VecStrideSubSetGather#

Gathers a subset of components from a multi-component vector into another vector.

Synopsis#

#include "petscvec.h" 
PetscErrorCode VecStrideSubSetGather(Vec v, PetscInt nidx, const PetscInt idxv[], const PetscInt idxs[], Vec s, InsertMode addv)

Collective

Input Parameters#

  • v - the vector

  • nidx - the number of indices

  • idxv - the indices of the components 0 <= idxv[0] …idxv[nidx-1] < bs(v), they need not be sorted

  • idxs - the indices of the components 0 <= idxs[0] …idxs[nidx-1] < bs(s), they need not be sorted, may be null if nidx == bs(s) or is PETSC_DETERMINE

  • addv - one of ADD_VALUES, INSERT_VALUES, MAX_VALUES

Output Parameter#

  • s - the location where the subvector is stored

Notes#

One must call VecSetBlockSize() on both vectors before this routine to set the stride information, or use a vector created from a multicomponent DMDA.

The parallel layout of the vector and the subvector must be the same;

Not optimized; could be easily

See Also#

Vec, VecStrideNorm(), VecStrideScatter(), VecStrideGather(), VecStrideSubSetScatter(), VecStrideMin(), VecStrideMax(), VecStrideGatherAll(), VecStrideScatterAll()

Level#

advanced

Location#

src/vec/vec/utils/vinv.c

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Index of all Vec routines
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Index of all manual pages