1 | /* Boost interval/detail/division.hpp file
|
---|
2 | *
|
---|
3 | * Copyright 2003 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_DETAIL_DIVISION_HPP
|
---|
11 | #define BOOST_NUMERIC_INTERVAL_DETAIL_DIVISION_HPP
|
---|
12 |
|
---|
13 | #include <boost/numeric/interval/detail/interval_prototype.hpp>
|
---|
14 | #include <boost/numeric/interval/detail/bugs.hpp>
|
---|
15 | #include <boost/numeric/interval/detail/test_input.hpp>
|
---|
16 | #include <boost/numeric/interval/rounded_arith.hpp>
|
---|
17 | #include <algorithm>
|
---|
18 |
|
---|
19 | namespace boost {
|
---|
20 | namespace numeric {
|
---|
21 | namespace interval_lib {
|
---|
22 | namespace detail {
|
---|
23 |
|
---|
24 | template<class T, class Policies> inline
|
---|
25 | interval<T, Policies> div_non_zero(const interval<T, Policies>& x,
|
---|
26 | const interval<T, Policies>& y)
|
---|
27 | {
|
---|
28 | // assert(!in_zero(y));
|
---|
29 | typename Policies::rounding rnd;
|
---|
30 | typedef interval<T, Policies> I;
|
---|
31 | const T& xl = x.lower();
|
---|
32 | const T& xu = x.upper();
|
---|
33 | const T& yl = y.lower();
|
---|
34 | const T& yu = y.upper();
|
---|
35 | if (::boost::numeric::interval_lib::user::is_neg(xu))
|
---|
36 | if (::boost::numeric::interval_lib::user::is_neg(yu))
|
---|
37 | return I(rnd.div_down(xu, yl), rnd.div_up(xl, yu), true);
|
---|
38 | else
|
---|
39 | return I(rnd.div_down(xl, yl), rnd.div_up(xu, yu), true);
|
---|
40 | else if (::boost::numeric::interval_lib::user::is_neg(xl))
|
---|
41 | if (::boost::numeric::interval_lib::user::is_neg(yu))
|
---|
42 | return I(rnd.div_down(xu, yu), rnd.div_up(xl, yu), true);
|
---|
43 | else
|
---|
44 | return I(rnd.div_down(xl, yl), rnd.div_up(xu, yl), true);
|
---|
45 | else
|
---|
46 | if (::boost::numeric::interval_lib::user::is_neg(yu))
|
---|
47 | return I(rnd.div_down(xu, yu), rnd.div_up(xl, yl), true);
|
---|
48 | else
|
---|
49 | return I(rnd.div_down(xl, yu), rnd.div_up(xu, yl), true);
|
---|
50 | }
|
---|
51 |
|
---|
52 | template<class T, class Policies> inline
|
---|
53 | interval<T, Policies> div_non_zero(const T& x, const interval<T, Policies>& y)
|
---|
54 | {
|
---|
55 | // assert(!in_zero(y));
|
---|
56 | typename Policies::rounding rnd;
|
---|
57 | typedef interval<T, Policies> I;
|
---|
58 | const T& yl = y.lower();
|
---|
59 | const T& yu = y.upper();
|
---|
60 | if (::boost::numeric::interval_lib::user::is_neg(x))
|
---|
61 | return I(rnd.div_down(x, yl), rnd.div_up(x, yu), true);
|
---|
62 | else
|
---|
63 | return I(rnd.div_down(x, yu), rnd.div_up(x, yl), true);
|
---|
64 | }
|
---|
65 |
|
---|
66 | template<class T, class Policies> inline
|
---|
67 | interval<T, Policies> div_positive(const interval<T, Policies>& x, const T& yu)
|
---|
68 | {
|
---|
69 | // assert(::boost::numeric::interval_lib::user::is_pos(yu));
|
---|
70 | if (::boost::numeric::interval_lib::user::is_zero(x.lower()) &&
|
---|
71 | ::boost::numeric::interval_lib::user::is_zero(x.upper()))
|
---|
72 | return x;
|
---|
73 | typename Policies::rounding rnd;
|
---|
