add Eigen as a dependency

This commit is contained in:
Sven Czarnian
2021-12-16 15:59:56 +01:00
parent a08ac9b244
commit 27b422d806
479 changed files with 167893 additions and 0 deletions

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// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2011-2014 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_BASIC_PRECONDITIONERS_H
#define EIGEN_BASIC_PRECONDITIONERS_H
namespace Eigen {
/** \ingroup IterativeLinearSolvers_Module
* \brief A preconditioner based on the digonal entries
*
* This class allows to approximately solve for A.x = b problems assuming A is a diagonal matrix.
* In other words, this preconditioner neglects all off diagonal entries and, in Eigen's language, solves for:
\code
A.diagonal().asDiagonal() . x = b
\endcode
*
* \tparam _Scalar the type of the scalar.
*
* \implsparsesolverconcept
*
* This preconditioner is suitable for both selfadjoint and general problems.
* The diagonal entries are pre-inverted and stored into a dense vector.
*
* \note A variant that has yet to be implemented would attempt to preserve the norm of each column.
*
* \sa class LeastSquareDiagonalPreconditioner, class ConjugateGradient
*/
template <typename _Scalar>
class DiagonalPreconditioner
{
typedef _Scalar Scalar;
typedef Matrix<Scalar,Dynamic,1> Vector;
public:
typedef typename Vector::StorageIndex StorageIndex;
enum {
ColsAtCompileTime = Dynamic,
MaxColsAtCompileTime = Dynamic
};
DiagonalPreconditioner() : m_isInitialized(false) {}
template<typename MatType>
explicit DiagonalPreconditioner(const MatType& mat) : m_invdiag(mat.cols())
{
compute(mat);
}
Index rows() const { return m_invdiag.size(); }
Index cols() const { return m_invdiag.size(); }
template<typename MatType>
DiagonalPreconditioner& analyzePattern(const MatType& )
{
return *this;
}
template<typename MatType>
DiagonalPreconditioner& factorize(const MatType& mat)
{
m_invdiag.resize(mat.cols());
for(int j=0; j<mat.outerSize(); ++j)
{
typename MatType::InnerIterator it(mat,j);
while(it && it.index()!=j) ++it;
if(it && it.index()==j && it.value()!=Scalar(0))
m_invdiag(j) = Scalar(1)/it.value();
else
m_invdiag(j) = Scalar(1);
}
m_isInitialized = true;
return *this;
}
template<typename MatType>
DiagonalPreconditioner& compute(const MatType& mat)
{
return factorize(mat);
}
/** \internal */
template<typename Rhs, typename Dest>
void _solve_impl(const Rhs& b, Dest& x) const
{
x = m_invdiag.array() * b.array() ;
}
template<typename Rhs> inline const Solve<DiagonalPreconditioner, Rhs>
solve(const MatrixBase<Rhs>& b) const
{
eigen_assert(m_isInitialized && "DiagonalPreconditioner is not initialized.");
eigen_assert(m_invdiag.size()==b.rows()
&& "DiagonalPreconditioner::solve(): invalid number of rows of the right hand side matrix b");
return Solve<DiagonalPreconditioner, Rhs>(*this, b.derived());
}
ComputationInfo info() { return Success; }
protected:
Vector m_invdiag;
bool m_isInitialized;
};
/** \ingroup IterativeLinearSolvers_Module
* \brief Jacobi preconditioner for LeastSquaresConjugateGradient
*
* This class allows to approximately solve for A' A x = A' b problems assuming A' A is a diagonal matrix.
* In other words, this preconditioner neglects all off diagonal entries and, in Eigen's language, solves for:
\code
(A.adjoint() * A).diagonal().asDiagonal() * x = b
\endcode
*
* \tparam _Scalar the type of the scalar.
*
* \implsparsesolverconcept
*
* The diagonal entries are pre-inverted and stored into a dense vector.
*
* \sa class LeastSquaresConjugateGradient, class DiagonalPreconditioner
*/
template <typename _Scalar>
class LeastSquareDiagonalPreconditioner : public DiagonalPreconditioner<_Scalar>
{
typedef _Scalar Scalar;
typedef typename NumTraits<Scalar>::Real RealScalar;
typedef DiagonalPreconditioner<_Scalar> Base;
using Base::m_invdiag;
public:
LeastSquareDiagonalPreconditioner() : Base() {}
template<typename MatType>
explicit LeastSquareDiagonalPreconditioner(const MatType& mat) : Base()
{
compute(mat);
}
template<typename MatType>
LeastSquareDiagonalPreconditioner& analyzePattern(const MatType& )
{
return *this;
}
template<typename MatType>
LeastSquareDiagonalPreconditioner& factorize(const MatType& mat)
{
// Compute the inverse squared-norm of each column of mat
m_invdiag.resize(mat.cols());
if(MatType::IsRowMajor)
{
m_invdiag.setZero();
for(Index j=0; j<mat.outerSize(); ++j)
{
for(typename MatType::InnerIterator it(mat,j); it; ++it)
m_invdiag(it.index()) += numext::abs2(it.value());
}
for(Index j=0; j<mat.cols(); ++j)
if(numext::real(m_invdiag(j))>RealScalar(0))
m_invdiag(j) = RealScalar(1)/numext::real(m_invdiag(j));
}
else
{
for(Index j=0; j<mat.outerSize(); ++j)
{
RealScalar sum = mat.col(j).squaredNorm();
if(sum>RealScalar(0))
m_invdiag(j) = RealScalar(1)/sum;
else
m_invdiag(j) = RealScalar(1);
}
}
Base::m_isInitialized = true;
return *this;
}
template<typename MatType>
LeastSquareDiagonalPreconditioner& compute(const MatType& mat)
{
return factorize(mat);
}
ComputationInfo info() { return Success; }
protected:
};
/** \ingroup IterativeLinearSolvers_Module
* \brief A naive preconditioner which approximates any matrix as the identity matrix
*
* \implsparsesolverconcept
*
* \sa class DiagonalPreconditioner
*/
class IdentityPreconditioner
{
public:
IdentityPreconditioner() {}
template<typename MatrixType>
explicit IdentityPreconditioner(const MatrixType& ) {}
template<typename MatrixType>
IdentityPreconditioner& analyzePattern(const MatrixType& ) { return *this; }
template<typename MatrixType>
IdentityPreconditioner& factorize(const MatrixType& ) { return *this; }
template<typename MatrixType>
IdentityPreconditioner& compute(const MatrixType& ) { return *this; }
template<typename Rhs>
inline const Rhs& solve(const Rhs& b) const { return b; }
ComputationInfo info() { return Success; }
};
} // end namespace Eigen
#endif // EIGEN_BASIC_PRECONDITIONERS_H

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// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2011-2014 Gael Guennebaud <gael.guennebaud@inria.fr>
// Copyright (C) 2012 Désiré Nuentsa-Wakam <desire.nuentsa_wakam@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_BICGSTAB_H
#define EIGEN_BICGSTAB_H
namespace Eigen {
namespace internal {
/** \internal Low-level bi conjugate gradient stabilized algorithm
* \param mat The matrix A
* \param rhs The right hand side vector b
* \param x On input and initial solution, on output the computed solution.
* \param precond A preconditioner being able to efficiently solve for an
* approximation of Ax=b (regardless of b)
* \param iters On input the max number of iteration, on output the number of performed iterations.
* \param tol_error On input the tolerance error, on output an estimation of the relative error.
* \return false in the case of numerical issue, for example a break down of BiCGSTAB.
*/
template<typename MatrixType, typename Rhs, typename Dest, typename Preconditioner>
bool bicgstab(const MatrixType& mat, const Rhs& rhs, Dest& x,
const Preconditioner& precond, Index& iters,
typename Dest::RealScalar& tol_error)
{
using std::sqrt;
using std::abs;
typedef typename Dest::RealScalar RealScalar;
typedef typename Dest::Scalar Scalar;
typedef Matrix<Scalar,Dynamic,1> VectorType;
RealScalar tol = tol_error;
Index maxIters = iters;
Index n = mat.cols();
VectorType r = rhs - mat * x;
VectorType r0 = r;
RealScalar r0_sqnorm = r0.squaredNorm();
RealScalar rhs_sqnorm = rhs.squaredNorm();
if(rhs_sqnorm == 0)
{
x.setZero();
return true;
}
Scalar rho = 1;
Scalar alpha = 1;
Scalar w = 1;
VectorType v = VectorType::Zero(n), p = VectorType::Zero(n);
VectorType y(n), z(n);
VectorType kt(n), ks(n);
VectorType s(n), t(n);
RealScalar tol2 = tol*tol*rhs_sqnorm;
RealScalar eps2 = NumTraits<Scalar>::epsilon()*NumTraits<Scalar>::epsilon();
Index i = 0;
Index restarts = 0;
while ( r.squaredNorm() > tol2 && i<maxIters )
{
Scalar rho_old = rho;
rho = r0.dot(r);
if (abs(rho) < eps2*r0_sqnorm)
{
// The new residual vector became too orthogonal to the arbitrarily chosen direction r0
// Let's restart with a new r0:
r = rhs - mat * x;
r0 = r;
rho = r0_sqnorm = r.squaredNorm();
if(restarts++ == 0)
i = 0;
}
Scalar beta = (rho/rho_old) * (alpha / w);
p = r + beta * (p - w * v);
y = precond.solve(p);
v.noalias() = mat * y;
alpha = rho / r0.dot(v);
s = r - alpha * v;
z = precond.solve(s);
t.noalias() = mat * z;
RealScalar tmp = t.squaredNorm();
if(tmp>RealScalar(0))
w = t.dot(s) / tmp;
else
w = Scalar(0);
x += alpha * y + w * z;
r = s - w * t;
++i;
}
tol_error = sqrt(r.squaredNorm()/rhs_sqnorm);
iters = i;
return true;
}
}
template< typename _MatrixType,
typename _Preconditioner = DiagonalPreconditioner<typename _MatrixType::Scalar> >
class BiCGSTAB;
namespace internal {
template< typename _MatrixType, typename _Preconditioner>
struct traits<BiCGSTAB<_MatrixType,_Preconditioner> >
{
typedef _MatrixType MatrixType;
typedef _Preconditioner Preconditioner;
};
}
/** \ingroup IterativeLinearSolvers_Module
* \brief A bi conjugate gradient stabilized solver for sparse square problems
*
* This class allows to solve for A.x = b sparse linear problems using a bi conjugate gradient
* stabilized algorithm. The vectors x and b can be either dense or sparse.
