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author | 2007-12-28 16:00:55 +0000 | |
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committer | 2007-12-28 16:00:55 +0000 | |
commit | dfdad129a3c6d5437eb001f5fe6d37de3fc07238 (patch) | |
tree | afbde1562e62b3952c8ce7a6b9c3cdd95fdb69c0 /Eigen/src/Core/Dot.h | |
parent | e7bdbe2e6a7d3d3e3f498e1ba9159b0ec1a8ccae (diff) |
move Core/ to a src/ subdir, in preparation for following changes
Diffstat (limited to 'Eigen/src/Core/Dot.h')
-rw-r--r-- | Eigen/src/Core/Dot.h | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/Eigen/src/Core/Dot.h b/Eigen/src/Core/Dot.h new file mode 100644 index 000000000..ae64a634a --- /dev/null +++ b/Eigen/src/Core/Dot.h @@ -0,0 +1,126 @@ +// This file is part of Eigen, a lightweight C++ template library +// for linear algebra. Eigen itself is part of the KDE project. +// +// Copyright (C) 2006-2007 Benoit Jacob <jacob@math.jussieu.fr> +// +// Eigen is free software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the Free Software +// Foundation; either version 2 or (at your option) any later version. +// +// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY +// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS +// FOR A PARTICULAR PURPOSE. See the GNU General Public License for more +// details. +// +// You should have received a copy of the GNU General Public License along +// with Eigen; if not, write to the Free Software Foundation, Inc., 51 +// Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. +// +// As a special exception, if other files instantiate templates or use macros +// or functions from this file, or you compile this file and link it +// with other works to produce a work based on this file, this file does not +// by itself cause the resulting work to be covered by the GNU General Public +// License. This exception does not invalidate any other reasons why a work +// based on this file might be covered by the GNU General Public License. + +#ifndef EIGEN_DOT_H +#define EIGEN_DOT_H + +template<int Index, int Size, typename Derived1, typename Derived2> +struct DotUnroller +{ + static void run(const Derived1 &v1, const Derived2& v2, typename Derived1::Scalar &dot) + { + DotUnroller<Index-1, Size, Derived1, Derived2>::run(v1, v2, dot); + dot += v1.coeff(Index) * conj(v2.coeff(Index)); + } +}; + +template<int Size, typename Derived1, typename Derived2> +struct DotUnroller<0, Size, Derived1, Derived2> +{ + static void run(const Derived1 &v1, const Derived2& v2, typename Derived1::Scalar &dot) + { + dot = v1.coeff(0) * conj(v2.coeff(0)); + } +}; + +template<int Index, typename Derived1, typename Derived2> +struct DotUnroller<Index, Dynamic, Derived1, Derived2> +{ + static void run(const Derived1&, const Derived2&, typename Derived1::Scalar&) {} +}; + +// prevent buggy user code from causing an infinite recursion +template<int Index, typename Derived1, typename Derived2> +struct DotUnroller<Index, 0, Derived1, Derived2> +{ + static void run(const Derived1&, const Derived2&, typename Derived1::Scalar&) {} +}; + +/** \returns the dot product of *this with other. + * + * \only_for_vectors + * + * \note If the scalar type is complex numbers, then this function returns the hermitian + * (sesquilinear) dot product, linear in the first variable and anti-linear in the + * second variable. + * + * \sa norm2(), norm() + */ +template<typename Scalar, typename Derived> +template<typename OtherDerived> +Scalar MatrixBase<Scalar, Derived>::dot(const OtherDerived& other) const +{ + assert(IsVectorAtCompileTime && OtherDerived::IsVectorAtCompileTime && size() == other.size()); + Scalar res; + if(EIGEN_UNROLLED_LOOPS && SizeAtCompileTime != Dynamic && SizeAtCompileTime <= 16) + DotUnroller<SizeAtCompileTime-1, SizeAtCompileTime, Derived, OtherDerived> + ::run(*static_cast<const Derived*>(this), other, res); + else + { + res = (*this).coeff(0) * conj(other.coeff(0)); + for(int i = 1; i < size(); i++) + res += (*this).coeff(i)* conj(other.coeff(i)); + } + return res; +} + +/** \returns the squared norm of *this, i.e. the dot product of *this with itself. + * + * \only_for_vectors + * + * \sa dot(), norm() + */ +template<typename Scalar, typename Derived> +typename NumTraits<Scalar>::Real MatrixBase<Scalar, Derived>::norm2() const +{ + return real(dot(*this)); +} + +/** \returns the norm of *this, i.e. the square root of the dot product of *this with itself. + * + * \only_for_vectors + * + * \sa dot(), norm2() + */ +template<typename Scalar, typename Derived> +typename NumTraits<Scalar>::Real MatrixBase<Scalar, Derived>::norm() const +{ + return sqrt(norm2()); +} + +/** \returns an expression of the quotient of *this by its own norm. + * + * \only_for_vectors + * + * \sa norm() + */ +template<typename Scalar, typename Derived> +const ScalarMultiple<typename NumTraits<Scalar>::Real, Derived> +MatrixBase<Scalar, Derived>::normalized() const +{ + return (*this) / norm(); +} + +#endif // EIGEN_DOT_H |