE);
 24:   VecSetFromOptions(X);
 25:   VecGetOwnershipRange(X,&rstart,&rend);

 27:   VecGetArray(X,&x);
 28:   for (i=0; i<rend-rstart; i++) x[i] = rstart+i;
 29:   VecRestoreArray(X,&x);

 31:   idxs[0] = (size - rank - 1)*10 + 5;
 32:   idxs[1] = (size - rank - 1)*10 + 2;
 33:   idxs[2] = (size - rank - 1)*10 + 3;

 35:   ISCreateStride(comm,(rend-rstart)/3+3*(rank>size/2),rstart,1,&is0);
 36:   ISComplement(is0,rstart,rend,&is1);
 37:   ISCreateGeneral(comm,3,idxs,PETSC_USE_POINTER,&is2);

 39:   ISView(is0,viewer);
 40:   ISView(is1,viewer);
 41:   ISView(is2,viewer);

 43:   VecGetSubVector(X,is0,&Y);
 44:   VecGetSubVector(X,is1,&Z);
 45:   VecGetSubVector(X,is2,&W);
 46:   VecView(Y,viewer);
 47:   VecView(Z,viewer);
 48:   VecView(W,viewer);
 49:   VecRestoreSubVector(X,is0,&Y);
 50:   VecRestoreSubVector(X,is1,&Z);
 51:   VecRestoreSubVector(X,is2,&W);

 53:   ISDestroy(&is0);
 54:   ISDestroy(&is1);
 55:   ISDestroy(&is2);
 56:   VecDestroy(&X);
 57:   PetscFinalize();
 58:   return ierr;
 59: }


 62: /*TEST

 64:    testset:
 65:       nsize: 3
 66:       output_file: output/ex38_1.out
 67:       filter: grep -v "  type:"
 68:       test:
 69:         suffix: standard
 70:         args: -vec_type standard
 71:       test:
 72:         requires: cuda
 73:         suffix: cuda
 74:         args: -vec_type cuda
 75:       test:
 76:         requires: viennacl
 77:         suffix:  viennacl
 78:         args: -vec_type viennacl

 80: TEST*/