PCExoticSetType#

Sets the type of coarse grid interpolation to use

Synopsis#

#include "petscdmda.h" 
#include "petscksp.h" 
PetscErrorCode PCExoticSetType(PC pc, PCExoticType type)

Logically Collective

Input Parameters#

pc - the preconditioner context
type - either PC_EXOTIC_FACE or PC_EXOTIC_WIREBASKET (defaults to face)

Options Database Keys#

-pc_exotic_type <face,wirebasket> - use a coarse grid point for each face, or edge and vertex

Notes#

The face based interpolation has 1 degree of freedom per face and ignores the edge and vertex values completely in the coarse problem. For any seven point stencil the interpolation of a constant on all faces into the interior is that constant.

The wirebasket interpolation has 1 degree of freedom per vertex, per edge and per face. A constant on the subdomain boundary is interpolated as that constant in the interior of the domain.

The coarse grid matrix is obtained via the Galerkin computation \(A_c = R A R^T\), hence if \(A\) is nonsingular \(A_c\) is also nonsingular.

Both interpolations are suitable for only scalar problems.

Level#

intermediate

Location#

src/ksp/pc/impls/wb/wb.c

Implementations#

PCExoticSetType_Exotic() in src/ksp/pc/impls/wb/wb.c

Index of all PC routines
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Index of all manual pages