*
* \tparam _MatrixType the type of the sparse matrix A, can be a dense or a sparse matrix.
* \tparam _Preconditioner the type of the preconditioner. Default is DiagonalPreconditioner
*
* \implsparsesolverconcept
*
* The maximal number of iterations and tolerance value can be controlled via the setMaxIterations()
* and setTolerance() methods. The defaults are the size of the problem for the maximal number of iterations
* and NumTraits<Scalar>::epsilon() for the tolerance.
*
* The tolerance corresponds to the relative residual error: |Ax-b|/|b|
*
* \b Performance: when using sparse matrices, best performance is achied for a row-major sparse matrix format.
* Moreover, in this case multi-threading can be exploited if the user code is compiled with OpenMP enabled.
* See \ref TopicMultiThreading for details.
*
* This class can be used as the direct solver classes. Here is a typical usage example:
* \include BiCGSTAB_simple.cpp
*
* By default the iterations start with x=0 as an initial guess of the solution.
* One can control the start using the solveWithGuess() method.
*
* BiCGSTAB can also be used in a matrix-free context, see the following \link MatrixfreeSolverExample example \endlink.
*
* \sa class SimplicialCholesky, DiagonalPreconditioner, IdentityPreconditioner
*/
template< typename _MatrixType, typename _Preconditioner>
class BiCGSTAB : public IterativeSolverBase<BiCGSTAB<_MatrixType,_Preconditioner> >
{
typedef IterativeSolverBase<BiCGSTAB> Base;
using Base::matrix;
using Base::m_error;
using Base::m_iterations;
using Base::m_info;
using Base::m_isInitialized;
public:
typedef _MatrixType MatrixType;
typedef typename MatrixType::Scalar Scalar;
typedef typename MatrixType::RealScalar RealScalar;
typedef _Preconditioner Preconditioner;
public:
/** Default constructor. */
BiCGSTAB() : Base() {}
/** Initialize the solver with matrix \a A for further \c Ax=b solving.
*
* This constructor is a shortcut for the default constructor followed
* by a call to compute().
*
* \warning this class stores a reference to the matrix A as well as some
* precomputed values that depend on it. Therefore, if \a A is changed
* this class becomes invalid. Call compute() to update it with the new
* matrix A, or modify a copy of A.
*/
template<typename MatrixDerived>
explicit BiCGSTAB(const EigenBase<MatrixDerived>& A) : Base(A.derived()) {}
~BiCGSTAB() {}
/** \internal */
template<typename Rhs,typename Dest>
void _solve_with_guess_impl(const Rhs& b, Dest& x) const
{
bool failed = false;
for(Index j=0; j<b.cols(); ++j)
{
m_iterations = Base::maxIterations();
m_error = Base::m_tolerance;
typename Dest::ColXpr xj(x,j);
if(!internal::bicgstab(matrix(), b.col(j), xj, Base::m_preconditioner, m_iterations, m_error))
failed = true;
}
m_info = failed ? NumericalIssue
: m_error <= Base::m_tolerance ? Success
: NoConvergence;
m_isInitialized = true;
}
/** \internal */
using Base::_solve_impl;
template<typename Rhs,typename Dest>
void _solve_impl(const MatrixBase<Rhs>& b, Dest& x) const
{
x.resize(this->rows(),b.cols());
x.setZero();
_solve_with_guess_impl(b,x);
}
protected:
};
} // end namespace Eigen
#endif // EIGEN_BICGSTAB_H

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// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2011-2014 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_CONJUGATE_GRADIENT_H
#define EIGEN_CONJUGATE_GRADIENT_H
namespace Eigen {
namespace internal {
/** \internal Low-level conjugate gradient algorithm
* \param mat The matrix A
* \param rhs The right hand side vector b
* \param x On input and initial solution, on output the computed solution.
* \param precond A preconditioner being able to efficiently solve for an
* approximation of Ax=b (regardless of b)
* \param iters On input the max number of iteration, on output the number of performed iterations.
* \param tol_error On input the tolerance error, on output an estimation of the relative error.
*/
template<typename MatrixType, typename Rhs, typename Dest, typename Preconditioner>
EIGEN_DONT_INLINE
void conjugate_gradient(const MatrixType& mat, const Rhs& rhs, Dest& x,
const Preconditioner& precond, Index& iters,
typename Dest::RealScalar& tol_error)
{
using std::sqrt;
using std::abs;
typedef typename Dest::RealScalar RealScalar;
typedef typename Dest::Scalar Scalar;
typedef Matrix<Scalar,Dynamic,1> VectorType;
RealScalar tol = tol_error;
Index maxIters = iters;
Index n = mat.cols();
VectorType residual = rhs - mat * x; //initial residual
RealScalar rhsNorm2 = rhs.squaredNorm();
if(rhsNorm2 == 0)
{
x.setZero();
iters = 0;
tol_error = 0;
return;
}
const RealScalar considerAsZero = (std::numeric_limits<RealScalar>::min)();
RealScalar threshold = numext::maxi(tol*tol*rhsNorm2,considerAsZero);
RealScalar residualNorm2 = residual.squaredNorm();
if (residualNorm2 < threshold)
{
iters = 0;
tol_error = sqrt(residualNorm2 / rhsNorm2);
return;
}
VectorType p(n);
p = precond.solve(residual); // initial search direction
VectorType z(n), tmp(n);
RealScalar absNew = numext::real(residual.dot(p)); // the square of the absolute value of r scaled by invM
Index i = 0;
while(i < maxIters)
{
tmp.noalias() = mat * p; // the bottleneck of the algorithm
Scalar alpha = absNew / p.dot(tmp); // the amount we travel on dir
x += alpha * p; // update solution
residual -= alpha * tmp; // update residual
residualNorm2 = residual.squaredNorm();
if(residualNorm2 < threshold)
break;
z = precond.solve(residual); // approximately solve for "A z = residual"
RealScalar absOld = absNew;
absNew = numext::real(residual.dot(z)); // update the absolute value of r
RealScalar beta = absNew / absOld; // calculate the Gram-Schmidt value used to create the new search direction
p = z + beta * p; // update search direction
i++;
}
tol_error = sqrt(residualNorm2 / rhsNorm2);
iters = i;
}
}
template< typename _MatrixType, int _UpLo=Lower,
typename _Preconditioner = DiagonalPreconditioner<typename _MatrixType::Scalar> >
class ConjugateGradient;
namespace internal {
template< typename _MatrixType, int _UpLo, typename _Preconditioner>
struct traits<ConjugateGradient<_MatrixType,_UpLo,_Preconditioner> >
{
typedef _MatrixType MatrixType;
typedef _Preconditioner Preconditioner;
};
}
/** \ingroup IterativeLinearSolvers_Module
* \brief A conjugate gradient solver for sparse (or dense) self-adjoint problems
*
* This class allows to solve for A.x = b linear problems using an iterative conjugate gradient algorithm.
* The matrix A must be selfadjoint. The matrix A and the vectors x and b can be either dense or sparse.
*
* \tparam _MatrixType the type of the matrix A, can be a dense or a sparse matrix.
* \tparam _UpLo the triangular part that will be used for the computations. It can be Lower,
* \c Upper, or \c Lower|Upper in which the full matrix entries will be considered.
* Default is \c Lower, best performance is \c Lower|Upper.
* \tparam _Preconditioner the type of the preconditioner. Default is DiagonalPreconditioner
*
* \implsparsesolverconcept
*
* The maximal number of iterations and tolerance value can be controlled via the setMaxIterations()
* and setTolerance() methods. The defaults are the size of the problem for the maximal number of iterations
* and NumTraits<Scalar>::epsilon() for the tolerance.
*
* The tolerance corresponds to the relative residual error: |Ax-b|/|b|
*
* \b Performance: Even though the default value of \c _UpLo is \c Lower, significantly higher performance is
* achieved when using a complete matrix and \b Lower|Upper as the \a _UpLo template parameter. Moreover, in this
* case multi-threading can be exploited if the user code is compiled with OpenMP enabled.
* See \ref TopicMultiThreading for details.
*
* This class can be used as the direct solver classes. Here is a typical usage example:
\code
int n = 10000;
VectorXd x(n), b(n);
SparseMatrix<double> A(n,n);
// fill A and b
ConjugateGradient<SparseMatrix<double>, Lower|Upper> cg;
cg.compute(A);
x = cg.solve(b);
std::cout << "#iterations: " << cg.iterations() << std::endl;
std::cout << "estimated error: " << cg.error() << std::endl;
// update b, and solve again
x = cg.solve(b);
\endcode
*
* By default the iterations start with x=0 as an initial guess of the solution.
