74 lines
2.4 KiB
Plaintext
74 lines
2.4 KiB
Plaintext
// This file is part of Eigen, a lightweight C++ template library
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// for linear algebra.
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//
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// This Source Code Form is subject to the terms of the Mozilla
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// Public License v. 2.0. If a copy of the MPL was not distributed
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// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
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#ifndef EIGEN_ORDERINGMETHODS_MODULE_H
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#define EIGEN_ORDERINGMETHODS_MODULE_H
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#include "SparseCore"
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#include "src/Core/util/DisableStupidWarnings.h"
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/**
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* \defgroup OrderingMethods_Module OrderingMethods module
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*
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* This module is currently for internal use only
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*
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* It defines various built-in and external ordering methods for sparse matrices.
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* They are typically used to reduce the number of elements during
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* the sparse matrix decomposition (LLT, LU, QR).
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* Precisely, in a preprocessing step, a permutation matrix P is computed using
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* those ordering methods and applied to the columns of the matrix.
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* Using for instance the sparse Cholesky decomposition, it is expected that
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* the nonzeros elements in LLT(A*P) will be much smaller than that in LLT(A).
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*
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*
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* Usage :
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* \code
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* #include <Eigen/OrderingMethods>
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* \endcode
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*
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* A simple usage is as a template parameter in the sparse decomposition classes :
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*
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* \code
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* SparseLU<MatrixType, COLAMDOrdering<int> > solver;
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* \endcode
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*
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* \code
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* SparseQR<MatrixType, COLAMDOrdering<int> > solver;
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* \endcode
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*
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* It is possible as well to call directly a particular ordering method for your own purpose,
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* \code
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* AMDOrdering<int> ordering;
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* PermutationMatrix<Dynamic, Dynamic, int> perm;
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* SparseMatrix<double> A;
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* //Fill the matrix ...
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*
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* ordering(A, perm); // Call AMD
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* \endcode
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*
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* \note Some of these methods (like AMD or METIS), need the sparsity pattern
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* of the input matrix to be symmetric. When the matrix is structurally unsymmetric,
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* Eigen computes internally the pattern of \f$A^T*A\f$ before calling the method.
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* If your matrix is already symmetric (at least in structure), you can avoid that
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* by calling the method with a SelfAdjointView type.
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*
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* \code
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* // Call the ordering on the pattern of the lower triangular matrix A
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* ordering(A.selfadjointView<Lower>(), perm);
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* \endcode
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*/
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// IWYU pragma: begin_exports
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#include "src/OrderingMethods/Amd.h"
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#include "src/OrderingMethods/Ordering.h"
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// IWYU pragma: end_exports
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#include "src/Core/util/ReenableStupidWarnings.h"
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#endif // EIGEN_ORDERINGMETHODS_MODULE_H
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