petsc-3.14.6 2021-03-30

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 on Vec

Input Parameter

	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

- 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

Level

advanced

Location

src/vec/vec/utils/vinv.c
Index of all Vec routines
Table of Contents for all manual pages
Index of all manual pages