* One can control the start using the solveWithGuess() method.
*
* ConjugateGradient can also be used in a matrix-free context, see the following \link MatrixfreeSolverExample example \endlink.
*
* \sa class LeastSquaresConjugateGradient, class SimplicialCholesky, DiagonalPreconditioner, IdentityPreconditioner
*/
template< typename _MatrixType, int _UpLo, typename _Preconditioner>
class ConjugateGradient : public IterativeSolverBase<ConjugateGradient<_MatrixType,_UpLo,_Preconditioner> >
{
typedef IterativeSolverBase<ConjugateGradient> Base;
using Base::matrix;
using Base::m_error;
using Base::m_iterations;
using Base::m_info;
using Base::m_isInitialized;
public:
typedef _MatrixType MatrixType;
typedef typename MatrixType::Scalar Scalar;
typedef typename MatrixType::RealScalar RealScalar;
typedef _Preconditioner Preconditioner;
enum {
UpLo = _UpLo
};
public:
/** Default constructor. */
ConjugateGradient() : Base() {}
/** Initialize the solver with matrix \a A for further \c Ax=b solving.
*
* This constructor is a shortcut for the default constructor followed
* by a call to compute().
*
* \warning this class stores a reference to the matrix A as well as some
* precomputed values that depend on it. Therefore, if \a A is changed
* this class becomes invalid. Call compute() to update it with the new
* matrix A, or modify a copy of A.
*/
template<typename MatrixDerived>
explicit ConjugateGradient(const EigenBase<MatrixDerived>& A) : Base(A.derived()) {}
~ConjugateGradient() {}
/** \internal */
template<typename Rhs,typename Dest>
void _solve_with_guess_impl(const Rhs& b, Dest& x) const
{
typedef typename Base::MatrixWrapper MatrixWrapper;
typedef typename Base::ActualMatrixType ActualMatrixType;
enum {
TransposeInput = (!MatrixWrapper::MatrixFree)
&& (UpLo==(Lower|Upper))
&& (!MatrixType::IsRowMajor)
&& (!NumTraits<Scalar>::IsComplex)
};
typedef typename internal::conditional<TransposeInput,Transpose<const ActualMatrixType>, ActualMatrixType const&>::type RowMajorWrapper;
EIGEN_STATIC_ASSERT(EIGEN_IMPLIES(MatrixWrapper::MatrixFree,UpLo==(Lower|Upper)),MATRIX_FREE_CONJUGATE_GRADIENT_IS_COMPATIBLE_WITH_UPPER_UNION_LOWER_MODE_ONLY);
typedef typename internal::conditional<UpLo==(Lower|Upper),
RowMajorWrapper,
typename MatrixWrapper::template ConstSelfAdjointViewReturnType<UpLo>::Type
>::type SelfAdjointWrapper;
m_iterations = Base::maxIterations();
m_error = Base::m_tolerance;
for(Index j=0; j<b.cols(); ++j)
{
m_iterations = Base::maxIterations();
m_error = Base::m_tolerance;
typename Dest::ColXpr xj(x,j);
RowMajorWrapper row_mat(matrix());
internal::conjugate_gradient(SelfAdjointWrapper(row_mat), b.col(j), xj, Base::m_preconditioner, m_iterations, m_error);
}
m_isInitialized = true;
m_info = m_error <= Base::m_tolerance ? Success : NoConvergence;
}
/** \internal */
using Base::_solve_impl;
template<typename Rhs,typename Dest>
void _solve_impl(const MatrixBase<Rhs>& b, Dest& x) const
{
x.setZero();
_solve_with_guess_impl(b.derived(),x);
}
protected:
};
} // end namespace Eigen
#endif // EIGEN_CONJUGATE_GRADIENT_H

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// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2012 Désiré Nuentsa-Wakam <desire.nuentsa_wakam@inria.fr>
// Copyright (C) 2015 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_INCOMPLETE_CHOlESKY_H
#define EIGEN_INCOMPLETE_CHOlESKY_H
#include <vector>
#include <list>
namespace Eigen {
/**
* \brief Modified Incomplete Cholesky with dual threshold
*
* References : C-J. Lin and J. J. Moré, Incomplete Cholesky Factorizations with
* Limited memory, SIAM J. Sci. Comput. 21(1), pp. 24-45, 1999
*
* \tparam Scalar the scalar type of the input matrices
* \tparam _UpLo The triangular part that will be used for the computations. It can be Lower
* or Upper. Default is Lower.
* \tparam _OrderingType The ordering method to use, either AMDOrdering<> or NaturalOrdering<>. Default is AMDOrdering<int>,
* unless EIGEN_MPL2_ONLY is defined, in which case the default is NaturalOrdering<int>.
*
* \implsparsesolverconcept
*
* It performs the following incomplete factorization: \f$ S P A P' S \approx L L' \f$
* where L is a lower triangular factor, S is a diagonal scaling matrix, and P is a
* fill-in reducing permutation as computed by the ordering method.
*
* \b Shifting \b strategy: Let \f$ B = S P A P' S \f$ be the scaled matrix on which the factorization is carried out,
* and \f$ \beta \f$ be the minimum value of the diagonal. If \f$ \beta > 0 \f$ then, the factorization is directly performed
* on the matrix B. Otherwise, the factorization is performed on the shifted matrix \f$ B + (\sigma+|\beta| I \f$ where
* \f$ \sigma \f$ is the initial shift value as returned and set by setInitialShift() method. The default value is \f$ \sigma = 10^{-3} \f$.
* If the factorization fails, then the shift in doubled until it succeed or a maximum of ten attempts. If it still fails, as returned by
* the info() method, then you can either increase the initial shift, or better use another preconditioning technique.
*
*/
template <typename Scalar, int _UpLo = Lower, typename _OrderingType =
#ifndef EIGEN_MPL2_ONLY
AMDOrdering<int>
#else
NaturalOrdering<int>
#endif
>
class IncompleteCholesky : public SparseSolverBase<IncompleteCholesky<Scalar,_UpLo,_OrderingType> >
{
protected:
typedef SparseSolverBase<IncompleteCholesky<Scalar,_UpLo,_OrderingType> > Base;
using Base::m_isInitialized;
public:
typedef typename NumTraits<Scalar>::Real RealScalar;
typedef _OrderingType OrderingType;
typedef typename OrderingType::PermutationType PermutationType;
typedef typename PermutationType::StorageIndex StorageIndex;
typedef SparseMatrix<Scalar,ColMajor,StorageIndex> FactorType;
typedef Matrix<Scalar,Dynamic,1> VectorSx;
typedef Matrix<RealScalar,Dynamic,1> VectorRx;
typedef Matrix<StorageIndex,Dynamic, 1> VectorIx;
typedef std::vector<std::list<StorageIndex> > VectorList;
enum { UpLo = _UpLo };
enum {
ColsAtCompileTime = Dynamic,
MaxColsAtCompileTime = Dynamic
};
public:
/** Default constructor leaving the object in a partly non-initialized stage.
*
* You must call compute() or the pair analyzePattern()/factorize() to make it valid.
*
* \sa IncompleteCholesky(const MatrixType&)
*/
IncompleteCholesky() : m_initialShift(1e-3),m_factorizationIsOk(false) {}
/** Constructor computing the incomplete factorization for the given matrix \a matrix.
*/
template<typename MatrixType>
IncompleteCholesky(const MatrixType& matrix) : m_initialShift(1e-3),m_factorizationIsOk(false)
{
compute(matrix);
}
/** \returns number of rows of the factored matrix */
Index rows() const { return m_L.rows(); }
/** \returns number of columns of the factored matrix */
Index cols() const { return m_L.cols(); }
/** \brief Reports whether previous computation was successful.
*
* It triggers an assertion if \c *this has not been initialized through the respective constructor,
* or a call to compute() or analyzePattern().
*
* \returns \c Success if computation was successful,
* \c NumericalIssue if the matrix appears to be negative.
*/
ComputationInfo info() const
{
eigen_assert(m_isInitialized && "IncompleteCholesky is not initialized.");
return m_info;
}
/** \brief Set the initial shift parameter \f$ \sigma \f$.
*/
void setInitialShift(RealScalar shift) { m_initialShift = shift; }
/** \brief Computes the fill reducing permutation vector using the sparsity pattern of \a mat
*/
template<typename MatrixType>
void analyzePattern(const MatrixType& mat)
{
OrderingType ord;
PermutationType pinv;
ord(mat.template selfadjointView<UpLo>(), pinv);
if(pinv.size()>0) m_perm = pinv.inverse();
else m_perm.resize(0);
m_L.resize(mat.rows(), mat.cols());
m_analysisIsOk = true;
m_isInitialized = true;
m_info = Success;
}
/** \brief Performs the numerical factorization of the input matrix \a mat
*
* The method analyzePattern() or compute() must have been called beforehand
* with a matrix having the same pattern.
*
* \sa compute(), analyzePattern()
*/
template<typename MatrixType>
void factorize(const MatrixType& mat);
/** Computes or re-computes the incomplete Cholesky factorization of the input matrix \a mat
*
* It is a shortcut for a sequential call to the analyzePattern() and factorize() methods.