74 | typedef interval<T, Policies> I;
|
---|
75 | const T& xl = x.lower();
|
---|
76 | const T& xu = x.upper();
|
---|
77 | typedef typename Policies::checking checking;
|
---|
78 | if (::boost::numeric::interval_lib::user::is_neg(xu))
|
---|
79 | return I(checking::neg_inf(), rnd.div_up(xu, yu), true);
|
---|
80 | else if (::boost::numeric::interval_lib::user::is_neg(xl))
|
---|
81 | return I(checking::neg_inf(), checking::pos_inf(), true);
|
---|
82 | else
|
---|
83 | return I(rnd.div_down(xl, yu), checking::pos_inf(), true);
|
---|
84 | }
|
---|
85 |
|
---|
86 | template<class T, class Policies> inline
|
---|
87 | interval<T, Policies> div_positive(const T& x, const T& yu)
|
---|
88 | {
|
---|
89 | // assert(::boost::numeric::interval_lib::user::is_pos(yu));
|
---|
90 | typedef interval<T, Policies> I;
|
---|
91 | if (::boost::numeric::interval_lib::user::is_zero(x))
|
---|
92 | return I(static_cast<T>(0), static_cast<T>(0), true);
|
---|
93 | typename Policies::rounding rnd;
|
---|
94 | typedef typename Policies::checking checking;
|
---|
95 | if (::boost::numeric::interval_lib::user::is_neg(x))
|
---|
96 | return I(checking::neg_inf(), rnd.div_up(x, yu), true);
|
---|
97 | else
|
---|
98 | return I(rnd.div_down(x, yu), checking::pos_inf(), true);
|
---|
99 | }
|
---|
100 |
|
---|
101 | template<class T, class Policies> inline
|
---|
102 | interval<T, Policies> div_negative(const interval<T, Policies>& x, const T& yl)
|
---|
103 | {
|
---|
104 | // assert(::boost::numeric::interval_lib::user::is_neg(yl));
|
---|
105 | if (::boost::numeric::interval_lib::user::is_zero(x.lower()) &&
|
---|
106 | ::boost::numeric::interval_lib::user::is_zero(x.upper()))
|
---|
107 | return x;
|
---|
108 | typename Policies::rounding rnd;
|
---|
109 | typedef interval<T, Policies> I;
|
---|
110 | const T& xl = x.lower();
|
---|
111 | const T& xu = x.upper();
|
---|
112 | typedef typename Policies::checking checking;
|
---|
113 | if (::boost::numeric::interval_lib::user::is_neg(xu))
|
---|
114 | return I(rnd.div_down(xu, yl), checking::pos_inf(), true);
|
---|
115 | else if (::boost::numeric::interval_lib::user::is_neg(xl))
|
---|
116 | return I(checking::neg_inf(), checking::pos_inf(), true);
|
---|
117 | else
|
---|
118 | return I(checking::neg_inf(), rnd.div_up(xl, yl), true);
|
---|
119 | }
|
---|
120 |
|
---|
121 | template<class T, class Policies> inline
|
---|
122 | interval<T, Policies> div_negative(const T& x, const T& yl)
|
---|
123 | {
|
---|
124 | // assert(::boost::numeric::interval_lib::user::is_neg(yl));
|
---|
125 | typedef interval<T, Policies> I;
|
---|
126 | if (::boost::numeric::interval_lib::user::is_zero(x))
|
---|
127 | return I(static_cast<T>(0), static_cast<T>(0), true);
|
---|
128 | typename Policies::rounding rnd;
|
---|
129 | typedef typename Policies::checking checking;
|
---|
130 | if (::boost::numeric::interval_lib::user::is_neg(x))
|
---|
131 | return I(rnd.div_down(x, yl), checking::pos_inf(), true);
|
---|
132 | else
|
---|
133 | return I(checking::neg_inf(), rnd.div_up(x, yl), true);
|
---|
134 | }
|
---|
