/src/Geometry_Eigen/Eigen/src/Core/Fuzzy.h
http://github.com/Akranar/daguerreo · C Header · 161 lines · 83 code · 14 blank · 64 comment · 3 complexity · 26f7a314741ac28ac604a3a5c28040c3 MD5 · raw file
- // This file is part of Eigen, a lightweight C++ template library
- // for linear algebra.
- //
- // Copyright (C) 2006-2008 Benoit Jacob <jacob.benoit.1@gmail.com>
- // Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
- //
- // Eigen is free software; you can redistribute it and/or
- // modify it under the terms of the GNU Lesser General Public
- // License as published by the Free Software Foundation; either
- // version 3 of the License, or (at your option) any later version.
- //
- // Alternatively, 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 of
- // the License, 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 Lesser General Public License or the
- // GNU General Public License for more details.
- //
- // You should have received a copy of the GNU Lesser General Public
- // License and a copy of the GNU General Public License along with
- // Eigen. If not, see <http://www.gnu.org/licenses/>.
- #ifndef EIGEN_FUZZY_H
- #define EIGEN_FUZZY_H
- namespace internal
- {
- template<typename Derived, typename OtherDerived, bool is_integer = NumTraits<typename Derived::Scalar>::IsInteger>
- struct isApprox_selector
- {
- static bool run(const Derived& x, const OtherDerived& y, typename Derived::RealScalar prec)
- {
- using std::min;
- const typename internal::nested<Derived,2>::type nested(x);
- const typename internal::nested<OtherDerived,2>::type otherNested(y);
- return (nested - otherNested).cwiseAbs2().sum() <= prec * prec * (min)(nested.cwiseAbs2().sum(), otherNested.cwiseAbs2().sum());
- }
- };
- template<typename Derived, typename OtherDerived>
- struct isApprox_selector<Derived, OtherDerived, true>
- {
- static bool run(const Derived& x, const OtherDerived& y, typename Derived::RealScalar)
- {
- return x.matrix() == y.matrix();
- }
- };
- template<typename Derived, typename OtherDerived, bool is_integer = NumTraits<typename Derived::Scalar>::IsInteger>
- struct isMuchSmallerThan_object_selector
- {
- static bool run(const Derived& x, const OtherDerived& y, typename Derived::RealScalar prec)
- {
- return x.cwiseAbs2().sum() <= abs2(prec) * y.cwiseAbs2().sum();
- }
- };
- template<typename Derived, typename OtherDerived>
- struct isMuchSmallerThan_object_selector<Derived, OtherDerived, true>
- {
- static bool run(const Derived& x, const OtherDerived&, typename Derived::RealScalar)
- {
- return x.matrix() == Derived::Zero(x.rows(), x.cols()).matrix();
- }
- };
- template<typename Derived, bool is_integer = NumTraits<typename Derived::Scalar>::IsInteger>
- struct isMuchSmallerThan_scalar_selector
- {
- static bool run(const Derived& x, const typename Derived::RealScalar& y, typename Derived::RealScalar prec)
- {
- return x.cwiseAbs2().sum() <= abs2(prec * y);
- }
- };
- template<typename Derived>
- struct isMuchSmallerThan_scalar_selector<Derived, true>
- {
- static bool run(const Derived& x, const typename Derived::RealScalar&, typename Derived::RealScalar)
- {
- return x.matrix() == Derived::Zero(x.rows(), x.cols()).matrix();
- }
- };
- } // end namespace internal
- /** \returns \c true if \c *this is approximately equal to \a other, within the precision
- * determined by \a prec.
- *
- * \note The fuzzy compares are done multiplicatively. Two vectors \f$ v \f$ and \f$ w \f$
- * are considered to be approximately equal within precision \f$ p \f$ if
- * \f[ \Vert v - w \Vert \leqslant p\,\(min)(\Vert v\Vert, \Vert w\Vert). \f]
- * For matrices, the comparison is done using the Hilbert-Schmidt norm (aka Frobenius norm
- * L2 norm).
- *
- * \note Because of the multiplicativeness of this comparison, one can't use this function
- * to check whether \c *this is approximately equal to the zero matrix or vector.
- * Indeed, \c isApprox(zero) returns false unless \c *this itself is exactly the zero matrix
- * or vector. If you want to test whether \c *this is zero, use internal::isMuchSmallerThan(const
- * RealScalar&, RealScalar) instead.
- *
- * \sa internal::isMuchSmallerThan(const RealScalar&, RealScalar) const
- */
- template<typename Derived>
- template<typename OtherDerived>
- bool DenseBase<Derived>::isApprox(
- const DenseBase<OtherDerived>& other,
- RealScalar prec
- ) const
- {
- return internal::isApprox_selector<Derived, OtherDerived>::run(derived(), other.derived(), prec);
- }
- /** \returns \c true if the norm of \c *this is much smaller than \a other,
- * within the precision determined by \a prec.
- *
- * \note The fuzzy compares are done multiplicatively. A vector \f$ v \f$ is
- * considered to be much smaller than \f$ x \f$ within precision \f$ p \f$ if
- * \f[ \Vert v \Vert \leqslant p\,\vert x\vert. \f]
- *
- * For matrices, the comparison is done using the Hilbert-Schmidt norm. For this reason,
- * the value of the reference scalar \a other should come from the Hilbert-Schmidt norm
- * of a reference matrix of same dimensions.
- *
- * \sa isApprox(), isMuchSmallerThan(const DenseBase<OtherDerived>&, RealScalar) const
- */
- template<typename Derived>
- bool DenseBase<Derived>::isMuchSmallerThan(
- const typename NumTraits<Scalar>::Real& other,
- RealScalar prec
- ) const
- {
- return internal::isMuchSmallerThan_scalar_selector<Derived>::run(derived(), other, prec);
- }
- /** \returns \c true if the norm of \c *this is much smaller than the norm of \a other,
- * within the precision determined by \a prec.
- *
- * \note The fuzzy compares are done multiplicatively. A vector \f$ v \f$ is
- * considered to be much smaller than a vector \f$ w \f$ within precision \f$ p \f$ if
- * \f[ \Vert v \Vert \leqslant p\,\Vert w\Vert. \f]
- * For matrices, the comparison is done using the Hilbert-Schmidt norm.
- *
- * \sa isApprox(), isMuchSmallerThan(const RealScalar&, RealScalar) const
- */
- template<typename Derived>
- template<typename OtherDerived>
- bool DenseBase<Derived>::isMuchSmallerThan(
- const DenseBase<OtherDerived>& other,
- RealScalar prec
- ) const
- {
- return internal::isMuchSmallerThan_object_selector<Derived, OtherDerived>::run(derived(), other.derived(), prec);
- }
- #endif // EIGEN_FUZZY_H