petsc-3.14.6 2021-03-30
ISIntersect
Computes the intersection of two index sets, by sorting and comparing.
Synopsis
#include "petscis.h"
PetscErrorCode ISIntersect(IS is1,IS is2,IS *isout)
Collective on IS
Input Parameter
| is1 | - first index set
|
| is2 | - second index set
|
Output Parameters
| isout | - the sorted intersection of is1 and is2
|
Notes
Negative values are removed from the lists. This requires O(min(is1,is2))
memory and O(max(is1,is2)log(max(is1,is2))) work
The IS's do not need to be sorted.
See Also
ISDestroy(), ISView(), ISDifference(), ISSum(), ISExpand()
Level
intermediate
Location
src/vec/is/is/utils/isdiff.c
Index of all IS routines
Table of Contents for all manual pages
Index of all manual pages