boost/numeric/interval/utility.hpp
/* Boost interval/utility.hpp template implementation file
*
* Copyright Jens Maurer 2000
* Copyright Herv� Br�nnimann, Guillaume Melquiond, Sylvain Pion 2002-2003
* Permission to use, copy, modify, sell, and distribute this software
* is hereby granted without fee provided that the above copyright notice
* appears in all copies and that both that copyright notice and this
* permission notice appear in supporting documentation,
*
* None of the above authors nor Polytechnic University make any
* representation about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
* $Id: utility.hpp,v 1.7 2003/09/12 06:06:12 gmelquio Exp $
*/
#ifndef BOOST_NUMERIC_INTERVAL_UTILITY_HPP
#define BOOST_NUMERIC_INTERVAL_UTILITY_HPP
#include <boost/numeric/interval/detail/interval_prototype.hpp>
#include <boost/numeric/interval/detail/test_input.hpp>
#include <boost/numeric/interval/detail/bugs.hpp>
#include <algorithm>
#include <utility>
/*
* Implementation of simple functions
*/
namespace boost {
namespace numeric {
/*
* Utility Functions
*/
template<class T, class Policies> inline
const T& lower(const interval<T, Policies>& x)
{
return x.lower();
}
template<class T, class Policies> inline
const T& upper(const interval<T, Policies>& x)
{
return x.upper();
}
template<class T, class Policies> inline
T checked_lower(const interval<T, Policies>& x)
{
if (empty(x)) {
typedef typename Policies::checking checking;
return checking::nan();
}
return x.lower();
}
template<class T, class Policies> inline
T checked_upper(const interval<T, Policies>& x)
{
if (empty(x)) {
typedef typename Policies::checking checking;
return checking::nan();
}
return x.upper();
}
template<class T, class Policies> inline
T width(const interval<T, Policies>& x)
{
if (interval_lib::detail::test_input(x)) return static_cast<T>(0);
typename Policies::rounding rnd;
return rnd.sub_up(x.upper(), x.lower());
}
template<class T, class Policies> inline
T median(const interval<T, Policies>& x)
{
if (interval_lib::detail::test_input(x)) {
typedef typename Policies::checking checking;
return checking::nan();
}
typename Policies::rounding rnd;
return rnd.median(x.lower(), x.upper());
}
template<class T, class Policies> inline
interval<T, Policies> widen(const interval<T, Policies>& x, const T& v)
{
if (interval_lib::detail::test_input(x))
return interval<T, Policies>::empty();
typename Policies::rounding rnd;
return interval<T, Policies>(rnd.sub_down(x.lower(), v),
rnd.add_up (x.upper(), v), true);
}
/*
* Set-like operations
*/
template<class T, class Policies> inline
bool empty(const interval<T, Policies>& x)
{
return interval_lib::detail::test_input(x);
}
template<class T, class Policies> inline
bool in_zero(const interval<T, Policies>& x)
{
if (interval_lib::detail::test_input(x)) return false;
return x.lower() <= static_cast<T>(0) && static_cast<T>(0) <= x.upper();
}
template<class T, class Policies> inline
bool in(const T& x, const interval<T, Policies>& y)
{
if (interval_lib::detail::test_input(x, y)) return false;
return y.lower() <= x && x <= y.upper();
}
template<class T, class Policies> inline
bool subset(const interval<T, Policies>& x,
const interval<T, Policies>& y)
{
if (empty(x)) return true;
return !empty(y) && y.lower() <= x.lower() && x.upper() <= y.upper();
}
template<class T, class Policies1, class Policies2> inline
bool proper_subset(const interval<T, Policies1>& x,
const interval<T, Policies2>& y)
{
if (empty(y)) return false;
if (empty(x)) return true;
return y.lower() <= x.lower() && x.upper() <= y.upper() &&
(y.lower() != x.lower() || x.upper() != y.upper());
}
template<class T, class Policies1, class Policies2> inline
bool overlap(const interval<T, Policies1>& x,
const interval<T, Policies2>& y)
{
if (interval_lib::detail::test_input(x, y)) return false;
return x.lower() <= y.lower() && y.lower() <= x.upper() ||
y.lower() <= x.lower() && x.lower() <= y.upper();
}
template<class T, class Policies> inline
bool singleton(const interval<T, Policies>& x)
{
return !empty(x) && x.lower() == x.upper();
}
template<class T, class Policies1, class Policies2> inline
bool equal(const interval<T, Policies1>& x, const interval<T, Policies2>& y)
{
if (empty(x)) return empty(y);
return !empty(y) && x.lower() == y.lower() && x.upper() == y.upper();
}
template<class T, class Policies> inline
interval<T, Policies> intersect(const interval<T, Policies>& x,
const interval<T, Policies>& y)
{
BOOST_NUMERIC_INTERVAL_using_max(min);
BOOST_NUMERIC_INTERVAL_using_max(max);
if (interval_lib::detail::test_input(x, y))
return interval<T, Policies>::empty();
const T& l = max(x.lower(), y.lower());
const T& u = min(x.upper(), y.upper());
if (l <= u) return interval<T, Policies>(l, u, true);
