Public Member Functions | |
| AdditionalData (const bool elliptic=true, const bool higher_order_elements=false, const unsigned int n_cycles=1, const bool w_cyle=false, const double aggregation_threshold=1e-4, const std::vector< std::vector< bool > > &constant_modes=std::vector< std::vector< bool > >(1), const unsigned int smoother_sweeps=2, const unsigned int smoother_overlap=0, const bool output_details=false) | |
Public Attributes | |
| bool | elliptic |
| bool | higher_order_elements |
| unsigned int | n_cycles |
| bool | w_cycle |
| double | aggregation_threshold |
| std::vector< std::vector< bool > > | constant_modes |
| unsigned int | smoother_sweeps |
| unsigned int | smoother_overlap |
| bool | output_details |
Definition at line 1253 of file trilinos_precondition.h.
| TrilinosWrappers::PreconditionAMG::AdditionalData::AdditionalData | ( | const bool | elliptic = true, |
| const bool | higher_order_elements = false, |
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| const unsigned int | n_cycles = 1, |
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| const bool | w_cyle = false, |
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| const double | aggregation_threshold = 1e-4, |
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| const std::vector< std::vector< bool > > & | constant_modes = std::vector< std::vector< bool > >(1), |
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| const unsigned int | smoother_sweeps = 2, |
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| const unsigned int | smoother_overlap = 0, |
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| const bool | output_details = false |
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| ) |
Constructor. By default, we pretend to work on elliptic problems with linear finite elements on a scalar equation.
Determines whether the AMG preconditioner should be optimized for elliptic problems (ML option smoothed aggregation SA, using a Chebyshev smoother) or for non-elliptic problems (ML option non-symmetric smoothed aggregation NSSA, smoother is SSOR with underrelaxation).
Definition at line 1282 of file trilinos_precondition.h.
Determines whether the matrix that the preconditioner is built upon is generated from linear or higher-order elements.
Definition at line 1290 of file trilinos_precondition.h.
Defines how many multigrid cycles should be performed by the preconditioner.
Definition at line 1297 of file trilinos_precondition.h.
Defines whether a w-cycle should be used instead of the standard setting of a v-cycle.
Definition at line 1304 of file trilinos_precondition.h.
This threshold tells the AMG setup how the coarsening should be performed. In the AMG used by ML, all points that strongly couple with the tentative coarse-level point form one aggregate. The term strong coupling is controlled by the variable aggregation_threshold, meaning that all elements that are not smaller than aggregation_threshold times the diagonal element do couple strongly.
Definition at line 1322 of file trilinos_precondition.h.
| std::vector<std::vector<bool> > TrilinosWrappers::PreconditionAMG::AdditionalData::constant_modes |
Specifies the constant modes (near null space) of the matrix. This parameter tells AMG whether we work on a scalar equation (where the near null space only consists of ones) or on a vector-valued equation.
Definition at line 1333 of file trilinos_precondition.h.
Determines how many sweeps of the smoother should be performed. When the flag elliptic is set to true, i.e., for elliptic or almost elliptic problems, the polynomial degree of the Chebyshev smoother is set to smoother_sweeps. The term sweeps refers to the number of matrix-vector products performed in the Chebyshev case. In the non-elliptic case, smoother_sweeps sets the number of SSOR relaxation sweeps for post-smoothing to be performed.
Definition at line 1353 of file trilinos_precondition.h.
Determines the overlap in the SSOR/Chebyshev error smoother when run in parallel.
Definition at line 1360 of file trilinos_precondition.h.
If this flag is set to true, then internal information from the ML preconditioner is printed to screen. This can be useful when debugging the preconditioner.
Definition at line 1370 of file trilinos_precondition.h.
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