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- // This file is part of Eigen, a lightweight C++ template library
- // for linear algebra.
- //
- // Copyright (C) 2014 Gael Guennebaud <gael.guennebaud@inria.fr>
- //
- // 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_SPARSESOLVERBASE_H
- #define EIGEN_SPARSESOLVERBASE_H
- namespace Eigen {
- namespace internal {
- /** \internal
- * Helper functions to solve with a sparse right-hand-side and result.
- * The rhs is decomposed into small vertical panels which are solved through dense temporaries.
- */
- template<typename Decomposition, typename Rhs, typename Dest>
- typename enable_if<Rhs::ColsAtCompileTime!=1 && Dest::ColsAtCompileTime!=1>::type
- solve_sparse_through_dense_panels(const Decomposition &dec, const Rhs& rhs, Dest &dest)
- {
- EIGEN_STATIC_ASSERT((Dest::Flags&RowMajorBit)==0,THIS_METHOD_IS_ONLY_FOR_COLUMN_MAJOR_MATRICES);
- typedef typename Dest::Scalar DestScalar;
- // we process the sparse rhs per block of NbColsAtOnce columns temporarily stored into a dense matrix.
- static const Index NbColsAtOnce = 4;
- Index rhsCols = rhs.cols();
- Index size = rhs.rows();
- // the temporary matrices do not need more columns than NbColsAtOnce:
- Index tmpCols = (std::min)(rhsCols, NbColsAtOnce);
- Eigen::Matrix<DestScalar,Dynamic,Dynamic> tmp(size,tmpCols);
- Eigen::Matrix<DestScalar,Dynamic,Dynamic> tmpX(size,tmpCols);
- for(Index k=0; k<rhsCols; k+=NbColsAtOnce)
- {
- Index actualCols = std::min<Index>(rhsCols-k, NbColsAtOnce);
- tmp.leftCols(actualCols) = rhs.middleCols(k,actualCols);
- tmpX.leftCols(actualCols) = dec.solve(tmp.leftCols(actualCols));
- dest.middleCols(k,actualCols) = tmpX.leftCols(actualCols).sparseView();
- }
- }
- // Overload for vector as rhs
- template<typename Decomposition, typename Rhs, typename Dest>
- typename enable_if<Rhs::ColsAtCompileTime==1 || Dest::ColsAtCompileTime==1>::type
- solve_sparse_through_dense_panels(const Decomposition &dec, const Rhs& rhs, Dest &dest)
- {
- typedef typename Dest::Scalar DestScalar;
- Index size = rhs.rows();
- Eigen::Matrix<DestScalar,Dynamic,1> rhs_dense(rhs);
- Eigen::Matrix<DestScalar,Dynamic,1> dest_dense(size);
- dest_dense = dec.solve(rhs_dense);
- dest = dest_dense.sparseView();
- }
- } // end namespace internal
- /** \class SparseSolverBase
- * \ingroup SparseCore_Module
- * \brief A base class for sparse solvers
- *
- * \tparam Derived the actual type of the solver.
- *
- */
- template<typename Derived>
- class SparseSolverBase : internal::noncopyable
- {
- public:
- /** Default constructor */
- SparseSolverBase()
- : m_isInitialized(false)
- {}
- ~SparseSolverBase()
- {}
- Derived& derived() { return *static_cast<Derived*>(this); }
- const Derived& derived() const { return *static_cast<const Derived*>(this); }
-
- /** \returns an expression of the solution x of \f$ A x = b \f$ using the current decomposition of A.
- *
- * \sa compute()
- */
- template<typename Rhs>
- inline const Solve<Derived, Rhs>
- solve(const MatrixBase<Rhs>& b) const
- {
- eigen_assert(m_isInitialized && "Solver is not initialized.");
- eigen_assert(derived().rows()==b.rows() && "solve(): invalid number of rows of the right hand side matrix b");
- return Solve<Derived, Rhs>(derived(), b.derived());
- }
-
- /** \returns an expression of the solution x of \f$ A x = b \f$ using the current decomposition of A.
- *
- * \sa compute()
- */
- template<typename Rhs>
- inline const Solve<Derived, Rhs>
- solve(const SparseMatrixBase<Rhs>& b) const
- {
- eigen_assert(m_isInitialized && "Solver is not initialized.");
- eigen_assert(derived().rows()==b.rows() && "solve(): invalid number of rows of the right hand side matrix b");
- return Solve<Derived, Rhs>(derived(), b.derived());
- }
-
- #ifndef EIGEN_PARSED_BY_DOXYGEN
- /** \internal default implementation of solving with a sparse rhs */
- template<typename Rhs,typename Dest>
- void _solve_impl(const SparseMatrixBase<Rhs> &b, SparseMatrixBase<Dest> &dest) const
- {
- internal::solve_sparse_through_dense_panels(derived(), b.derived(), dest.derived());
- }
- #endif // EIGEN_PARSED_BY_DOXYGEN
- protected:
-
- mutable bool m_isInitialized;
- };
- } // end namespace Eigen
- #endif // EIGEN_SPARSESOLVERBASE_H
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