128 lines
4.4 KiB
C++
128 lines
4.4 KiB
C++
// This file is part of Eigen, a lightweight C++ template library
|
|
// for linear algebra.
|
|
//
|
|
// Copyright (C) 2008-2014 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_COREITERATORS_H
|
|
#define EIGEN_COREITERATORS_H
|
|
|
|
namespace Eigen {
|
|
|
|
/* This file contains the respective InnerIterator definition of the expressions defined in Eigen/Core
|
|
*/
|
|
|
|
namespace internal {
|
|
|
|
template<typename XprType, typename EvaluatorKind>
|
|
class inner_iterator_selector;
|
|
|
|
}
|
|
|
|
/** \class InnerIterator
|
|
* \brief An InnerIterator allows to loop over the element of any matrix expression.
|
|
*
|
|
* \warning To be used with care because an evaluator is constructed every time an InnerIterator iterator is constructed.
|
|
*
|
|
* TODO: add a usage example
|
|
*/
|
|
template<typename XprType>
|
|
class InnerIterator
|
|
{
|
|
protected:
|
|
typedef internal::inner_iterator_selector<XprType, typename internal::evaluator_traits<XprType>::Kind> IteratorType;
|
|
typedef internal::evaluator<XprType> EvaluatorType;
|
|
typedef typename internal::traits<XprType>::Scalar Scalar;
|
|
public:
|
|
/** Construct an iterator over the \a outerId -th row or column of \a xpr */
|
|
InnerIterator(const XprType &xpr, const Index &outerId)
|
|
: m_eval(xpr), m_iter(m_eval, outerId, xpr.innerSize())
|
|
{}
|
|
|
|
/// \returns the value of the current coefficient.
|
|
EIGEN_STRONG_INLINE Scalar value() const { return m_iter.value(); }
|
|
/** Increment the iterator \c *this to the next non-zero coefficient.
|
|
* Explicit zeros are not skipped over. To skip explicit zeros, see class SparseView
|
|
*/
|
|
EIGEN_STRONG_INLINE InnerIterator& operator++() { m_iter.operator++(); return *this; }
|
|
/// \returns the column or row index of the current coefficient.
|
|
EIGEN_STRONG_INLINE Index index() const { return m_iter.index(); }
|
|
/// \returns the row index of the current coefficient.
|
|
EIGEN_STRONG_INLINE Index row() const { return m_iter.row(); }
|
|
/// \returns the column index of the current coefficient.
|
|
EIGEN_STRONG_INLINE Index col() const { return m_iter.col(); }
|
|
/// \returns \c true if the iterator \c *this still references a valid coefficient.
|
|
EIGEN_STRONG_INLINE operator bool() const { return m_iter; }
|
|
|
|
protected:
|
|
EvaluatorType m_eval;
|
|
IteratorType m_iter;
|
|
private:
|
|
// If you get here, then you're not using the right InnerIterator type, e.g.:
|
|
// SparseMatrix<double,RowMajor> A;
|
|
// SparseMatrix<double>::InnerIterator it(A,0);
|
|
template<typename T> InnerIterator(const EigenBase<T>&,Index outer);
|
|
};
|
|
|
|
namespace internal {
|
|
|
|
// Generic inner iterator implementation for dense objects
|
|
template<typename XprType>
|
|
class inner_iterator_selector<XprType, IndexBased>
|
|
{
|
|
protected:
|
|
typedef evaluator<XprType> EvaluatorType;
|
|
typedef typename traits<XprType>::Scalar Scalar;
|
|
enum { IsRowMajor = (XprType::Flags&RowMajorBit)==RowMajorBit };
|
|
|
|
public:
|
|
EIGEN_STRONG_INLINE inner_iterator_selector(const EvaluatorType &eval, const Index &outerId, const Index &innerSize)
|
|
: m_eval(eval), m_inner(0), m_outer(outerId), m_end(innerSize)
|
|
{}
|
|
|
|
EIGEN_STRONG_INLINE Scalar value() const
|
|
{
|
|
return (IsRowMajor) ? m_eval.coeff(m_outer, m_inner)
|
|
: m_eval.coeff(m_inner, m_outer);
|
|
}
|
|
|
|
EIGEN_STRONG_INLINE inner_iterator_selector& operator++() { m_inner++; return *this; }
|
|
|
|
EIGEN_STRONG_INLINE Index index() const { return m_inner; }
|
|
inline Index row() const { return IsRowMajor ? m_outer : index(); }
|
|
inline Index col() const { return IsRowMajor ? index() : m_outer; }
|
|
|
|
EIGEN_STRONG_INLINE operator bool() const { return m_inner < m_end && m_inner>=0; }
|
|
|
|
protected:
|
|
const EvaluatorType& m_eval;
|
|
Index m_inner;
|
|
const Index m_outer;
|
|
const Index m_end;
|
|
};
|
|
|
|
// For iterator-based evaluator, inner-iterator is already implemented as
|
|
// evaluator<>::InnerIterator
|
|
template<typename XprType>
|
|
class inner_iterator_selector<XprType, IteratorBased>
|
|
: public evaluator<XprType>::InnerIterator
|
|
{
|
|
protected:
|
|
typedef typename evaluator<XprType>::InnerIterator Base;
|
|
typedef evaluator<XprType> EvaluatorType;
|
|
|
|
public:
|
|
EIGEN_STRONG_INLINE inner_iterator_selector(const EvaluatorType &eval, const Index &outerId, const Index &/*innerSize*/)
|
|
: Base(eval, outerId)
|
|
{}
|
|
};
|
|
|
|
} // end namespace internal
|
|
|
|
} // end namespace Eigen
|
|
|
|
#endif // EIGEN_COREITERATORS_H
|