Actual source code: ex38.c

petsc-3.8.3 2017-12-09
Report Typos and Errors
  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;
  9:   PetscMPIInt    rank,size;
 10:   PetscInt       i,rstart,rend;
 11:   PetscScalar    *x;
 12:   PetscViewer    viewer;
 13:   IS             is0,is1;

 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:   ISCreateStride(comm,(rend-rstart)/3+3*(rank>size/2),rstart,1,&is0);
 32:   ISComplement(is0,rstart,rend,&is1);

 34:   ISView(is0,viewer);
 35:   ISView(is1,viewer);

 37:   VecGetSubVector(X,is0,&Y);
 38:   VecGetSubVector(X,is1,&Z);
 39:   VecView(Y,viewer);
 40:   VecView(Z,viewer);
 41:   VecRestoreSubVector(X,is0,&Y);
 42:   VecRestoreSubVector(X,is1,&Z);

 44:   ISDestroy(&is0);
 45:   ISDestroy(&is1);
 46:   VecDestroy(&X);
 47:   PetscFinalize();
 48:   return ierr;
 49: }