dust3d/thirdparty/cgal/CGAL-5.1/include/CGAL/Eigen_sparse_matrix.h

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// Copyright (c) 2012 INRIA Bordeaux Sud-Ouest (France), All rights reserved.
//
// This file is part of CGAL (www.cgal.org)
//
// $URL: https://github.com/CGAL/cgal/blob/v5.1/Solver_interface/include/CGAL/Eigen_sparse_matrix.h $
// $Id: Eigen_sparse_matrix.h 127bf54 2019-12-09T16:39:19+01:00 Mael Rouxel-Labbé
// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
//
// Author(s) : Gael Guennebaud
#ifndef CGAL_SOLVER_INTERFACE_EIGEN_SPARSE_MATRIX_H
#define CGAL_SOLVER_INTERFACE_EIGEN_SPARSE_MATRIX_H
#include <CGAL/basic.h> // include basic.h before testing #defines
#include <Eigen/Sparse>
namespace CGAL {
/*!
\ingroup PkgSolverInterfaceRef
The class `Eigen_sparse_matrix` is a wrapper around `Eigen` matrix type
<a href="http://eigen.tuxfamily.org/dox/classEigen_1_1SparseMatrix.html">`Eigen::SparseMatrix`</a>
that represents general matrices, be they symmetric or not.
\cgalModels `SparseLinearAlgebraTraits_d::Matrix`
\tparam T Number type.
\sa `CGAL::Eigen_vector<T>`
\sa `CGAL::Eigen_matrix<T>`
\sa `CGAL::Eigen_sparse_symmetric_matrix<T>`
*/
template<class T>
struct Eigen_sparse_matrix
{
// Public types
public:
/// \name Types
/// @{
/// The internal matrix type from \ref thirdpartyEigen "Eigen".
typedef Eigen::SparseMatrix<T> EigenType;
typedef T NT;
/// @}
Eigen_sparse_matrix(const EigenType& et)
: m_is_already_built(true), m_matrix(et), m_is_symmetric(false)
{}
// Public operations
public:
Eigen_sparse_matrix() : m_is_already_built(false) { }
/// Create a square matrix initialized with zeros.
Eigen_sparse_matrix(std::size_t dim, ///< Matrix dimension.
bool is_symmetric = false) ///< Symmetric/hermitian?
:
m_is_already_built(false),
m_matrix(static_cast<int>(dim), static_cast<int>(dim))
{
CGAL_precondition(dim > 0);
m_is_symmetric = is_symmetric;
m_triplets.reserve(dim); // reserve memory for a regular 3D grid
}
/// Create a square matrix initialized with zeros.
Eigen_sparse_matrix(int dim, ///< Matrix dimension.
bool is_symmetric = false) ///< Symmetric/hermitian?
: m_is_already_built(false),
m_matrix(dim, dim)
{
CGAL_precondition(dim > 0);
m_is_symmetric = is_symmetric;
// reserve memory for a regular 3D grid
m_triplets.reserve(dim);
}
/// Create a rectangular matrix initialized with zeros.
///
/// \pre rows == columns if `is_symmetric` is true.
Eigen_sparse_matrix(std::size_t rows, ///< Number of rows.
std::size_t columns, ///< Number of columns.
bool is_symmetric = false) ///< Symmetric/hermitian?
: m_is_already_built(false),
m_matrix(static_cast<int>(rows), static_cast<int>(columns))
{
CGAL_precondition(rows > 0);
CGAL_precondition(columns > 0);
if(m_is_symmetric)
{
CGAL_precondition(rows == columns);
}
m_is_symmetric = is_symmetric;
// reserve memory for a regular 3D grid
m_triplets.reserve(rows);
}
void swap(Eigen_sparse_matrix& other)
{
std::swap(m_is_already_built, other.m_is_already_built);
std::swap(m_is_symmetric, other.m_is_symmetric);
m_matrix.swap(other.m_matrix);
m_triplets.swap(other.m_triplets);
}
/// Delete this object and the wrapped matrix.
~Eigen_sparse_matrix() { }
/// Create a rectangular matrix initialized with zeros.
///
/// \pre rows == columns if `is_symmetric` is true.
Eigen_sparse_matrix(int rows, ///< Number of rows.
int columns, ///< Number of columns.
bool is_symmetric = false) ///< Symmetric/hermitian?
: m_is_already_built(false),
m_matrix(rows,columns)
{
CGAL_precondition(rows > 0);
CGAL_precondition(columns > 0);
if(is_symmetric)
{
CGAL_precondition(rows == columns);
}
m_is_symmetric = is_symmetric;
// reserve memory for a regular 3D grid
m_triplets.reserve(rows);
}
/// Return the matrix number of rows
int row_dimension() const { return static_cast<int>(m_matrix.rows()); }
/// Return the matrix number of columns
int column_dimension() const { return static_cast<int>(m_matrix.cols()); }
/// Write access to a matrix coefficient: a_ij <- val.
///
/// Users can optimize calls to this function by setting 'new_coef' to `true`
/// if the coefficient does not already exist in the matrix.
///
/// \warning For symmetric matrices, `Eigen_sparse_matrix` only stores the lower triangle
/// and `set_coef()` does nothing if (i, j) belongs to the upper triangle.
///
/// \pre 0 <= i < row_dimension().
