diff options
Diffstat (limited to 'Eigen/src/SparseCore/SparseView.h')
| -rw-r--r-- | Eigen/src/SparseCore/SparseView.h | 200 |
1 files changed, 161 insertions, 39 deletions
diff --git a/Eigen/src/SparseCore/SparseView.h b/Eigen/src/SparseCore/SparseView.h index fd8450463..40a3019fa 100644 --- a/Eigen/src/SparseCore/SparseView.h +++ b/Eigen/src/SparseCore/SparseView.h @@ -1,7 +1,7 @@ // This file is part of Eigen, a lightweight C++ template library // for linear algebra. // -// Copyright (C) 2011 Gael Guennebaud <gael.guennebaud@inria.fr> +// Copyright (C) 2011-2014 Gael Guennebaud <gael.guennebaud@inria.fr> // Copyright (C) 2010 Daniel Lowengrub <lowdanie@gmail.com> // // This Source Code Form is subject to the terms of the Mozilla @@ -34,64 +34,186 @@ class SparseView : public SparseMatrixBase<SparseView<MatrixType> > typedef typename internal::remove_all<MatrixTypeNested>::type _MatrixTypeNested; public: EIGEN_SPARSE_PUBLIC_INTERFACE(SparseView) + typedef typename internal::remove_all<MatrixType>::type NestedExpression; - SparseView(const MatrixType& mat, const Scalar& m_reference = Scalar(0), - typename NumTraits<Scalar>::Real m_epsilon = NumTraits<Scalar>::dummy_precision()) : + explicit SparseView(const MatrixType& mat, const Scalar& m_reference = Scalar(0), + RealScalar m_epsilon = NumTraits<Scalar>::dummy_precision()) : m_matrix(mat), m_reference(m_reference), m_epsilon(m_epsilon) {} - class InnerIterator; - inline Index rows() const { return m_matrix.rows(); } inline Index cols() const { return m_matrix.cols(); } inline Index innerSize() const { return m_matrix.innerSize(); } inline Index outerSize() const { return m_matrix.outerSize(); } - + + /** \returns the nested expression */ + const typename internal::remove_all<MatrixTypeNested>::type& + nestedExpression() const { return m_matrix; } + + Scalar reference() const { return m_reference; } + RealScalar epsilon() const { return m_epsilon; } + protected: MatrixTypeNested m_matrix; Scalar m_reference; - typename NumTraits<Scalar>::Real m_epsilon; + RealScalar m_epsilon; }; -template<typename MatrixType> -class SparseView<MatrixType>::InnerIterator : public _MatrixTypeNested::InnerIterator -{ - typedef typename SparseView::Index Index; -public: - typedef typename _MatrixTypeNested::InnerIterator IterBase; - InnerIterator(const SparseView& view, Index outer) : - IterBase(view.m_matrix, outer), m_view(view) - { - incrementToNonZero(); - } - - EIGEN_STRONG_INLINE InnerIterator& operator++() - { - IterBase::operator++(); - incrementToNonZero(); - return *this; - } - - using IterBase::value; +namespace internal { -protected: - const SparseView& m_view; +// TODO find a way to unify the two following variants +// This is tricky because implementing an inner iterator on top of an IndexBased evaluator is +// not easy because the evaluators do not expose the sizes of the underlying expression. + +template<typename ArgType> +struct unary_evaluator<SparseView<ArgType>, IteratorBased> + : public evaluator_base<SparseView<ArgType> > +{ + typedef typename evaluator<ArgType>::InnerIterator EvalIterator; + public: + typedef SparseView<ArgType> XprType; + + class InnerIterator : public EvalIterator + { + typedef typename XprType::Scalar Scalar; + public: + + EIGEN_STRONG_INLINE InnerIterator(const unary_evaluator& sve, typename XprType::Index outer) + : EvalIterator(sve.m_argImpl,outer), m_view(sve.m_view) + { + incrementToNonZero(); + } + + EIGEN_STRONG_INLINE