DMCreateDomainDecomposition#

Returns lists of IS objects defining a decomposition of a problem into subproblems corresponding to restrictions to pairs of nested subdomains.

Synopsis#

#include "petscdm.h"          
#include "petscdmlabel.h"     
#include "petscds.h"     
PetscErrorCode DMCreateDomainDecomposition(DM dm, PetscInt *n, char ***namelist, IS **innerislist, IS **outerislist, DM **dmlist)

Not Collective

Input Parameter#

dm - the DM object

Output Parameters#

n - The number of subproblems in the domain decomposition (or NULL if not requested)
namelist - The name for each subdomain (or NULL if not requested)
innerislist - The global indices for each inner subdomain (or NULL, if not requested)
outerislist - The global indices for each outer subdomain (or NULL, if not requested)
dmlist - The DMs for each subdomain subproblem (or NULL, if not requested; if NULL is returned, no DMs are defined)

Notes#

Each IS contains the global indices of the dofs of the corresponding subdomains with in the dofs of the original DM. The inner subdomains conceptually define a nonoverlapping covering, while outer subdomains can overlap.

The optional list of DMs define a DM for each subproblem.

The user is responsible for freeing all requested arrays. In particular, every entry of namelist should be freed with PetscFree(), every entry of innerislist and outerislist should be destroyed with ISDestroy(), every entry of dmlist should be destroyed with DMDestroy(), and all of the arrays should be freed with PetscFree().

Developer Notes#

The dmlist is for the inner subdomains or the outer subdomains or all subdomains?

The names are inconsistent, the hooks use DMSubDomainHook which is nothing like DMCreateDomainDecomposition() while DMRefineHook is used for DMRefine().