mirror/eigen
2
0
Fork 0
mirror of https://gitlab.com/libeigen/eigen.git synced 2025-02-11 18:00:51 +08:00
Code Issues Packages Projects Releases Wiki Activity

fix fuzzy compares for integer types, using a selector

Browse Source
This commit is contained in:
Benoit Jacob 2011-02-07 10:53:17 -05:00
parent c5c8efa575
commit 68a2e04a96
1 changed files with 64 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
Eigen/src/Core/Fuzzy.h
View File

@ -26,7 +26,67 @@
#ifndef EIGEN_FUZZY_H
#define EIGEN_FUZZY_H
// TODO support small integer types properly i.e. do exact compare on coeffs --- taking a HS norm is guaranteed to cause integer overflow.
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)
{
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 * std::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.
@ -52,12 +112,7 @@ bool DenseBase<Derived>::isApprox(
RealScalar prec
) const
{
const typename internal::nested<Derived,2>::type nested(derived());
const typename internal::nested<OtherDerived,2>::type otherNested(other.derived());
// std::cerr << typeid(Derived).name() << " => " << typeid(typename internal::nested<Derived,2>::type).name() << "\n";
// std::cerr << typeid(OtherDerived).name() << " => " << typeid(typename internal::nested<OtherDerived,2>::type).name() << "\n";
// return false;
return (nested - otherNested).cwiseAbs2().sum() <= prec * prec * std::min(nested.cwiseAbs2().sum(), otherNested.cwiseAbs2().sum());
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,
@ -79,7 +134,7 @@ bool DenseBase<Derived>::isMuchSmallerThan(
RealScalar prec
) const
{
return derived().cwiseAbs2().sum() <= prec * prec * other * other;
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,
@ -99,7 +154,7 @@ bool DenseBase<Derived>::isMuchSmallerThan(
RealScalar prec
) const
{
return derived().cwiseAbs2().sum() <= prec * prec * other.derived().cwiseAbs2().sum();
return internal::isMuchSmallerThan_object_selector<Derived, OtherDerived>::run(derived(), other.derived(), prec);
}
#endif // EIGEN_FUZZY_H