Precond¶
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class
Precond(*args)¶ GetFEM Precond object
The preconditioners may store REAL or COMPLEX values. They accept getfem sparse matrices and Matlab sparse matrices.
General constructor for Precond objects
PC = Precond('identity')Create a REAL identity precondioner.PC = Precond('cidentity')Create a COMPLEX identity precondioner.PC = Precond('diagonal', vec D)Create a diagonal precondioner.PC = Precond('ildlt', SpMat m)Create an ILDLT (Cholesky) preconditioner for the (symmetric) sparse matrix m. This preconditioner has the same sparsity pattern than m (no fill-in).PC = Precond('ilu', SpMat m)Create an ILU (Incomplete LU) preconditioner for the sparse matrix m. This preconditioner has the same sparsity pattern than m (no fill-in).PC = Precond('ildltt', SpMat m[, int fillin[, scalar threshold]])Create an ILDLTT (Cholesky with filling) preconditioner for the (symmetric) sparse matrix m. The preconditioner may add at most fillin additional non-zero entries on each line. The default value for fillin is 10, and the default threshold is1e-7.PC = Precond('ilut', SpMat m[, int fillin[, scalar threshold]])Create an ILUT (Incomplete LU with filling) preconditioner for the sparse matrix m. The preconditioner may add at most fillin additional non-zero entries on each line. The default value for fillin is 10, and the default threshold is 1e-7.PC = Precond('superlu', SpMat m)Uses SuperLU to build an exact factorization of the sparse matrix m. This preconditioner is only available if the getfem-interface was built with SuperLU support. Note that LU factorization is likely to eat all your memory for 3D problems.PC = Precond('spmat', SpMat m)Preconditioner given explicitely by a sparse matrix.
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char()¶ Output a (unique) string representation of the Precond.
This can be used to perform comparisons between two different Precond objects. This function is to be completed.
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display()¶ displays a short summary for a Precond object.
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is_complex()¶ Return 1 if the preconditioner stores complex values.
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mult(V)¶ Apply the preconditioner to the supplied vector.
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size()¶ Return the dimensions of the preconditioner.
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tmult(V)¶ Apply the transposed preconditioner to the supplied vector.
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type()¶ Return a string describing the type of the preconditioner (‘ilu’, ‘ildlt’,..).