petsc-3.8.4 2018-03-24

VecWhichEqual

Creates an index set containing the indices where the vectors Vec1 and Vec2 have identical elements.

#include "petscvec.h"  
PetscErrorCode VecWhichEqual(Vec Vec1, Vec Vec2, IS * S)

Collective on Vec

Vec1, Vec2 -the two vectors to compare

S -The index set containing the indices i where vec1[i] == vec2[i]

Notes: the two vectors must have the same parallel layout