DMGetAdjacency#

Returns the flags for determining variable influence

Synopsis#

#include "petscdm.h"          
#include "petscdmlabel.h"     
#include "petscds.h"     
PetscErrorCode DMGetAdjacency(DM dm, PetscInt f, PetscBool *useCone, PetscBool *useClosure)

Not Collective

Input Parameters#

dm - The DM object
f - The field number, or PETSC_DEFAULT for the default adjacency

Output Parameters#

useCone - Flag for variable influence starting with the cone operation
useClosure - Flag for variable influence using transitive closure

Notes#

     FEM:   Two points p and q are adjacent if q \in closure(star(p)),   useCone = PETSC_FALSE, useClosure = PETSC_TRUE
     FVM:   Two points p and q are adjacent if q \in support(p+cone(p)), useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
     FVM++: Two points p and q are adjacent if q \in star(closure(p)),   useCone = PETSC_TRUE,  useClosure = PETSC_TRUE

Further explanation can be found in the User’s Manual Section on the Influence of Variables on One Another.