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// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2009 Benoit Jacob <jacob.benoit.1@gmail.com>
//
// 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_MISC_KERNEL_H
#define EIGEN_MISC_KERNEL_H
#include "./InternalHeaderCheck.h"
namespace Eigen {
namespace internal {
/** \class kernel_retval_base
*
*/
template<typename DecompositionType>
struct traits<kernel_retval_base<DecompositionType> >
{
typedef typename DecompositionType::MatrixType MatrixType;
typedef Matrix<
typename MatrixType::Scalar,
MatrixType::ColsAtCompileTime, // the number of rows in the "kernel matrix"
// is the number of cols of the original matrix
// so that the product "matrix * kernel = zero" makes sense
Dynamic, // we don't know at compile-time the dimension of the kernel
MatrixType::Options,
MatrixType::MaxColsAtCompileTime, // see explanation for 2nd template parameter
MatrixType::MaxColsAtCompileTime // the kernel is a subspace of the domain space,
// whose dimension is the number of columns of the original matrix
> ReturnType;
};
template<typename DecompositionType_> struct kernel_retval_base
: public ReturnByValue<kernel_retval_base<DecompositionType_> >
{
typedef DecompositionType_ DecompositionType;
typedef ReturnByValue<kernel_retval_base> Base;
explicit kernel_retval_base(const DecompositionType& dec)
: m_dec(dec),
m_rank(dec.rank()),
m_cols(m_rank==dec.cols() ? 1 : dec.cols() - m_rank)
{}
inline Index rows() const { return m_dec.cols(); }
inline Index cols() const { return m_cols; }
inline Index rank() const { return m_rank; }
inline const DecompositionType& dec() const { return m_dec; }
template<typename Dest> inline void evalTo(Dest& dst) const
{
static_cast<const kernel_retval<DecompositionType>*>(this)->evalTo(dst);
}
protected:
const DecompositionType& m_dec;
Index m_rank, m_cols;
};
} // end namespace internal
#define EIGEN_MAKE_KERNEL_HELPERS(DecompositionType) \
typedef typename DecompositionType::MatrixType MatrixType; \
typedef typename MatrixType::Scalar Scalar; \
typedef typename MatrixType::RealScalar RealScalar; \
typedef Eigen::internal::kernel_retval_base<DecompositionType> Base; \
using Base::dec; \
using Base::rank; \
using Base::rows; \
using Base::cols; \
kernel_retval(const DecompositionType& dec) : Base(dec) {}
} // end namespace Eigen
#endif // EIGEN_MISC_KERNEL_H