*
* \sa analyzePattern(), factorize()
*/
template<typename MatrixType>
void compute(const MatrixType& mat)
{
analyzePattern(mat);
factorize(mat);
}
// internal
template<typename Rhs, typename Dest>
void _solve_impl(const Rhs& b, Dest& x) const
{
eigen_assert(m_factorizationIsOk && "factorize() should be called first");
if (m_perm.rows() == b.rows()) x = m_perm * b;
else x = b;
x = m_scale.asDiagonal() * x;
x = m_L.template triangularView<Lower>().solve(x);
x = m_L.adjoint().template triangularView<Upper>().solve(x);
x = m_scale.asDiagonal() * x;
if (m_perm.rows() == b.rows())
x = m_perm.inverse() * x;
}
/** \returns the sparse lower triangular factor L */
const FactorType& matrixL() const { eigen_assert("m_factorizationIsOk"); return m_L; }
/** \returns a vector representing the scaling factor S */
const VectorRx& scalingS() const { eigen_assert("m_factorizationIsOk"); return m_scale; }
/** \returns the fill-in reducing permutation P (can be empty for a natural ordering) */
const PermutationType& permutationP() const { eigen_assert("m_analysisIsOk"); return m_perm; }
protected:
FactorType m_L; // The lower part stored in CSC
VectorRx m_scale; // The vector for scaling the matrix
RealScalar m_initialShift; // The initial shift parameter
bool m_analysisIsOk;
bool m_factorizationIsOk;
ComputationInfo m_info;
PermutationType m_perm;
private:
inline void updateList(Ref<const VectorIx> colPtr, Ref<VectorIx> rowIdx, Ref<VectorSx> vals, const Index& col, const Index& jk, VectorIx& firstElt, VectorList& listCol);
};
// Based on the following paper:
// C-J. Lin and J. J. Moré, Incomplete Cholesky Factorizations with
// Limited memory, SIAM J. Sci. Comput. 21(1), pp. 24-45, 1999
// http://ftp.mcs.anl.gov/pub/tech_reports/reports/P682.pdf
template<typename Scalar, int _UpLo, typename OrderingType>
template<typename _MatrixType>
void IncompleteCholesky<Scalar,_UpLo, OrderingType>::factorize(const _MatrixType& mat)
{
using std::sqrt;
eigen_assert(m_analysisIsOk && "analyzePattern() should be called first");
// Dropping strategy : Keep only the p largest elements per column, where p is the number of elements in the column of the original matrix. Other strategies will be added
// Apply the fill-reducing permutation computed in analyzePattern()
if (m_perm.rows() == mat.rows() ) // To detect the null permutation
{
// The temporary is needed to make sure that the diagonal entry is properly sorted
FactorType tmp(mat.rows(), mat.cols());
tmp = mat.template selfadjointView<_UpLo>().twistedBy(m_perm);
m_L.template selfadjointView<Lower>() = tmp.template selfadjointView<Lower>();
}
else
{
m_L.template selfadjointView<Lower>() = mat.template selfadjointView<_UpLo>();
}
Index n = m_L.cols();
Index nnz = m_L.nonZeros();
Map<VectorSx> vals(m_L.valuePtr(), nnz); //values
Map<VectorIx> rowIdx(m_L.innerIndexPtr(), nnz); //Row indices
Map<VectorIx> colPtr( m_L.outerIndexPtr(), n+1); // Pointer to the beginning of each row
VectorIx firstElt(n-1); // for each j, points to the next entry in vals that will be used in the factorization
VectorList listCol(n); // listCol(j) is a linked list of columns to update column j
VectorSx col_vals(n); // Store a nonzero values in each column
VectorIx col_irow(n); // Row indices of nonzero elements in each column
VectorIx col_pattern(n);
col_pattern.fill(-1);
StorageIndex col_nnz;
// Computes the scaling factors
m_scale.resize(n);
m_scale.setZero();
for (Index j = 0; j < n; j++)
for (Index k = colPtr[j]; k < colPtr[j+1]; k++)
{
m_scale(j) += numext::abs2(vals(k));
if(rowIdx[k]!=j)
m_scale(rowIdx[k]) += numext::abs2(vals(k));
}
m_scale = m_scale.cwiseSqrt().cwiseSqrt();
for (Index j = 0; j < n; ++j)
if(m_scale(j)>(std::numeric_limits<RealScalar>::min)())
m_scale(j) = RealScalar(1)/m_scale(j);
else
m_scale(j) = 1;
// TODO disable scaling if not needed, i.e., if it is roughly uniform? (this will make solve() faster)
// Scale and compute the shift for the matrix
RealScalar mindiag = NumTraits<RealScalar>::highest();
for (Index j = 0; j < n; j++)
{
for (Index k = colPtr[j]; k < colPtr[j+1]; k++)
vals[k] *= (m_scale(j)*m_scale(rowIdx[k]));
eigen_internal_assert(rowIdx[colPtr[j]]==j && "IncompleteCholesky: only the lower triangular part must be stored");
mindiag = numext::mini(numext::real(vals[colPtr[j]]), mindiag);
}
FactorType L_save = m_L;
RealScalar shift = 0;
if(mindiag <= RealScalar(0.))
shift = m_initialShift - mindiag;
m_info = NumericalIssue;
// Try to perform the incomplete factorization using the current shift
int iter = 0;
do
{
// Apply the shift to the diagonal elements of the matrix
for (Index j = 0; j < n; j++)
vals[colPtr[j]] += shift;
// jki version of the Cholesky factorization
Index j=0;
for (; j < n; ++j)
{
// Left-looking factorization of the j-th column
// First, load the j-th column into col_vals
Scalar diag = vals[colPtr[j]]; // It is assumed that only the lower part is stored
col_nnz = 0;
for (Index i = colPtr[j] + 1; i < colPtr[j+1]; i++)
{
StorageIndex l = rowIdx[i];
col_vals(col_nnz) = vals[i];
col_irow(col_nnz) = l;
col_pattern(l) = col_nnz;
col_nnz++;
}
{
typename std::list<StorageIndex>::iterator k;
// Browse all previous columns that will update column j
for(k = listCol[j].begin(); k != listCol[j].end(); k++)
{
Index jk = firstElt(*k); // First element to use in the column
eigen_internal_assert(rowIdx[jk]==j);
Scalar v_j_jk = numext::conj(vals[jk]);
jk += 1;
for (Index i = jk; i < colPtr[*k+1]; i++)
{
StorageIndex l = rowIdx[i];
if(col_pattern[l]<0)
{
col_vals(col_nnz) = vals[i] * v_j_jk;
col_irow[col_nnz] = l;
col_pattern(l) = col_nnz;
col_nnz++;
}
else
col_vals(col_pattern[l]) -= vals[i] * v_j_jk;
}
updateList(colPtr,rowIdx,vals, *k, jk, firstElt, listCol);
}
}
// Scale the current column
if(numext::real(diag) <= 0)
{
if(++iter>=10)
return;
// increase shift
shift = numext::maxi(m_initialShift,RealScalar(2)*shift);
// restore m_L, col_pattern, and listCol
vals = Map<const VectorSx>(L_save.valuePtr(), nnz);
rowIdx = Map<const VectorIx>(L_save.innerIndexPtr(), nnz);
colPtr = Map<const VectorIx>(L_save.outerIndexPtr(), n+1);
col_pattern.fill(-1);
for(Index i=0; i<n; ++i)
listCol[i].clear();
break;
}
RealScalar rdiag = sqrt(numext::real(diag));
vals[colPtr[j]] = rdiag;
for (Index k = 0; k<col_nnz; ++k)
{
Index i = col_irow[k];
//Scale
col_vals(k) /= rdiag;
//Update the remaining diagonals with col_vals
vals[colPtr[i]] -= numext::abs2(col_vals(k));
}
// Select the largest p elements
// p is the original number of elements in the column (without the diagonal)
Index p = colPtr[j+1] - colPtr[j] - 1 ;
Ref<VectorSx> cvals = col_vals.head(col_nnz);
Ref<VectorIx> cirow = col_irow.head(col_nnz);
internal::QuickSplit(cvals,cirow, p);
// Insert the largest p elements in the matrix
Index cpt = 0;
for (Index i = colPtr[j]+1; i < colPtr[j+1]; i++)
{
vals[i] = col_vals(cpt);
rowIdx[i] = col_irow(cpt);
// restore col_pattern:
col_pattern(col_irow(cpt)) = -1;
cpt++;
}
// Get the first smallest row index and put it after the diagonal element
Index jk = colPtr(j)+1;
updateList(colPtr,rowIdx,vals,j,jk,firstElt,listCol);
}
if(j==n)
{
m_factorizationIsOk = true;
m_info = Success;
}
} while(m_info!=Success);
}
template<typename Scalar, int _UpLo, typename OrderingType>
inline void IncompleteCholesky<Scalar,_UpLo, OrderingType>::updateList(Ref<const VectorIx> colPtr, Ref<VectorIx> rowIdx, Ref<VectorSx> vals, const Index& col, const Index& jk, VectorIx& firstElt, VectorList& listCol)
{
if (jk < colPtr(col+1) )
{
Index p = colPtr(col+1) - jk;
Index minpos;
rowIdx.segment(jk,p).minCoeff(&minpos);
minpos += jk;
if (rowIdx(minpos) != rowIdx(jk))
{
//Swap
std::swap(rowIdx(jk),rowIdx(minpos));
std::swap(vals(jk),vals(minpos));
}
firstElt(col) = internal::convert_index<StorageIndex,Index>(jk);
listCol[rowIdx(jk)].push_back(internal::convert_index<StorageIndex,Index>(col));
}
}
} // end namespace Eigen
#endif

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@@ -0,0 +1,462 @@
// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2012 Désiré Nuentsa-Wakam <desire.nuentsa_wakam@inria.fr>
// 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_INCOMPLETE_LUT_H
#define EIGEN_INCOMPLETE_LUT_H
namespace Eigen {
namespace internal {
/** \internal
* Compute a quick-sort split of a vector
* On output, the vector row is permuted such that its elements satisfy
* abs(row(i)) >= abs(row(ncut)) if i<ncut
* abs(row(i)) <= abs(row(ncut)) if i>ncut
* \param row The vector of values
* \param ind The array of index for the elements in @p row
* \param ncut The number of largest elements to keep
**/
template <typename VectorV, typename VectorI>
Index QuickSplit(VectorV &row, VectorI &ind, Index ncut)
{
typedef typename VectorV::RealScalar RealScalar;
using std::swap;
using std::abs;
Index mid;
Index n = row.size(); /* length of the vector */
Index first, last ;
ncut--; /* to fit the zero-based indices */
first = 0;
last = n-1;
if (ncut < first || ncut > last ) return 0;
do {
mid = first;
RealScalar abskey = abs(row(mid));
for (Index j = first + 1; j <= last; j++) {
if ( abs(row(j)) > abskey) {
++mid;
swap(row(mid), row(j));
swap(ind(mid), ind(j));
}
}
/* Interchange for the pivot element */
swap(row(mid), row(first));
swap(ind(mid), ind(first));
if (mid > ncut) last = mid - 1;
else if (mid < ncut ) first = mid + 1;
} while (mid != ncut );
return 0; /* mid is equal to ncut */
}
}// end namespace internal
/** \ingroup IterativeLinearSolvers_Module
* \class IncompleteLUT
* \brief Incomplete LU factorization with dual-threshold strategy
*
* \implsparsesolverconcept
*
* During the numerical factorization, two dropping rules are used :
* 1) any element whose magnitude is less than some tolerance is dropped.
