source: NonGTP/Boost/boost/numeric/interval/rounded_arith.hpp @ 857

Revision 857, 4.7 KB checked in by igarcia, 19 years ago (diff)
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1/* Boost interval/rounded_arith.hpp template implementation file
2 *
3 * Copyright 2002-2003 Hervé Brönnimann, Guillaume Melquiond, Sylvain Pion
4 *
5 * Distributed under the Boost Software License, Version 1.0.
6 * (See accompanying file LICENSE_1_0.txt or
7 * copy at http://www.boost.org/LICENSE_1_0.txt)
8 */
9
10#ifndef BOOST_NUMERIC_INTERVAL_ROUNDED_ARITH_HPP
11#define BOOST_NUMERIC_INTERVAL_ROUNDED_ARITH_HPP
12
13#include <boost/numeric/interval/rounding.hpp>
14#include <boost/numeric/interval/detail/bugs.hpp>
15#include <cmath>
16
17namespace boost {
18namespace numeric {
19namespace interval_lib {
20
21/*
22 * Three classes of rounding: exact, std, opp
23 * See documentation for details.
24 */
25
26template<class T, class Rounding>
27struct rounded_arith_exact: Rounding {
28  void init() { }
29  template<class U> T conv_down(U const &v) { return v; }
30  template<class U> T conv_up  (U const &v) { return v; }
31  T add_down (const T& x, const T& y) { return x + y; }
32  T add_up   (const T& x, const T& y) { return x + y; }
33  T sub_down (const T& x, const T& y) { return x - y; }
34  T sub_up   (const T& x, const T& y) { return x - y; }
35  T mul_down (const T& x, const T& y) { return x * y; }
36  T mul_up   (const T& x, const T& y) { return x * y; }
37  T div_down (const T& x, const T& y) { return x / y; }
38  T div_up   (const T& x, const T& y) { return x / y; }
39  T median   (const T& x, const T& y) { return (x + y) / 2; }
40  T sqrt_down(const T& x)
41  { BOOST_NUMERIC_INTERVAL_using_math(sqrt); return sqrt(x); }
42  T sqrt_up  (const T& x)
43  { BOOST_NUMERIC_INTERVAL_using_math(sqrt); return sqrt(x); }
44  T int_down (const T& x)
45  { BOOST_NUMERIC_INTERVAL_using_math(floor); return floor(x); }
46  T int_up   (const T& x)
47  { BOOST_NUMERIC_INTERVAL_using_math(ceil); return ceil(x); }
48};
49
50template<class T, class Rounding>
51struct rounded_arith_std: Rounding {
52# define BOOST_DN(EXPR) this->downward();   return this->force_rounding(EXPR)
53# define BOOST_NR(EXPR) this->to_nearest(); return this->force_rounding(EXPR)
54# define BOOST_UP(EXPR) this->upward();     return this->force_rounding(EXPR)
55  void init() { }
56  template<class U> T conv_down(U const &v) { BOOST_DN(v); }
57  template<class U> T conv_up  (U const &v) { BOOST_UP(v); }
58  T add_down(const T& x, const T& y) { BOOST_DN(x + y); }
59  T sub_down(const T& x, const T& y) { BOOST_DN(x - y); }
60  T mul_down(const T& x, const T& y) { BOOST_DN(x * y); }
61  T div_down(const T& x, const T& y) { BOOST_DN(x / y); }
62  T add_up  (const T& x, const T& y) { BOOST_UP(x + y); }
63  T sub_up  (const T& x, const T& y) { BOOST_UP(x - y); }
64  T mul_up  (const T& x, const T& y) { BOOST_UP(x * y); }
65  T div_up  (const T& x, const T& y) { BOOST_UP(x / y); }
66  T median(const T& x, const T& y) { BOOST_NR((x + y) / 2); }
67  T sqrt_down(const T& x)
68  { BOOST_NUMERIC_INTERVAL_using_math(sqrt); BOOST_DN(sqrt(x)); }
69  T sqrt_up  (const T& x)
70  { BOOST_NUMERIC_INTERVAL_using_math(sqrt); BOOST_UP(sqrt(x)); }
71  T int_down(const T& x) { this->downward(); return to_int(x); }
72  T int_up  (const T& x) { this->upward();   return to_int(x); }
73# undef BOOST_DN
74# undef BOOST_NR
75# undef BOOST_UP
76};
77 
78template<class T, class Rounding>
79struct rounded_arith_opp: Rounding {
80  void init() { this->upward(); }
81# define BOOST_DN(EXPR) \
82    this->downward(); \
83    T r = this->force_rounding(EXPR); \
84    this->upward(); \
85    return r
86# define BOOST_NR(EXPR) \
87    this->to_nearest(); \
88    T r = this->force_rounding(EXPR); \
89    this->upward(); \
90    return r
91# define BOOST_UP(EXPR) return this->force_rounding(EXPR)
92# define BOOST_UP_NEG(EXPR) return -this->force_rounding(EXPR)
93  template<class U> T conv_down(U const &v) { BOOST_UP_NEG(-v); }
94  template<class U> T conv_up  (U const &v) { BOOST_UP(v); }
95  T add_down(const T& x, const T& y) { BOOST_UP_NEG((-x) - y); }
96  T sub_down(const T& x, const T& y) { BOOST_UP_NEG(y - x); }
97  T mul_down(const T& x, const T& y) { BOOST_UP_NEG(x * (-y)); }
98  T div_down(const T& x, const T& y) { BOOST_UP_NEG(x / (-y)); }
99  T add_up  (const T& x, const T& y) { BOOST_UP(x + y); }
100  T sub_up  (const T& x, const T& y) { BOOST_UP(x - y); }
101  T mul_up  (const T& x, const T& y) { BOOST_UP(x * y); }
102  T div_up  (const T& x, const T& y) { BOOST_UP(x / y); }
103  T median  (const T& x, const T& y) { BOOST_NR((x + y) / 2); }
104  T sqrt_down(const T& x)
105  { BOOST_NUMERIC_INTERVAL_using_math(sqrt); BOOST_DN(sqrt(x)); }
106  T sqrt_up  (const T& x)
107  { BOOST_NUMERIC_INTERVAL_using_math(sqrt); BOOST_UP(sqrt(x)); }
108  T int_down(const T& x) { return -to_int(-x); }
109  T int_up  (const T& x) { return to_int(x); }
110# undef BOOST_DN
111# undef BOOST_NR
112# undef BOOST_UP
113# undef BOOST_UP_NEG
114};
115
116} // namespace interval_lib
117} // namespace numeric
118} // namespace boost
119
120#endif // BOOST_NUMERIC_INTERVAL_ROUNDED_ARITH_HPP
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