mirror of
https://gitlab.com/libeigen/eigen.git
synced 2024-12-21 07:19:46 +08:00
71 lines
2.4 KiB
Plaintext
71 lines
2.4 KiB
Plaintext
// This file is part of Eigen, a lightweight C++ template library
|
|
// for linear algebra.
|
|
//
|
|
// This Source Code Form is subject to the terms of the Mozilla
|
|
// Public License v. 2.0. If a copy of the MPL was not distributed
|
|
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
|
|
|
|
#ifndef EIGEN_ORDERINGMETHODS_MODULE_H
|
|
#define EIGEN_ORDERINGMETHODS_MODULE_H
|
|
|
|
#include "SparseCore"
|
|
|
|
#include "src/Core/util/DisableStupidWarnings.h"
|
|
|
|
/**
|
|
* \defgroup OrderingMethods_Module OrderingMethods module
|
|
*
|
|
* This module is currently for internal use only
|
|
*
|
|
* It defines various built-in and external ordering methods for sparse matrices.
|
|
* They are typically used to reduce the number of elements during
|
|
* the sparse matrix decomposition (LLT, LU, QR).
|
|
* Precisely, in a preprocessing step, a permutation matrix P is computed using
|
|
* those ordering methods and applied to the columns of the matrix.
|
|
* Using for instance the sparse Cholesky decomposition, it is expected that
|
|
* the nonzeros elements in LLT(A*P) will be much smaller than that in LLT(A).
|
|
*
|
|
*
|
|
* Usage :
|
|
* \code
|
|
* #include <Eigen/OrderingMethods>
|
|
* \endcode
|
|
*
|
|
* A simple usage is as a template parameter in the sparse decomposition classes :
|
|
*
|
|
* \code
|
|
* SparseLU<MatrixType, COLAMDOrdering<int> > solver;
|
|
* \endcode
|
|
*
|
|
* \code
|
|
* SparseQR<MatrixType, COLAMDOrdering<int> > solver;
|
|
* \endcode
|
|
*
|
|
* It is possible as well to call directly a particular ordering method for your own purpose,
|
|
* \code
|
|
* AMDOrdering<int> ordering;
|
|
* PermutationMatrix<Dynamic, Dynamic, int> perm;
|
|
* SparseMatrix<double> A;
|
|
* //Fill the matrix ...
|
|
*
|
|
* ordering(A, perm); // Call AMD
|
|
* \endcode
|
|
*
|
|
* \note Some of these methods (like AMD or METIS), need the sparsity pattern
|
|
* of the input matrix to be symmetric. When the matrix is structurally unsymmetric,
|
|
* Eigen computes internally the pattern of \f$A^T*A\f$ before calling the method.
|
|
* If your matrix is already symmetric (at leat in structure), you can avoid that
|
|
* by calling the method with a SelfAdjointView type.
|
|
*
|
|
* \code
|
|
* // Call the ordering on the pattern of the lower triangular matrix A
|
|
* ordering(A.selfadjointView<Lower>(), perm);
|
|
* \endcode
|
|
*/
|
|
|
|
#include "src/OrderingMethods/Amd.h"
|
|
#include "src/OrderingMethods/Ordering.h"
|
|
#include "src/Core/util/ReenableStupidWarnings.h"
|
|
|
|
#endif // EIGEN_ORDERINGMETHODS_MODULE_H
|