135 |
|
---|
136 | template<class T, class Policies> inline
|
---|
137 | interval<T, Policies> div_zero(const interval<T, Policies>& x)
|
---|
138 | {
|
---|
139 | if (::boost::numeric::interval_lib::user::is_zero(x.lower()) &&
|
---|
140 | ::boost::numeric::interval_lib::user::is_zero(x.upper()))
|
---|
141 | return x;
|
---|
142 | else return interval<T, Policies>::whole();
|
---|
143 | }
|
---|
144 |
|
---|
145 | template<class T, class Policies> inline
|
---|
146 | interval<T, Policies> div_zero(const T& x)
|
---|
147 | {
|
---|
148 | if (::boost::numeric::interval_lib::user::is_zero(x))
|
---|
149 | return interval<T, Policies>(static_cast<T>(0), static_cast<T>(0), true);
|
---|
150 | else return interval<T, Policies>::whole();
|
---|
151 | }
|
---|
152 |
|
---|
153 | template<class T, class Policies> inline
|
---|
154 | interval<T, Policies> div_zero_part1(const interval<T, Policies>& x,
|
---|
155 | const interval<T, Policies>& y, bool& b)
|
---|
156 | {
|
---|
157 | // assert(::boost::numeric::interval_lib::user::is_neg(y.lower()) && ::boost::numeric::interval_lib::user::is_pos(y.upper()));
|
---|
158 | if (::boost::numeric::interval_lib::user::is_zero(x.lower()) && ::boost::numeric::interval_lib::user::is_zero(x.upper()))
|
---|
159 | { b = false; return x; }
|
---|
160 | typename Policies::rounding rnd;
|
---|
161 | typedef interval<T, Policies> I;
|
---|
162 | const T& xl = x.lower();
|
---|
163 | const T& xu = x.upper();
|
---|
164 | const T& yl = y.lower();
|
---|
165 | const T& yu = y.upper();
|
---|
166 | typedef typename Policies::checking checking;
|
---|
167 | if (::boost::numeric::interval_lib::user::is_neg(xu))
|
---|
168 | { b = true; return I(checking::neg_inf(), rnd.div_up(xu, yu), true); }
|
---|
169 | else if (::boost::numeric::interval_lib::user::is_neg(xl))
|
---|
170 | { b = false; return I(checking::neg_inf(), checking::pos_inf(), true); }
|
---|
171 | else
|
---|
172 | { b = true; return I(checking::neg_inf(), rnd.div_up(xl, yl), true); }
|
---|
173 | }
|
---|
174 |
|
---|
175 | template<class T, class Policies> inline
|
---|
176 | interval<T, Policies> div_zero_part2(const interval<T, Policies>& x,
|
---|
177 | const interval<T, Policies>& y)
|
---|
178 | {
|
---|
179 | // assert(::boost::numeric::interval_lib::user::is_neg(y.lower()) && ::boost::numeric::interval_lib::user::is_pos(y.upper()) && (div_zero_part1(x, y, b), b));
|
---|
180 | typename Policies::rounding rnd;
|
---|
181 | typedef interval<T, Policies> I;
|
---|
182 | typedef typename Policies::checking checking;
|
---|
183 | if (::boost::numeric::interval_lib::user::is_neg(x.upper()))
|
---|
184 | return I(rnd.div_down(x.upper(), y.lower()), checking::pos_inf(), true);
|
---|
185 | else
|
---|
186 | return I(rnd.div_down(x.lower(), y.upper()), checking::pos_inf(), true);
|
---|
187 | }
|
---|
188 |
|
---|
189 | } // namespace detail
|
---|
190 | } // namespace interval_lib
|
---|
191 | } // namespace numeric
|
---|
192 | } // namespace boost
|
---|
193 |
|
---|
194 | #endif // BOOST_NUMERIC_INTERVAL_DETAIL_DIVISION_HPP
|
---|