petsc-3.8.4 2018-03-24

PCASMSetLocalSubdomains

Sets the local subdomains (for this processor only) for the additive Schwarz preconditioner.

Synopsis

#include "petscpc.h" 
PetscErrorCode  PCASMSetLocalSubdomains(PC pc,PetscInt n,IS is[],IS is_local[])

Collective on PC

Input Parameters

	pc	- the preconditioner context
	n	- the number of subdomains for this processor (default value = 1)
	is	- the index set that defines the subdomains for this processor (or NULL for PETSc to determine subdomains)
	is_local	- the index sets that define the local part of the subdomains for this processor, not used unless PCASMType is PC_ASM_RESTRICT (or NULL to not provide these)

Notes

The IS numbering is in the parallel, global numbering of the vector for both is and is_local

By default the ASM preconditioner uses 1 block per processor.

Use PCASMSetTotalSubdomains() to set the subdomains for all processors.

If is_local is provided and PCASMType is PC_ASM_RESTRICT then the solution only over the is_local region is interpolated back to form the global solution (this is the standard restricted additive Schwarz method)

If the is_local is provided and PCASMType is PC_ASM_INTERPOLATE or PC_ASM_NONE then an error is generated since there is no code to handle that case.

Keywords

PC, ASM, set, local, subdomains, additive Schwarz

Examples