ParPre Manual

Defined Preconditioners

(Use these as value in a callto PCSetValue.)

• PCAdditiveSchwarz
• PCMultiplicativeSchwarz
• PCGenBlockSSOR
• PCDomainDecomp
• PCMultiLevel

Process routines

Initialise/Finalise the library

• ParPreInitialize initialise use of the ParPre library.
• ParPreFinalize end use of the ParPre library.

Set up a preconditioner

• ParPreSetup.

Preconditioner routines

Schwarz methods

• PCSchwarzSetHaloSize for specifying the width of the overlap region between domains.
• PCSchwarzGetIndices for getting the indices of an extended subdomain.
• PCSchwarzGetLocalSLES for getting the local subdomain solver object.
• See also domain pipeline auxiliaries and local solver auxiliaries.

Domain Decomposition methods

• PCDomainDecompGetInterfacePC for getting the interface system solver.
• PCDomainDecompSetWidth for setting the width of the interface.

Generalised Block SSOR methods

• PCGenBlockSSORSetNoGlobalFactorisation for declaring a block ssor method not use a global factorisation.
• PCGenBlockSSORSetGlobalFactorisation for declaring that a block ssor method use a global factorisation.
• PCGenBlockSSORSetFillMethod for specifying the method of handling fill-in.
• See also domain pipeline auxiliaries for specifying the order in which subdomains are solved, and factored for methods that use a global factorisation.

Multilevel methods

• AMLSetFillMethod for specifying the fill method to be used in computing the Schur complement when eliminating onto the coarse points.
• AMLSetSolutionScheme set the solution scheme to be used for the two-level transfer.
• AMLSetCoarseGridIndependent declare that the coarse grid is to be taken as an independent set.
• AMLSetCoarseGridDependent declare that the coarse grid is to be taken as the complement of independent set.
• AMLSetSchurElimination declare that the coarse grid operator is to be formed by ILU-type elimination.
• AMLSetSchurVariational declare that the coarse grid operator is to be formed by multigrid-type variational elimination.
• AMLSetCutoffSize specify the minimum size of a subdomain for further levels to be generated.
• AMLSetStrongRatio set the ratio for strong connections.
• AMLSetCycleDegree set the degree of the generalised W-cycle.
• AMLSetModification specify whether or not to use a modified factorisation when deriving the coarse grid operator.
• AMLSetSmootherChoice specify the smoother used in a multilevel method.
• AMLSetISFromStrong specify that the independent set is derived from a matrix of strong connections.
• AMLSetISFromOriginal specify that the independent set is derived from the original matrix.

Auxiliary routines

Local Solver routines

• PCParallelGetLocalPC gets the subdomain solver preconditioner object.

Domain Pipeline routines

• PCParallelSubdomainPipelineSetType sets the type of the pipeline that connects the subdomains.
• PCParallelSubdomainPipelineGetType for getting the pipeline type.