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 Parameters#

  • 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


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Index of all IS routines
Table of Contents for all manual pages
Index of all manual pages