/// \pre 0 <= j < column_dimension().
void set_coef(std::size_t i_, std::size_t j_, T val, bool new_coef = false)
{
int i = static_cast<int>(i_);
int j = static_cast<int>(j_);
CGAL_precondition(i < row_dimension());
CGAL_precondition(j < column_dimension());
if (m_is_symmetric && (j > i))
return;
if(m_is_already_built)
{
m_matrix.coeffRef(i,j) = val;
}
else
{
if(new_coef == false)
{
assemble_matrix();
m_matrix.coeffRef(i,j) = val;
}
else
{
m_triplets.push_back(Triplet(i,j,val));
}
}
}
/// Write access to a matrix coefficient: a_ij <- a_ij + val.
///
/// \warning For symmetric matrices, Eigen_sparse_matrix only stores the lower triangle
/// `add_coef()` does nothing if (i, j) belongs to the upper triangle.
///
/// \pre 0 <= i < row_dimension().
/// \pre 0 <= j < column_dimension().
void add_coef(std::size_t i_, std::size_t j_, T val)
{
int i = static_cast<int>(i_);
int j = static_cast<int>(j_);
if(m_is_symmetric && (j > i))
return;
if(m_is_already_built){
CGAL_precondition(i < row_dimension());
CGAL_precondition(j < column_dimension());
m_matrix.coeffRef(i,j) += val;
}else{
m_triplets.push_back(Triplet(i,j,val));
}
}
/// Read access to a matrix coefficient.
///
/// \warning Complexity:
/// - O(log(n)) if the matrix is already built.
/// - O(n) if the matrix is not built.
/// `n` being the number of entries in the matrix.
///
/// \pre 0 <= i < row_dimension().
/// \pre 0 <= j < column_dimension().
NT get_coef (std::size_t i_, std::size_t j_) const
{
int i = static_cast<int>(i_);
int j = static_cast<int>(j_);
CGAL_precondition(i < row_dimension());
CGAL_precondition(j < column_dimension());
if(m_is_symmetric && j > i)
std::swap(i, j);
if (m_is_already_built)
return m_matrix.coeffRef(i,j);
else
{
NT val = 0;
for(std::size_t t=0; t<m_triplets.size(); ++t)
{
if(m_triplets[t].col() == j &&
m_triplets[t].row() == i)
val += m_triplets[t].value();
}
return val;
}
}
/// \cond SKIP_IN_MANUAL
void assemble_matrix() const
{
m_matrix.setFromTriplets(m_triplets.begin(), m_triplets.end());
m_is_already_built = true;
m_triplets.clear(); // the matrix is built and will not be rebuilt
}
/// \endcond
/// Return the internal matrix, with type `EigenType`.
const EigenType& eigen_object() const
{
if(!m_is_already_built)
assemble_matrix();
// turns the matrix into compressed mode:
// -> release some memory
// -> required for some external solvers
m_matrix.makeCompressed();
return m_matrix;
}
/// Return the internal matrix, with type `EigenType`.
EigenType& eigen_object()
{
if(!m_is_already_built)
assemble_matrix();
// turns the matrix into compressed mode:
// -> release some memory
// -> required for some external solvers
m_matrix.makeCompressed();
return m_matrix;
}
public:
/// \cond SKIP_IN_MANUAL
friend Eigen_sparse_matrix
operator*(const T& c, const Eigen_sparse_matrix& M)
{
return Eigen_sparse_matrix(c* M.eigen_object());
}
friend Eigen_sparse_matrix
operator+(const Eigen_sparse_matrix& M0, const Eigen_sparse_matrix& M1)
{
return Eigen_sparse_matrix(M0.eigen_object()+ M1.eigen_object());
}
/// \endcond
// Fields
private:
mutable bool m_is_already_built;
typedef Eigen::Triplet<T,int> Triplet;
mutable std::vector<Triplet> m_triplets;
mutable EigenType m_matrix;
// Symmetric/hermitian?
bool m_is_symmetric;
}; // Eigen_sparse_matrix
/*!
\ingroup PkgSolverInterfaceRef
The class `Eigen_sparse_symmetric_matrix` is a wrapper around `Eigen` matrix type
<a href="http://eigen.tuxfamily.org/dox/classEigen_1_1SparseMatrix.html">`Eigen::SparseMatrix` </a>
Since the matrix is symmetric, only the lower triangle part is stored.
\cgalModels `SparseLinearAlgebraTraits_d::Matrix`
\tparam T Number type.
\sa `CGAL::Eigen_vector<T>`
\sa `CGAL::Eigen_sparse_matrix<T>`
*/
template<class T>
struct Eigen_sparse_symmetric_matrix
: public Eigen_sparse_matrix<T>
{
/// Create a square *symmetric* matrix initialized with zeros.
Eigen_sparse_symmetric_matrix(int dim) ///< Matrix dimension.
: Eigen_sparse_matrix<T>(dim, true /* symmetric */)
{ }
/// Create a square *symmetric* matrix initialized with zeros.
///
/// \pre rows == columns.
Eigen_sparse_symmetric_matrix(int rows, ///< Number of rows.
int columns) ///< Number of columns.
: Eigen_sparse_matrix<T>(rows, columns, true /* symmetric */)
{ }
};
} //namespace CGAL
#endif // CGAL_SOLVER_INTERFACE_EIGEN_SPARSE_MATRIX_H