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Which preconditioner to use to ensure generic rank profile
NO_PRECONDITIONER - Do not use any preconditioner BUTTERFLY - Use a butterfly network, see @ref{Butterfly} SPARSE - Use a sparse preconditioner, c.f. (Mulders 2000) TOEPLITZ - Use a Toeplitz preconditioner, c.f. (Kaltofen and Saunders 1991) SYMMETRIZE - Use A^T A (Lanczos only) PARTIAL_DIAGONAL - Use AD, where D is a random nonsingular diagonal matrix (Lanczos only) PARTIAL_DIAGONAL_SYMMETRIZE - Use A^T D A, where D is a random nonsingular diagonal matrix (Lanczos only) FULL_DIAGONAL - Use D_1 A^T D_2 A D_1, where D_1 and D_2 are random nonsingular diagonal matrices (Lanczos only) DENSE (Dixon use) - Enumeration values:
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NO_PRECONDITIONER |
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BUTTERFLY |
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SPARSE |
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TOEPLITZ |
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SYMMETRIZE |
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PARTIAL_DIAGONAL |
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PARTIAL_DIAGONAL_SYMMETRIZE |
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FULL_DIAGONAL |
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DENSE |
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