petsc-3.11.4 2019-09-28
PCGAMGSetSquareGraph
Square the graph, ie. compute A'*A before aggregating it
Synopsis
#include "petscpc.h"
PetscErrorCode PCGAMGSetSquareGraph(PC pc, PetscInt n)
Not Collective on PC
Input Parameters
Options Database Key
-pc_gamg_square_graph <n,default = 1> -number of levels to square the graph on before aggregating it
Notes
Squaring the graph increases the rate of coarsening (aggressive coarsening) and thereby reduces the complexity of the coarse grids, and generally results in slower solver converge rates. Reducing coarse grid complexity reduced the complexity of Galerkin coarse grid construction considerably.
See Also
PCGAMGSetSymGraph(), PCGAMGSetThreshold()
Level
intermediate
Location
src/ksp/pc/impls/gamg/agg.c
Implementations
PCGAMGSetSquareGraph_AGG in src/ksp/pc/impls/gamg/agg.c
Index of all PC routines
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Index of all manual pages