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MatrixFreeTentativePFactory Class Reference

Factory for building the matrix-free tentative restrictor. More...

Detailed Description

Factory for building the matrix-free tentative restrictor.

Factory for creating the matrix-free tentative restrictor. Nullspace vectors are split across aggregates so that they have local support. The vectors with local support are factored via LAPACK QR. The Q becomes the tentative prolongator, and the R becomes the coarse nullspace.

Note that the MatrixFreeTentativePFactory also creates the coarse null space vectors, that is, it serves as generating factory for the Nullspace vectors on the coarse levels. To feed in the near null space vectors on the finest level one has to use the NullspaceFactory.

Input/output of MatrixFreeTentativePFactory

User parameters of MatrixFreeTentativePFactory

Parameter type default master.xml validated requested description
Aggregates Factory null * * Generating factory of the aggregates (of type "Aggregates" produced, e.g., by the UncoupledAggregationFactory)
Nullspace Factory null * * Generating factory of the fine nullspace vectors (of type "MultiVector"). In the default case the same instance of the MatrixFreeTentativePFactory is also the generating factory for the null space vectors (on the next coarser levels). Therefore, it is recommended to declare the MatrixFreeTentativePFactory to be the generating factory of the "Nullspace" variable globally using the FactoryManager object! For defining the near null space vectors on the finest level one should use the NullspaceFactory.
UnAmalgamationInfo Factory null * * Generating factory of UnAmalgamationInfo. This data (of type "AmalgamationInfo") is produced by the AmalgamationFactory class. The default option should be fine for most standard cases though.
CoarseMap Factory null * * Generating factory of the coarse map. The map generates the coarse domain map of the prolongation operator. The default choice should be fine as long as you do not wish some offset in the domain map (e.g. for block operators in multiphysics problems). The data is generated by the CoarseMapFactory.

The * in the master.xml column denotes that the parameter is defined in the master.xml file.
The * in the validated column means that the parameter is declared in the list of valid input parameters (see MatrixFreeTentativePFactory::GetValidParameters).
The * in the requested column states that the data is requested as input with all dependencies (see MatrixFreeTentativePFactory::DeclareInput).

Variables provided by MatrixFreeTentativePFactory

After MatrixFreeTentativePFactory::Build the following data is available (if requested)

Parameter generated by description
R MatrixFreeTentativePFactory Non-smoothed "tentative" prolongation operator (with piece-wise constant transfer operator basis functions)
Nullspace MatrixFreeTentativePFactory Coarse near null space vectors. Please also check the documentation of the NullspaceFactory for the special dependency tree of the "Nullspace" variable throughout all multigrid levels.

The documentation for this class was generated from the following file: