petsc-3.10.5 2019-03-28
VecStrideGather
Gathers a single component from a multi-component vector into another vector.
Synopsis
#include "petscvec.h"
PetscErrorCode VecStrideGather(Vec v,PetscInt start,Vec s,InsertMode addv)
Collective on Vec
Input Parameter
Output Parameter
s -the location where the subvector is stored
Notes
One must call VecSetBlockSize() before this routine to set the stride
information, or use a vector created from a multicomponent DMDA.
If x is the array representing the vector x then this gathers
the array (x[start],x[start+stride],x[start+2*stride], ....)
The parallel layout of the vector and the subvector must be the same;
i.e., nlocal of v = stride*(nlocal of s)
Not optimized; could be easily
See Also
VecStrideNorm(), VecStrideScatter(), VecStrideMin(), VecStrideMax(), VecStrideGatherAll(),
VecStrideScatterAll()
Level
advanced
Location
src/vec/vec/utils/vinv.c
Examples
src/vec/vec/examples/tutorials/ex12.c.html
src/vec/vec/examples/tutorials/ex16.c.html
Index of all Vec routines
Table of Contents for all manual pages
Index of all manual pages