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130 lines
3.7 KiB
C++
130 lines
3.7 KiB
C++
// This file is part of Eigen, a lightweight C++ template library
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// for linear algebra.
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//
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// Copyright (C) 2014 Gael Guennebaud <gael.guennebaud@inria.fr>
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//
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// This Source Code Form is subject to the terms of the Mozilla
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// Public License v. 2.0. If a copy of the MPL was not distributed
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// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
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#ifndef EIGEN_INVERSE_H
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#define EIGEN_INVERSE_H
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namespace Eigen {
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// TODO move the general declaration in Core, and rename this file DenseInverseImpl.h, or something like this...
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template<typename XprType,typename StorageKind> class InverseImpl;
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namespace internal {
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template<typename XprType>
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struct traits<Inverse<XprType> >
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: traits<typename XprType::PlainObject>
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{
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typedef typename XprType::PlainObject PlainObject;
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typedef traits<PlainObject> BaseTraits;
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enum {
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Flags = BaseTraits::Flags & RowMajorBit
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};
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};
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} // end namespace internal
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/** \class Inverse
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*
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* \brief Expression of the inverse of another expression
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*
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* \tparam XprType the type of the expression we are taking the inverse
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*
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* This class represents an abstract expression of A.inverse()
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* and most of the time this is the only way it is used.
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*
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*/
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template<typename XprType>
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class Inverse : public InverseImpl<XprType,typename internal::traits<XprType>::StorageKind>
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{
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public:
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typedef typename XprType::StorageIndex StorageIndex;
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typedef typename XprType::PlainObject PlainObject;
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typedef typename internal::nested<XprType>::type XprTypeNested;
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typedef typename internal::remove_all<XprTypeNested>::type XprTypeNestedCleaned;
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explicit Inverse(const XprType &xpr)
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: m_xpr(xpr)
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{}
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EIGEN_DEVICE_FUNC Index rows() const { return m_xpr.rows(); }
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EIGEN_DEVICE_FUNC Index cols() const { return m_xpr.cols(); }
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EIGEN_DEVICE_FUNC const XprTypeNestedCleaned& nestedExpression() const { return m_xpr; }
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protected:
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XprTypeNested m_xpr;
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};
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/** \internal
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* Specialization of the Inverse expression for dense expressions.
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* Direct access to the coefficients are discared.
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* FIXME this intermediate class is probably not needed anymore.
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*/
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template<typename XprType>
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class InverseImpl<XprType,Dense>
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: public MatrixBase<Inverse<XprType> >
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{
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typedef Inverse<XprType> Derived;
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public:
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typedef MatrixBase<Derived> Base;
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EIGEN_DENSE_PUBLIC_INTERFACE(Derived)
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typedef typename internal::remove_all<XprType>::type NestedExpression;
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private:
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Scalar coeff(Index row, Index col) const;
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Scalar coeff(Index i) const;
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};
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namespace internal {
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/** \internal
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* \brief Default evaluator for Inverse expression.
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*
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* This default evaluator for Inverse expression simply evaluate the inverse into a temporary
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* by a call to internal::call_assignment_no_alias.
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* Therefore, inverse implementers only have to specialize Assignment<Dst,Inverse<...>, ...> for
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* there own nested expression.
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*
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* \sa class Inverse
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*/
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template<typename ArgType>
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struct unary_evaluator<Inverse<ArgType> >
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: public evaluator<typename Inverse<ArgType>::PlainObject>::type
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{
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typedef Inverse<ArgType> InverseType;
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typedef typename InverseType::PlainObject PlainObject;
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typedef typename evaluator<PlainObject>::type Base;
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typedef evaluator<InverseType> type;
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typedef evaluator<InverseType> nestedType;
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enum { Flags = Base::Flags | EvalBeforeNestingBit };
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unary_evaluator(const InverseType& inv_xpr)
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: m_result(inv_xpr.rows(), inv_xpr.cols())
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{
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::new (static_cast<Base*>(this)) Base(m_result);
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internal::call_assignment_no_alias(m_result, inv_xpr);
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}
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protected:
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PlainObject m_result;
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};
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} // end namespace internal
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} // end namespace Eigen
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#endif // EIGEN_INVERSE_H
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