* This tolerance is obtained by multiplying the input tolerance @p droptol
* by the average magnitude of all the original elements in the current row.
* 2) After the elimination of the row, only the @p fill largest elements in
* the L part and the @p fill largest elements in the U part are kept
* (in addition to the diagonal element ). Note that @p fill is computed from
* the input parameter @p fillfactor which is used the ratio to control the fill_in
* relatively to the initial number of nonzero elements.
*
* The two extreme cases are when @p droptol=0 (to keep all the @p fill*2 largest elements)
* and when @p fill=n/2 with @p droptol being different to zero.
*
* References : Yousef Saad, ILUT: A dual threshold incomplete LU factorization,
* Numerical Linear Algebra with Applications, 1(4), pp 387-402, 1994.
*
* NOTE : The following implementation is derived from the ILUT implementation
* in the SPARSKIT package, Copyright (C) 2005, the Regents of the University of Minnesota
* released under the terms of the GNU LGPL:
* http://www-users.cs.umn.edu/~saad/software/SPARSKIT/README
* However, Yousef Saad gave us permission to relicense his ILUT code to MPL2.
* See the Eigen mailing list archive, thread: ILUT, date: July 8, 2012:
* http://listengine.tuxfamily.org/lists.tuxfamily.org/eigen/2012/07/msg00064.html
* alternatively, on GMANE:
* http://comments.gmane.org/gmane.comp.lib.eigen/3302
*/
template <typename _Scalar, typename _StorageIndex = int>
class IncompleteLUT : public SparseSolverBase<IncompleteLUT<_Scalar, _StorageIndex> >
{
protected:
typedef SparseSolverBase<IncompleteLUT> Base;
using Base::m_isInitialized;
public:
typedef _Scalar Scalar;
typedef _StorageIndex StorageIndex;
typedef typename NumTraits<Scalar>::Real RealScalar;
typedef Matrix<Scalar,Dynamic,1> Vector;
typedef Matrix<StorageIndex,Dynamic,1> VectorI;
typedef SparseMatrix<Scalar,RowMajor,StorageIndex> FactorType;
enum {
ColsAtCompileTime = Dynamic,
MaxColsAtCompileTime = Dynamic
};
public:
IncompleteLUT()
: m_droptol(NumTraits<Scalar>::dummy_precision()), m_fillfactor(10),
m_analysisIsOk(false), m_factorizationIsOk(false)
{}
template<typename MatrixType>
explicit IncompleteLUT(const MatrixType& mat, const RealScalar& droptol=NumTraits<Scalar>::dummy_precision(), int fillfactor = 10)
: m_droptol(droptol),m_fillfactor(fillfactor),
m_analysisIsOk(false),m_factorizationIsOk(false)
{
eigen_assert(fillfactor != 0);
compute(mat);
}
Index rows() const { return m_lu.rows(); }
Index cols() const { return m_lu.cols(); }
/** \brief Reports whether previous computation was successful.
*
* \returns \c Success if computation was succesful,
* \c NumericalIssue if the matrix.appears to be negative.
*/
ComputationInfo info() const
{
eigen_assert(m_isInitialized && "IncompleteLUT is not initialized.");
return m_info;
}
template<typename MatrixType>
void analyzePattern(const MatrixType& amat);
template<typename MatrixType>
void factorize(const MatrixType& amat);
/**
* Compute an incomplete LU factorization with dual threshold on the matrix mat
* No pivoting is done in this version
*
**/
template<typename MatrixType>
IncompleteLUT& compute(const MatrixType& amat)
{
analyzePattern(amat);
factorize(amat);
return *this;
}
void setDroptol(const RealScalar& droptol);
void setFillfactor(int fillfactor);
template<typename Rhs, typename Dest>
void _solve_impl(const Rhs& b, Dest& x) const
{
x = m_Pinv * b;
x = m_lu.template triangularView<UnitLower>().solve(x);
x = m_lu.template triangularView<Upper>().solve(x);
x = m_P * x;
}
protected:
/** keeps off-diagonal entries; drops diagonal entries */
struct keep_diag {
inline bool operator() (const Index& row, const Index& col, const Scalar&) const
{
return row!=col;
}
};
protected:
FactorType m_lu;
RealScalar m_droptol;
int m_fillfactor;
bool m_analysisIsOk;
bool m_factorizationIsOk;
ComputationInfo m_info;
PermutationMatrix<Dynamic,Dynamic,StorageIndex> m_P; // Fill-reducing permutation
PermutationMatrix<Dynamic,Dynamic,StorageIndex> m_Pinv; // Inverse permutation
};
/**
* Set control parameter droptol
* \param droptol Drop any element whose magnitude is less than this tolerance
**/
template<typename Scalar, typename StorageIndex>
void IncompleteLUT<Scalar,StorageIndex>::setDroptol(const RealScalar& droptol)
{
this->m_droptol = droptol;
}
/**
* Set control parameter fillfactor
* \param fillfactor This is used to compute the number @p fill_in of largest elements to keep on each row.
**/
template<typename Scalar, typename StorageIndex>
void IncompleteLUT<Scalar,StorageIndex>::setFillfactor(int fillfactor)
{
this->m_fillfactor = fillfactor;
}
template <typename Scalar, typename StorageIndex>
template<typename _MatrixType>
void IncompleteLUT<Scalar,StorageIndex>::analyzePattern(const _MatrixType& amat)
{
// Compute the Fill-reducing permutation
// Since ILUT does not perform any numerical pivoting,
// it is highly preferable to keep the diagonal through symmetric permutations.
#ifndef EIGEN_MPL2_ONLY
// To this end, let's symmetrize the pattern and perform AMD on it.
SparseMatrix<Scalar,ColMajor, StorageIndex> mat1 = amat;
SparseMatrix<Scalar,ColMajor, StorageIndex> mat2 = amat.transpose();
// FIXME for a matrix with nearly symmetric pattern, mat2+mat1 is the appropriate choice.
// on the other hand for a really non-symmetric pattern, mat2*mat1 should be prefered...
SparseMatrix<Scalar,ColMajor, StorageIndex> AtA = mat2 + mat1;
AMDOrdering<StorageIndex> ordering;
ordering(AtA,m_P);
m_Pinv = m_P.inverse(); // cache the inverse permutation
#else
// If AMD is not available, (MPL2-only), then let's use the slower COLAMD routine.
