Localized Schur
The Localized Schur node () is an attribute to a Schur Solver and to a Krylov Preconditioner added under a Schur Solver node. It is an alternative to the default Sparse Localized Schur node. The Localized Schur method solves a filled, dense equation system, whereas the Sparse Localized Schur method filters out small matrix elements and can therefore use all solvers.
Use the Termination technique list to select how to terminate the solver. Select:
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Fixed number of iterations (the default) to perform a fixed number of iterations each time the Schur Solver is used.
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Use tolerance to terminate the Schur Solver when a tolerance is fulfilled.
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Iterations or tolerance to terminate when the estimated tolerance is smaller than a specified tolerance or after a specified number of iterations, whichever comes first.
Further options that apply to the selection (as indicated at each bullet) made in the Termination technique list are:
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Number of iterations (available when Termination technique is set to Fixed number of iterations or Iterations or tolerance). Use this field to specify the fixed number of iterations to perform (default: 2).
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Relative tolerance (available when Termination technique is set to Use tolerance or Iterations or tolerance). Use this field to specify the termination tolerance (default: 0.1).
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Maximum number of iterations (only available when Termination technique is set to Use tolerance). Use this field to enter a maximum number of iterations that the solver is allowed to take (default: 10). When this number of iterations has been performed without reaching the tolerance specified in the Relative tolerance field, the solver automatically stops with an error message.