gtsam/gtsam/3rdparty/Spectra/MatOp/internal/SymGEigsRegInvOp.h

73 lines
2.0 KiB
C++

// Copyright (C) 2017-2019 Yixuan Qiu <yixuan.qiu@cos.name>
//
// 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 https://mozilla.org/MPL/2.0/.
#ifndef SYM_GEIGS_REG_INV_OP_H
#define SYM_GEIGS_REG_INV_OP_H
#include <Eigen/Core>
#include "../SparseSymMatProd.h"
#include "../SparseRegularInverse.h"
namespace Spectra {
///
/// \ingroup Operators
///
/// This class defines the matrix operation for generalized eigen solver in the
/// regular inverse mode. This class is intended for internal use.
///
template <typename Scalar = double,
typename OpType = SparseSymMatProd<double>,
typename BOpType = SparseRegularInverse<double> >
class SymGEigsRegInvOp
{
private:
typedef Eigen::Index Index;
typedef Eigen::Matrix<Scalar, Eigen::Dynamic, Eigen::Dynamic> Matrix;
typedef Eigen::Matrix<Scalar, Eigen::Dynamic, 1> Vector;
OpType& m_op;
BOpType& m_Bop;
Vector m_cache; // temporary working space
public:
///
/// Constructor to create the matrix operation object.
///
/// \param op Pointer to the \f$A\f$ matrix operation object.
/// \param Bop Pointer to the \f$B\f$ matrix operation object.
///
SymGEigsRegInvOp(OpType& op, BOpType& Bop) :
m_op(op), m_Bop(Bop), m_cache(op.rows())
{}
///
/// Return the number of rows of the underlying matrix.
///
Index rows() const { return m_Bop.rows(); }
///
/// Return the number of columns of the underlying matrix.
///
Index cols() const { return m_Bop.rows(); }
///
/// Perform the matrix operation \f$y=B^{-1}Ax\f$.
///
/// \param x_in Pointer to the \f$x\f$ vector.
/// \param y_out Pointer to the \f$y\f$ vector.
///
// y_out = inv(B) * A * x_in
void perform_op(const Scalar* x_in, Scalar* y_out)
{
m_op.perform_op(x_in, m_cache.data());
m_Bop.solve(m_cache.data(), y_out);
}
};
} // namespace Spectra
#endif // SYM_GEIGS_REG_INV_OP_H