SparseMatrix<Scalar,ColMajor, StorageIndex> mat1 = amat;
COLAMDOrdering<StorageIndex> ordering;
ordering(mat1,m_Pinv);
m_P = m_Pinv.inverse();
#endif
m_analysisIsOk = true;
m_factorizationIsOk = false;
m_isInitialized = true;
}
template <typename Scalar, typename StorageIndex>
template<typename _MatrixType>
void IncompleteLUT<Scalar,StorageIndex>::factorize(const _MatrixType& amat)
{
using std::sqrt;
using std::swap;
using std::abs;
using internal::convert_index;
eigen_assert((amat.rows() == amat.cols()) && "The factorization should be done on a square matrix");
Index n = amat.cols(); // Size of the matrix
m_lu.resize(n,n);
// Declare Working vectors and variables
Vector u(n) ; // real values of the row -- maximum size is n --
VectorI ju(n); // column position of the values in u -- maximum size is n
VectorI jr(n); // Indicate the position of the nonzero elements in the vector u -- A zero location is indicated by -1
// Apply the fill-reducing permutation
eigen_assert(m_analysisIsOk && "You must first call analyzePattern()");
SparseMatrix<Scalar,RowMajor, StorageIndex> mat;
mat = amat.twistedBy(m_Pinv);
// Initialization
jr.fill(-1);
ju.fill(0);
u.fill(0);
// number of largest elements to keep in each row:
Index fill_in = (amat.nonZeros()*m_fillfactor)/n + 1;
if (fill_in > n) fill_in = n;
// number of largest nonzero elements to keep in the L and the U part of the current row:
Index nnzL = fill_in/2;
Index nnzU = nnzL;
m_lu.reserve(n * (nnzL + nnzU + 1));
// global loop over the rows of the sparse matrix
for (Index ii = 0; ii < n; ii++)
{
// 1 - copy the lower and the upper part of the row i of mat in the working vector u
Index sizeu = 1; // number of nonzero elements in the upper part of the current row
Index sizel = 0; // number of nonzero elements in the lower part of the current row
ju(ii) = convert_index<StorageIndex>(ii);
u(ii) = 0;
jr(ii) = convert_index<StorageIndex>(ii);
RealScalar rownorm = 0;
typename FactorType::InnerIterator j_it(mat, ii); // Iterate through the current row ii
for (; j_it; ++j_it)
{
Index k = j_it.index();
if (k < ii)
{
// copy the lower part
ju(sizel) = convert_index<StorageIndex>(k);
u(sizel) = j_it.value();
jr(k) = convert_index<StorageIndex>(sizel);
++sizel;
}
else if (k == ii)
{
u(ii) = j_it.value();
}
else
{
// copy the upper part
Index jpos = ii + sizeu;
ju(jpos) = convert_index<StorageIndex>(k);
u(jpos) = j_it.value();
jr(k) = convert_index<StorageIndex>(jpos);
++sizeu;
}
rownorm += numext::abs2(j_it.value());
}
// 2 - detect possible zero row
if(rownorm==0)
{
m_info = NumericalIssue;
return;
}
// Take the 2-norm of the current row as a relative tolerance
rownorm = sqrt(rownorm);
// 3 - eliminate the previous nonzero rows
Index jj = 0;
Index len = 0;
while (jj < sizel)
{
// In order to eliminate in the correct order,
// we must select first the smallest column index among ju(jj:sizel)
Index k;
Index minrow = ju.segment(jj,sizel-jj).minCoeff(&k); // k is relative to the segment
k += jj;
if (minrow != ju(jj))
{
// swap the two locations
Index j = ju(jj);
swap(ju(jj), ju(k));
jr(minrow) = convert_index<StorageIndex>(jj);
jr(j) = convert_index<StorageIndex>(k);
swap(u(jj), u(k));
}
// Reset this location
jr(minrow) = -1;
// Start elimination
typename FactorType::InnerIterator ki_it(m_lu, minrow);
while (ki_it && ki_it.index() < minrow) ++ki_it;
eigen_internal_assert(ki_it && ki_it.col()==minrow);
Scalar fact = u(jj) / ki_it.value();
// drop too small elements
if(abs(fact) <= m_droptol)
{
jj++;
continue;
}
// linear combination of the current row ii and the row minrow
++ki_it;
for (; ki_it; ++ki_it)
{
Scalar prod = fact * ki_it.value();
Index j = ki_it.index();
Index jpos = jr(j);
if (jpos == -1) // fill-in element
{
Index newpos;
if (j >= ii) // dealing with the upper part
{
newpos = ii + sizeu;
sizeu++;
eigen_internal_assert(sizeu<=n);
}
else // dealing with the lower part
{
newpos = sizel;
sizel++;
eigen_internal_assert(sizel<=ii);
}
ju(newpos) = convert_index<StorageIndex>(j);
u(newpos) = -prod;
jr(j) = convert_index<StorageIndex>(newpos);
}
else
u(jpos) -= prod;
}
// store the pivot element
u(len) = fact;
ju(len) = convert_index<StorageIndex>(minrow);
++len;
jj++;
} // end of the elimination on the row ii
// reset the upper part of the pointer jr to zero
for(Index k = 0; k <sizeu; k++) jr(ju(ii+k)) = -1;
// 4 - partially sort and insert the elements in the m_lu matrix
// sort the L-part of the row
sizel = len;
len = (std::min)(sizel, nnzL);
typename Vector::SegmentReturnType ul(u.segment(0, sizel));
typename VectorI::SegmentReturnType jul(ju.segment(0, sizel));
internal::QuickSplit(ul, jul, len);
// store the largest m_fill elements of the L part
m_lu.startVec(ii);
for(Index k = 0; k < len; k++)
m_lu.insertBackByOuterInnerUnordered(ii,ju(k)) = u(k);
// store the diagonal element
// apply a shifting rule to avoid zero pivots (we are doing an incomplete factorization)
if (u(ii) == Scalar(0))
u(ii) = sqrt(m_droptol) * rownorm;
m_lu.insertBackByOuterInnerUnordered(ii, ii) = u(ii);
// sort the U-part of the row
// apply the dropping rule first
len = 0;
for(Index k = 1; k < sizeu; k++)
{
if(abs(u(ii+k)) > m_droptol * rownorm )
{
++len;
u(ii + len) = u(ii + k);
ju(ii + len) = ju(ii + k);
}
}
sizeu = len + 1; // +1 to take into account the diagonal element
len = (std::min)(sizeu, nnzU);
typename Vector::SegmentReturnType uu(u.segment(ii+1, sizeu-1));
typename VectorI::SegmentReturnType juu(ju.segment(ii+1, sizeu-1));
internal::QuickSplit(uu, juu, len);
// store the largest elements of the U part
for(Index k = ii + 1; k < ii + len; k++)
m_lu.insertBackByOuterInnerUnordered(ii,ju(k)) = u(k);
}
m_lu.finalize();
m_lu.makeCompressed();
m_factorizationIsOk = true;
m_info = Success;
}
} // end namespace Eigen
#endif // EIGEN_INCOMPLETE_LUT_H

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// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2011-2014 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_ITERATIVE_SOLVER_BASE_H
#define EIGEN_ITERATIVE_SOLVER_BASE_H
namespace Eigen {
namespace internal {
template<typename MatrixType>
struct is_ref_compatible_impl
{
private:
template <typename T0>
struct any_conversion
{
template <typename T> any_conversion(const volatile T&);
template <typename T> any_conversion(T&);
};
struct yes {int a[1];};
struct no {int a[2];};
template<typename T>
static yes test(const Ref<const T>&, int);
template<typename T>
static no test(any_conversion<T>, ...);
public:
static MatrixType ms_from;
enum { value = sizeof(test<MatrixType>(ms_from, 0))==sizeof(yes) };
};
template<typename MatrixType>
struct is_ref_compatible
{
enum { value = is_ref_compatible_impl<typename remove_all<MatrixType>::type>::value };
};
template<typename MatrixType, bool MatrixFree = !internal::is_ref_compatible<MatrixType>::value>
class generic_matrix_wrapper;
// We have an explicit matrix at hand, compatible with Ref<>
template<typename MatrixType>
class generic_matrix_wrapper<MatrixType,false>
{
public:
typedef Ref<const MatrixType> ActualMatrixType;
template<int UpLo> struct ConstSelfAdjointViewReturnType {
typedef typename ActualMatrixType::template ConstSelfAdjointViewReturnType<UpLo>::Type Type;
};
enum {
MatrixFree = false
};
generic_matrix_wrapper()
: m_dummy(0,0), m_matrix(m_dummy)
{}
template<typename InputType>
generic_matrix_wrapper(const InputType &mat)
: m_matrix(mat)
{}
const ActualMatrixType& matrix() const
{
return m_matrix;
}
template<typename MatrixDerived>
void grab(const EigenBase<MatrixDerived> &mat)
{
m_matrix.~Ref<const MatrixType>();
::new (&m_matrix) Ref<const MatrixType>(mat.derived());
}
void grab(const Ref<const MatrixType> &mat)
{
if(&(mat.derived()) != &m_matrix)
{
m_matrix.~Ref<const MatrixType>();
::new (&m_matrix) Ref<const MatrixType>(mat);
}
}
protected:
MatrixType m_dummy; // used to default initialize the Ref<> object
ActualMatrixType m_matrix;
};
// MatrixType is not compatible with Ref<> -> matrix-free wrapper
template<typename MatrixType>
class generic_matrix_wrapper<MatrixType,true>
{
public:
typedef MatrixType ActualMatrixType;
template<int UpLo> struct ConstSelfAdjointViewReturnType
{
typedef ActualMatrixType Type;
};
enum {
MatrixFree = true
};
generic_matrix_wrapper()
: mp_matrix(0)
{}
generic_matrix_wrapper(const MatrixType &mat)
: mp_matrix(&mat)
{}
const ActualMatrixType& matrix() const
{
return *mp_matrix;
}
void grab(const MatrixType &mat)
{
mp_matrix = &mat;
}
protected:
const ActualMatrixType *mp_matrix;
};
}
/** \ingroup IterativeLinearSolvers_Module
* \brief Base class for linear iterative solvers
*
* \sa class SimplicialCholesky, DiagonalPreconditioner, IdentityPreconditioner
*/
template< typename Derived>
class IterativeSolverBase : public SparseSolverBase<Derived>
{
protected:
typedef SparseSolverBase<Derived> Base;
using Base::m_isInitialized;
public:
typedef typename internal::traits<Derived>::MatrixType MatrixType;
typedef typename internal::traits<Derived>::Preconditioner Preconditioner;
typedef typename MatrixType::Scalar Scalar;
typedef typename MatrixType::StorageIndex StorageIndex;
typedef typename MatrixType::RealScalar RealScalar;
enum {
ColsAtCompileTime = MatrixType::ColsAtCompileTime,
MaxColsAtCompileTime = MatrixType::MaxColsAtCompileTime
};
public:
using Base::derived;
/** Default constructor. */
IterativeSolverBase()
{
init();
}
/** Initialize the solver with matrix \a A for further \c Ax=b solving.