else return interval<T, Policies>::empty();
}
template<class T, class Policies> inline
interval<T, Policies> hull(const interval<T, Policies>& x,
const interval<T, Policies>& y)
{
BOOST_NUMERIC_INTERVAL_using_max(min);
BOOST_NUMERIC_INTERVAL_using_max(max);
bool bad_x = interval_lib::detail::test_input(x);
bool bad_y = interval_lib::detail::test_input(y);
if (bad_x)
if (bad_y) return interval<T, Policies>::empty();
else return y;
else
if (bad_y) return x;
return interval<T, Policies>(min(x.lower(), y.lower()),
max(x.upper(), y.upper()), true);
}
template<class T, class Policies> inline
interval<T, Policies> hull(const interval<T, Policies>& x, const T& y)
{
BOOST_NUMERIC_INTERVAL_using_max(min);
BOOST_NUMERIC_INTERVAL_using_max(max);
bool bad_x = interval_lib::detail::test_input(x);
bool bad_y = interval_lib::detail::test_input<T, Policies>(y);
if (bad_y)
if (bad_x) return interval<T, Policies>::empty();
else return x;
else
if (bad_x) return interval<T, Policies>(y, y, true);
return interval<T, Policies>(min(x.lower(), y),
max(x.upper(), y), true);
}
template<class T, class Policies> inline
interval<T, Policies> hull(const T& x, const interval<T, Policies>& y)
{
BOOST_NUMERIC_INTERVAL_using_max(min);
BOOST_NUMERIC_INTERVAL_using_max(max);
bool bad_x = interval_lib::detail::test_input<T, Policies>(x);
bool bad_y = interval_lib::detail::test_input(y);
if (bad_x)
if (bad_y) return interval<T, Policies>::empty();
else return y;
else
if (bad_y) return interval<T, Policies>(x, x, true);
return interval<T, Policies>(min(x, y.lower()),
max(x, y.upper()), true);
}
template<class T> inline
interval<T> hull(const T& x, const T& y)
{
return interval<T>::hull(x, y);
}
template<class T, class Policies> inline
std::pair<interval<T, Policies>, interval<T, Policies> >
bisect(const interval<T, Policies>& x)
{
typedef interval<T, Policies> I;
if (interval_lib::detail::test_input(x))
return std::pair<I,I>(I::empty(), I::empty());
const T m = median(x);
return std::pair<I,I>(I(x.lower(), m, true), I(m, x.upper(), true));
}
/*
* Elementary functions
*/
template<class T, class Policies> inline
T norm(const interval<T, Policies>& x)
{
BOOST_NUMERIC_INTERVAL_using_max(max);
typedef interval<T, Policies> I;
if (interval_lib::detail::test_input(x)) {
typedef typename Policies::checking checking;
return checking::nan();
}
return max(-x.lower(), x.upper());
}
template<class T, class Policies> inline
interval<T, Policies> abs(const interval<T, Policies>& x)
{
BOOST_NUMERIC_INTERVAL_using_max(max);
typedef interval<T, Policies> I;
if (interval_lib::detail::test_input(x))
return I::empty();
if (!interval_lib::detail::is_neg(x.lower())) return x;
if (interval_lib::detail::is_neg(x.upper())) return -x;
return I(static_cast<T>(0), max(-x.lower(), x.upper()), true);
}
template<class T, class Policies> inline
interval<T, Policies> max(const interval<T, Policies>& x,
const interval<T, Policies>& y)
{
BOOST_NUMERIC_INTERVAL_using_max(max);
typedef interval<T, Policies> I;
if (interval_lib::detail::test_input(x, y))
return I::empty();
return I(max(x.lower(), y.lower()), max(x.upper(), y.upper()), true);
}
template<class T, class Policies> inline
interval<T, Policies> max(const interval<T, Policies>& x, const T& y)
{
BOOST_NUMERIC_INTERVAL_using_max(max);
typedef interval<T, Policies> I;
if (interval_lib::detail::test_input(x, y))
return I::empty();
return I(max(x.lower(), y), max(x.upper(), y), true);
}
template<class T, class Policies> inline
interval<T, Policies> max(const T& x, const interval<T, Policies>& y)
{
BOOST_NUMERIC_INTERVAL_using_max(max);
typedef interval<T, Policies> I;
if (interval_lib::detail::test_input(x, y))
return I::empty();
return I(max(x, y.lower()), max(x, y.upper()), true);
}
template<class T, class Policies> inline
interval<T, Policies> min(const interval<T, Policies>& x,
const interval<T, Policies>& y)
{
BOOST_NUMERIC_INTERVAL_using_max(min);
typedef interval<T, Policies> I;
if (interval_lib::detail::test_input(x, y))
return I::empty();
return I(min(x.lower(), y.lower()), min(x.upper(), y.upper()), true);
}
template<class T, class Policies> inline
interval<T, Policies> min(const interval<T, Policies>& x, const T& y)
{
BOOST_NUMERIC_INTERVAL_using_max(min);
typedef interval<T, Policies> I;
if (interval_lib::detail::test_input(x, y))
return I::empty();
return I(min(x.lower(), y), min(x.upper(), y), true);
}
template<class T, class Policies> inline
interval<T, Policies> min(const T& x, const interval<T, Policies>& y)
{
BOOST_NUMERIC_INTERVAL_using_max(min);
typedef interval<T, Policies> I;
if (interval_lib::detail::test_input(x, y))
return I::empty();
return I(min(x, y.lower()), min(x, y.upper()), true);
}
} // namespace numeric
} // namespace boost
#endif // BOOST_NUMERIC_INTERVAL_UTILITY_HPP