InnerIterator& operator++() + { + EvalIterator::operator++(); + incrementToNonZero(); + return *this; + } + + using EvalIterator::value; + + protected: + const XprType &m_view; + + private: + void incrementToNonZero() + { + while((bool(*this)) && internal::isMuchSmallerThan(value(), m_view.reference(), m_view.epsilon())) + { + EvalIterator::operator++(); + } + } + }; + + enum { + CoeffReadCost = evaluator<ArgType>::CoeffReadCost, + Flags = XprType::Flags + }; + + explicit unary_evaluator(const XprType& xpr) : m_argImpl(xpr.nestedExpression()), m_view(xpr) {} + + protected: + typename evaluator<ArgType>::nestedType m_argImpl; + const XprType &m_view; +}; -private: - void incrementToNonZero() - { - while((bool(*this)) && internal::isMuchSmallerThan(value(), m_view.m_reference, m_view.m_epsilon)) +template<typename ArgType> +struct unary_evaluator<SparseView<ArgType>, IndexBased> + : public evaluator_base<SparseView<ArgType> > +{ + public: + typedef SparseView<ArgType> XprType; + protected: + enum { IsRowMajor = (XprType::Flags&RowMajorBit)==RowMajorBit }; + typedef typename XprType::Index Index; + typedef typename XprType::Scalar Scalar; + public: + + class InnerIterator { - IterBase::operator++(); - } - } + public: + + EIGEN_STRONG_INLINE InnerIterator(const unary_evaluator& sve, typename XprType::Index outer) + : m_sve(sve), m_inner(0), m_outer(outer), m_end(sve.m_view.innerSize()) + { + incrementToNonZero(); + } + + EIGEN_STRONG_INLINE InnerIterator& operator++() + { + m_inner++; + incrementToNonZero(); + return *this; + } + + EIGEN_STRONG_INLINE Scalar value() const + { + return (IsRowMajor) ? m_sve.m_argImpl.coeff(m_outer, m_inner) + : m_sve.m_argImpl.coeff(m_inner, m_outer); + } + + 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 unary_evaluator &m_sve; + Index m_inner; + const Index m_outer; + const Index m_end; + + private: + void incrementToNonZero() + { + while((bool(*this)) && internal::isMuchSmallerThan(value(), m_sve.m_view.reference(), m_sve.m_view.epsilon())) + { + m_inner++; + } + } + }; + + enum { + CoeffReadCost = evaluator<ArgType>::CoeffReadCost, + Flags = XprType::Flags + }; + + explicit unary_evaluator(const XprType& xpr) : m_argImpl(xpr.nestedExpression()), m_view(xpr) {} + + protected: + typename evaluator<ArgType>::nestedType m_argImpl; + const XprType &m_view; }; +} // end namespace internal + +template<typename Derived> +const SparseView<Derived> MatrixBase<Derived>::sparseView(const Scalar& reference, + const typename NumTraits<Scalar>::Real& epsilon) const +{ + return SparseView<Derived>(derived(), reference, epsilon); +} + +/** \returns an expression of \c *this with values smaller than + * \a reference * \a epsilon are removed. + * + * This method is typically used in conjunction with the product of two sparse matrices + * to automatically prune the smallest values as follows: + * \code + * C = (A*B).pruned(); // suppress numerical zeros (exact) + * C = (A*B).pruned(ref); + * C = (A*B).pruned(ref,epsilon); + * \endcode + * where \c ref is a meaningful non zero reference value. + * */ template<typename Derived> -const SparseView<Derived> MatrixBase<Derived>::sparseView(const Scalar& m_reference, - const typename NumTraits<Scalar>::Real& m_epsilon) const +const SparseView<Derived> +SparseMatrixBase<Derived>::pruned(const Scalar& reference, + const RealScalar& epsilon) const { - return SparseView<Derived>(derived(), m_reference, m_epsilon); + return SparseView<Derived>(derived(), reference, epsilon); } } // end namespace Eigen |