*
* This constructor is a shortcut for the default constructor followed
* by a call to compute().
*
* \warning this class stores a reference to the matrix A as well as some
* precomputed values that depend on it. Therefore, if \a A is changed
* this class becomes invalid. Call compute() to update it with the new
* matrix A, or modify a copy of A.
*/
template<typename MatrixDerived>
explicit IterativeSolverBase(const EigenBase<MatrixDerived>& A)
: m_matrixWrapper(A.derived())
{
init();
compute(matrix());
}
~IterativeSolverBase() {}
/** Initializes the iterative solver for the sparsity pattern of the matrix \a A for further solving \c Ax=b problems.
*
* Currently, this function mostly calls analyzePattern on the preconditioner. In the future
* we might, for instance, implement column reordering for faster matrix vector products.
*/
template<typename MatrixDerived>
Derived& analyzePattern(const EigenBase<MatrixDerived>& A)
{
grab(A.derived());
m_preconditioner.analyzePattern(matrix());
m_isInitialized = true;
m_analysisIsOk = true;
m_info = m_preconditioner.info();
return derived();
}
/** Initializes the iterative solver with the numerical values of the matrix \a A for further solving \c Ax=b problems.
*
* Currently, this function mostly calls factorize on the preconditioner.
*
* \warning this class stores a reference to the matrix A as well as some
* precomputed values that depend on it. Therefore, if \a A is changed
* this class becomes invalid. Call compute() to update it with the new
* matrix A, or modify a copy of A.
*/
template<typename MatrixDerived>
Derived& factorize(const EigenBase<MatrixDerived>& A)
{
eigen_assert(m_analysisIsOk && "You must first call analyzePattern()");
grab(A.derived());
m_preconditioner.factorize(matrix());
m_factorizationIsOk = true;
m_info = m_preconditioner.info();
return derived();
}
/** Initializes the iterative solver with the matrix \a A for further solving \c Ax=b problems.
*
* Currently, this function mostly initializes/computes the preconditioner. In the future
* we might, for instance, implement column reordering for faster matrix vector products.
*
* \warning this class stores a reference to the matrix A as well as some
* precomputed values that depend on it. Therefore, if \a A is changed
* this class becomes invalid. Call compute() to update it with the new
* matrix A, or modify a copy of A.
*/
template<typename MatrixDerived>
Derived& compute(const EigenBase<MatrixDerived>& A)
{
grab(A.derived());
m_preconditioner.compute(matrix());
m_isInitialized = true;
m_analysisIsOk = true;
m_factorizationIsOk = true;
m_info = m_preconditioner.info();
return derived();
}
/** \internal */
Index rows() const { return matrix().rows(); }
/** \internal */
Index cols() const { return matrix().cols(); }
/** \returns the tolerance threshold used by the stopping criteria.
* \sa setTolerance()
*/
RealScalar tolerance() const { return m_tolerance; }
/** Sets the tolerance threshold used by the stopping criteria.
*
* This value is used as an upper bound to the relative residual error: |Ax-b|/|b|.
* The default value is the machine precision given by NumTraits<Scalar>::epsilon()
*/
Derived& setTolerance(const RealScalar& tolerance)
{
m_tolerance = tolerance;
return derived();
}
/** \returns a read-write reference to the preconditioner for custom configuration. */
Preconditioner& preconditioner() { return m_preconditioner; }
/** \returns a read-only reference to the preconditioner. */
const Preconditioner& preconditioner() const { return m_preconditioner; }
/** \returns the max number of iterations.
* It is either the value setted by setMaxIterations or, by default,
* twice the number of columns of the matrix.
*/
Index maxIterations() const
{
return (m_maxIterations<0) ? 2*matrix().cols() : m_maxIterations;
}
/** Sets the max number of iterations.
* Default is twice the number of columns of the matrix.
*/
Derived& setMaxIterations(Index maxIters)
{
m_maxIterations = maxIters;
return derived();
}
/** \returns the number of iterations performed during the last solve */
Index iterations() const
{
eigen_assert(m_isInitialized && "ConjugateGradient is not initialized.");
return m_iterations;
}
/** \returns the tolerance error reached during the last solve.
* It is a close approximation of the true relative residual error |Ax-b|/|b|.
*/
RealScalar error() const
{
eigen_assert(m_isInitialized && "ConjugateGradient is not initialized.");
return m_error;
}
/** \returns the solution x of \f$ A x = b \f$ using the current decomposition of A
* and \a x0 as an initial solution.
*
* \sa solve(), compute()
*/
template<typename Rhs,typename Guess>
inline const SolveWithGuess<Derived, Rhs, Guess>
solveWithGuess(const MatrixBase<Rhs>& b, const Guess& x0) 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 SolveWithGuess<Derived, Rhs, Guess>(derived(), b.derived(), x0);
}
/** \returns Success if the iterations converged, and NoConvergence otherwise. */
ComputationInfo info() const
{
eigen_assert(m_isInitialized && "IterativeSolverBase is not initialized.");
return m_info;
}
/** \internal */
template<typename Rhs, typename DestDerived>
void _solve_impl(const Rhs& b, SparseMatrixBase<DestDerived> &aDest) const
{
eigen_assert(rows()==b.rows());
Index rhsCols = b.cols();
Index size = b.rows();
DestDerived& dest(aDest.derived());
typedef typename DestDerived::Scalar DestScalar;
Eigen::Matrix<DestScalar,Dynamic,1> tb(size);
Eigen::Matrix<DestScalar,Dynamic,1> tx(cols());
// We do not directly fill dest because sparse expressions have to be free of aliasing issue.
// For non square least-square problems, b and dest might not have the same size whereas they might alias each-other.
typename DestDerived::PlainObject tmp(cols(),rhsCols);
for(Index k=0; k<rhsCols; ++k)
{
tb = b.col(k);
tx = derived().solve(tb);
tmp.col(k) = tx.sparseView(0);
}
dest.swap(tmp);
}
protected:
void init()
{
m_isInitialized = false;
m_analysisIsOk = false;
m_factorizationIsOk = false;
m_maxIterations = -1;
m_tolerance = NumTraits<Scalar>::epsilon();
}
typedef internal::generic_matrix_wrapper<MatrixType> MatrixWrapper;
typedef typename MatrixWrapper::ActualMatrixType ActualMatrixType;
const ActualMatrixType& matrix() const
{
return m_matrixWrapper.matrix();
}
template<typename InputType>
void grab(const InputType &A)
{
m_matrixWrapper.grab(A);
}
MatrixWrapper m_matrixWrapper;
Preconditioner m_preconditioner;
Index m_maxIterations;
RealScalar m_tolerance;
mutable RealScalar m_error;
mutable Index m_iterations;
mutable ComputationInfo m_info;
mutable bool m_analysisIsOk, m_factorizationIsOk;
};
} // end namespace Eigen
#endif // EIGEN_ITERATIVE_SOLVER_BASE_H

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// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2015 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_LEAST_SQUARE_CONJUGATE_GRADIENT_H
#define EIGEN_LEAST_SQUARE_CONJUGATE_GRADIENT_H
namespace Eigen {
namespace internal {
/** \internal Low-level conjugate gradient algorithm for least-square problems
* \param mat The matrix A
* \param rhs The right hand side vector b
* \param x On input and initial solution, on output the computed solution.
* \param precond A preconditioner being able to efficiently solve for an
* approximation of A'Ax=b (regardless of b)
* \param iters On input the max number of iteration, on output the number of performed iterations.
* \param tol_error On input the tolerance error, on output an estimation of the relative error.
