// 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
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
