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
Input Parameters#
v - the vector
start - starting point of the subvector (defined by a stride)
addv - one of
ADD_VALUES,INSERT_VALUES,MAX_VALUES
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#
Vec, VecStrideNorm(), VecStrideScatter(), VecStrideMin(), VecStrideMax(), VecStrideGatherAll(),
VecStrideScatterAll()
Level#
advanced
Location#
Examples#
src/vec/vec/tutorials/ex12.c
src/ts/tutorials/ex30.c
src/vec/vec/tutorials/ex12f.F90
Index of all Vec routines
Table of Contents for all manual pages
Index of all manual pages