*/
template<typename MatrixType, typename Rhs, typename Dest, typename Preconditioner>
EIGEN_DONT_INLINE
void least_square_conjugate_gradient(const MatrixType& mat, const Rhs& rhs, Dest& x,
const Preconditioner& precond, Index& iters,
typename Dest::RealScalar& tol_error)
{
using std::sqrt;
using std::abs;
typedef typename Dest::RealScalar RealScalar;
typedef typename Dest::Scalar Scalar;
typedef Matrix<Scalar,Dynamic,1> VectorType;
RealScalar tol = tol_error;
Index maxIters = iters;
Index m = mat.rows(), n = mat.cols();
VectorType residual = rhs - mat * x;
VectorType normal_residual = mat.adjoint() * residual;
RealScalar rhsNorm2 = (mat.adjoint()*rhs).squaredNorm();
if(rhsNorm2 == 0)
{
x.setZero();
iters = 0;
tol_error = 0;
return;
}
RealScalar threshold = tol*tol*rhsNorm2;
RealScalar residualNorm2 = normal_residual.squaredNorm();
if (residualNorm2 < threshold)
{
iters = 0;
tol_error = sqrt(residualNorm2 / rhsNorm2);
return;
}
VectorType p(n);
p = precond.solve(normal_residual); // initial search direction
VectorType z(n), tmp(m);
RealScalar absNew = numext::real(normal_residual.dot(p)); // the square of the absolute value of r scaled by invM
Index i = 0;
while(i < maxIters)
{
tmp.noalias() = mat * p;
Scalar alpha = absNew / tmp.squaredNorm(); // the amount we travel on dir
x += alpha * p; // update solution
residual -= alpha * tmp; // update residual
normal_residual = mat.adjoint() * residual; // update residual of the normal equation
residualNorm2 = normal_residual.squaredNorm();
if(residualNorm2 < threshold)
break;
z = precond.solve(normal_residual); // approximately solve for "A'A z = normal_residual"
RealScalar absOld = absNew;
absNew = numext::real(normal_residual.dot(z)); // update the absolute value of r
RealScalar beta = absNew / absOld; // calculate the Gram-Schmidt value used to create the new search direction
p = z + beta * p; // update search direction
i++;
}
tol_error = sqrt(residualNorm2 / rhsNorm2);
iters = i;
}
}
template< typename _MatrixType,
typename _Preconditioner = LeastSquareDiagonalPreconditioner<typename _MatrixType::Scalar> >
class LeastSquaresConjugateGradient;
namespace internal {
template< typename _MatrixType, typename _Preconditioner>
struct traits<LeastSquaresConjugateGradient<_MatrixType,_Preconditioner> >
{
typedef _MatrixType MatrixType;
typedef _Preconditioner Preconditioner;
};
}
/** \ingroup IterativeLinearSolvers_Module
* \brief A conjugate gradient solver for sparse (or dense) least-square problems
*
* This class allows to solve for A x = b linear problems using an iterative conjugate gradient algorithm.
* The matrix A can be non symmetric and rectangular, but the matrix A' A should be positive-definite to guaranty stability.
* Otherwise, the SparseLU or SparseQR classes might be preferable.
* The matrix A and the vectors x and b can be either dense or sparse.
*
* \tparam _MatrixType the type of the matrix A, can be a dense or a sparse matrix.
* \tparam _Preconditioner the type of the preconditioner. Default is LeastSquareDiagonalPreconditioner
*
* \implsparsesolverconcept
*
* The maximal number of iterations and tolerance value can be controlled via the setMaxIterations()
* and setTolerance() methods. The defaults are the size of the problem for the maximal number of iterations
* and NumTraits<Scalar>::epsilon() for the tolerance.
*
* This class can be used as the direct solver classes. Here is a typical usage example:
\code
int m=1000000, n = 10000;
VectorXd x(n), b(m);
SparseMatrix<double> A(m,n);
// fill A and b
LeastSquaresConjugateGradient<SparseMatrix<double> > lscg;
lscg.compute(A);
x = lscg.solve(b);
std::cout << "#iterations: " << lscg.iterations() << std::endl;
std::cout << "estimated error: " << lscg.error() << std::endl;
// update b, and solve again
x = lscg.solve(b);
\endcode
*
* By default the iterations start with x=0 as an initial guess of the solution.
* One can control the start using the solveWithGuess() method.
*
* \sa class ConjugateGradient, SparseLU, SparseQR
*/
template< typename _MatrixType, typename _Preconditioner>
class LeastSquaresConjugateGradient : public IterativeSolverBase<LeastSquaresConjugateGradient<_MatrixType,_Preconditioner> >
{
typedef IterativeSolverBase<LeastSquaresConjugateGradient> Base;
using Base::matrix;
using Base::m_error;
using Base::m_iterations;
using Base::m_info;
using Base::m_isInitialized;
public:
typedef _MatrixType MatrixType;
typedef typename MatrixType::Scalar Scalar;
typedef typename MatrixType::RealScalar RealScalar;
typedef _Preconditioner Preconditioner;
public:
/** Default constructor. */
LeastSquaresConjugateGradient() : Base() {}
/** Initialize the solver with matrix \a A for further \c Ax=b solving.
*
* This constructor is a shortcut for the default constructor followed
* by a call to compute().
*
* \warning this class stores a reference to the matrix A as well as some
* precomputed values that depend on it. Therefore, if \a A is changed
* this class becomes invalid. Call compute() to update it with the new
* matrix A, or modify a copy of A.
*/
template<typename MatrixDerived>
explicit LeastSquaresConjugateGradient(const EigenBase<MatrixDerived>& A) : Base(A.derived()) {}
~LeastSquaresConjugateGradient() {}
/** \internal */
template<typename Rhs,typename Dest>
void _solve_with_guess_impl(const Rhs& b, Dest& x) const
{
m_iterations = Base::maxIterations();
m_error = Base::m_tolerance;
for(Index j=0; j<b.cols(); ++j)
{
m_iterations = Base::maxIterations();
m_error = Base::m_tolerance;
typename Dest::ColXpr xj(x,j);
internal::least_square_conjugate_gradient(matrix(), b.col(j), xj, Base::m_preconditioner, m_iterations, m_error);
}
m_isInitialized = true;
m_info = m_error <= Base::m_tolerance ? Success : NoConvergence;
}
/** \internal */
using Base::_solve_impl;
template<typename Rhs,typename Dest>
void _solve_impl(const MatrixBase<Rhs>& b, Dest& x) const
{
x.setZero();
_solve_with_guess_impl(b.derived(),x);
}
};
} // end namespace Eigen
#endif // EIGEN_LEAST_SQUARE_CONJUGATE_GRADIENT_H

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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_SOLVEWITHGUESS_H
#define EIGEN_SOLVEWITHGUESS_H
namespace Eigen {
template<typename Decomposition, typename RhsType, typename GuessType> class SolveWithGuess;
/** \class SolveWithGuess
* \ingroup IterativeLinearSolvers_Module
*
* \brief Pseudo expression representing a solving operation
*
* \tparam Decomposition the type of the matrix or decomposion object
* \tparam Rhstype the type of the right-hand side
*
* This class represents an expression of A.solve(B)
* and most of the time this is the only way it is used.
*
*/
namespace internal {
template<typename Decomposition, typename RhsType, typename GuessType>
struct traits<SolveWithGuess<Decomposition, RhsType, GuessType> >
: traits<Solve<Decomposition,RhsType> >
{};
}
template<typename Decomposition, typename RhsType, typename GuessType>
class SolveWithGuess : public internal::generic_xpr_base<SolveWithGuess<Decomposition,RhsType,GuessType>, MatrixXpr, typename internal::traits<RhsType>::StorageKind>::type
{
public:
typedef typename internal::traits<SolveWithGuess>::Scalar Scalar;
typedef typename internal::traits<SolveWithGuess>::PlainObject PlainObject;
typedef typename internal::generic_xpr_base<SolveWithGuess<Decomposition,RhsType,GuessType>, MatrixXpr, typename internal::traits<RhsType>::StorageKind>::type Base;
typedef typename internal::ref_selector<SolveWithGuess>::type Nested;
SolveWithGuess(const Decomposition &dec, const RhsType &rhs, const GuessType &guess)
: m_dec(dec), m_rhs(rhs), m_guess(guess)
{}
EIGEN_DEVICE_FUNC Index rows() const { return m_dec.cols(); }
EIGEN_DEVICE_FUNC Index cols() const { return m_rhs.cols(); }
EIGEN_DEVICE_FUNC const Decomposition& dec() const { return m_dec; }
EIGEN_DEVICE_FUNC const RhsType& rhs() const { return m_rhs; }
EIGEN_DEVICE_FUNC const GuessType& guess() const { return m_guess; }
protected:
const Decomposition &m_dec;
const RhsType &m_rhs;
const GuessType &m_guess;
private:
Scalar coeff(Index row, Index col) const;
Scalar coeff(Index i) const;
};
namespace internal {
// Evaluator of SolveWithGuess -> eval into a temporary
template<typename Decomposition, typename RhsType, typename GuessType>
struct evaluator<SolveWithGuess<Decomposition,RhsType, GuessType> >
: public evaluator<typename SolveWithGuess<Decomposition,RhsType,GuessType>::PlainObject>
{
typedef SolveWithGuess<Decomposition,RhsType,GuessType> SolveType;
typedef typename SolveType::PlainObject PlainObject;
typedef evaluator<PlainObject> Base;
evaluator(const SolveType& solve)
: m_result(solve.rows(), solve.cols())
{
::new (static_cast<Base*>(this)) Base(m_result);
m_result = solve.guess();
solve.dec()._solve_with_guess_impl(solve.rhs(), m_result);
}
protected:
PlainObject m_result;
};
// Specialization for "dst = dec.solveWithGuess(rhs)"
// NOTE we need to specialize it for Dense2Dense to avoid ambiguous specialization error and a Sparse2Sparse specialization must exist somewhere
template<typename DstXprType, typename DecType, typename RhsType, typename GuessType, typename Scalar>
struct Assignment<DstXprType, SolveWithGuess<DecType,RhsType,GuessType>, internal::assign_op<Scalar,Scalar>, Dense2Dense>
{
typedef SolveWithGuess<DecType,RhsType,GuessType> SrcXprType;
static void run(DstXprType &dst, const SrcXprType &src, const internal::assign_op<Scalar,Scalar> &)
{
Index dstRows = src.rows();
Index dstCols = src.cols();
if((dst.rows()!=dstRows) || (dst.cols()!=dstCols))
dst.resize(dstRows, dstCols);
dst = src.guess();
src.dec()._solve_with_guess_impl(src.rhs(), dst/*, src.guess()*/);
}
};
} // end namepsace internal
} // end namespace Eigen
#endif // EIGEN_SOLVEWITHGUESS_H