SOR
The SOR node () handles settings for the SOR (successive overrelaxation) iterative method. Right-click the Iterative, Krylov Preconditioner, Presmoother, Postsmoother, or Coarse Solver attribute nodes to add an SOR node.
See The SOR Method for more detailed information about this feature.
General
Settings When Used with Any Attribute Node
Use the Solver list to specify which variant of the SOR algorithm to use. Select:
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SSOR (the default) to use the symmetric SOR algorithm, which in each iteration performs one SOR sweep followed by one SORU sweep.
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SOR to use the forward SOR algorithm.
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SORU to use the backward SOR (SORU) algorithm.
Specify a scalar Relaxation factor ω. The allowed values of this factor are between 0 and 2 (default: 1). See About the Relaxation Factor for more information.
The Blocked version check box is selected by default and it uses a blocked version of the SOR method that is optimized for parallel computations. M is then constructed from a column-permuted version of A.
Settings with and Without a Coarse Solver
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If used with a Coarse Solver, select a Termination technique. These are described for the SCGS attribute under Settings When Used With a Coarse Solver.
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If a Coarse Solver is not used, enter the Number of iterations to specify a fixed number of iterations to perform when this attribute is used as a preconditioner or smoother (default: 2).
This setting is not considered when the attribute is used as a linear system solver (with the Use preconditioner option in the Solver list of the Iterative node). The solver then iterates until it has established convergence or has reached the maximal number of iterations as specified by the corresponding Iterative node, rather than perform a fixed number of iterations.