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dekker.one
1/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
2/*
3 * Main authors:
4 * Vincent Barichard <Vincent.Barichard@univ-angers.fr>
5 *
6 * Copyright:
7 * Vincent Barichard, 2012
8 *
9 * This file is part of Gecode, the generic constraint
10 * development environment:
11 * http://www.gecode.org
12 *
13 * Permission is hereby granted, free of charge, to any person obtaining
14 * a copy of this software and associated documentation files (the
15 * "Software"), to deal in the Software without restriction, including
16 * without limitation the rights to use, copy, modify, merge, publish,
17 * distribute, sublicense, and/or sell copies of the Software, and to
18 * permit persons to whom the Software is furnished to do so, subject to
19 * the following conditions:
20 *
21 * The above copyright notice and this permission notice shall be
22 * included in all copies or substantial portions of the Software.
23 *
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
28 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
29 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
30 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
31 *
32 */
33
34namespace Gecode { namespace Float { namespace Arithmetic {
35
36
37 /*
38 * Bounds consistent square operator
39 *
40 */
41
42 template<class A, class B>
43 forceinline
44 Pow<A,B>::Pow(Home home, A x0, B x1, int n)
45 : MixBinaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND>(home,x0,x1), m_n(n) {}
46
47 template<class A, class B>
48 ExecStatus
49 Pow<A,B>::post(Home home, A x0, B x1, int n) {
50 if (n == 0) {
51 if ((x0.min() == 0.0) && (x0.max() == 0.0)) return ES_FAILED;
52 GECODE_ME_CHECK(x1.eq(home,1.0));
53 return ES_OK;
54 }
55
56 GECODE_ME_CHECK(x1.eq(home,pow(x0.domain(),n)));
57 if ((x1.min() == 0.0) && (x1.max() == 0.0)) {
58 GECODE_ME_CHECK(x1.eq(home,0.0));
59 return ES_OK;
60 }
61
62 if ((n % 2) == 0) {
63 if (x0.min() >= 0)
64 GECODE_ME_CHECK(x0.eq(home,nroot(x1.domain(),n)));
65 else if (x0.max() <= 0)
66 GECODE_ME_CHECK(x0.eq(home,-nroot(x1.domain(),n)));
67 else
68 GECODE_ME_CHECK(x0.eq(home,
69 hull(
70 nroot(x1.domain(),n),
71 -nroot(x1.domain(),n)
72 )
73 ));
74 } else {
75 GECODE_ME_CHECK(x0.eq(home,nroot(x1.domain(),n)));
76 }
77
78 if (!x0.assigned()) (void) new (home) Pow<A,B>(home,x0,x1,n);
79 return ES_OK;
80 }
81
82 template<class A, class B>
83 forceinline
84 Pow<A,B>::Pow(Space& home, Pow<A,B>& p)
85 : MixBinaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND>(home,p), m_n(p.m_n) {}
86
87 template<class A, class B>
88 Actor*
89 Pow<A,B>::copy(Space& home) {
90 return new (home) Pow<A,B>(home,*this);
91 }
92
93 template<class A, class B>
94 ExecStatus
95 Pow<A,B>::propagate(Space& home, const ModEventDelta&) {
96 if ((x0.min() == 0.0) && (x0.max() == 0.0)) return ES_FAILED;
97 GECODE_ME_CHECK(x1.eq(home,pow(x0.domain(),m_n)));
98
99 if ((x1.min() == 0.0) && (x1.max() == 0.0)) {
100 GECODE_ME_CHECK(x1.eq(home,0.0));
101 return home.ES_SUBSUMED(*this);
102 }
103
104 if ((m_n % 2) == 0) {
105 if (x0.min() >= 0)
106 GECODE_ME_CHECK(x0.eq(home,nroot(x1.domain(),m_n)));
107 else if (x0.max() <= 0)
108 GECODE_ME_CHECK(x0.eq(home,-nroot(x1.domain(),m_n)));
109 else
110 GECODE_ME_CHECK(x0.eq(home,
111 hull(
112 nroot(x1.domain(),m_n),
113 -nroot(x1.domain(),m_n)
114 )
115 ));
116 } else {
117 GECODE_ME_CHECK(x0.eq(home,nroot(x1.domain(),m_n)));
118 }
119 return x0.assigned() ? home.ES_SUBSUMED(*this) : ES_FIX;
120 }
121
122 /*
123 * Bounds consistent square root operator
124 *
125 */
126
127 template<class A, class B>
128 forceinline
129 NthRoot<A,B>::NthRoot(Home home, A x0, B x1, int n)
130 : MixBinaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND>(home,x0,x1), m_n(n) {}
131
132 template<class A, class B>
133 ExecStatus
134 NthRoot<A,B>::post(Home home, A x0, B x1, int n) {
135 if (n == 0) return ES_FAILED;
136 GECODE_ME_CHECK(x0.gq(home,0.0));
137 GECODE_ME_CHECK(x1.eq(home,nroot(x0.domain(),n)));
138 GECODE_ME_CHECK(x0.eq(home,pow(x1.domain(),n)));
139 (void) new (home) NthRoot<A,B>(home,x0,x1,n);
140 return ES_OK;
141 }
142
143 template<class A, class B>
144 forceinline
145 NthRoot<A,B>::NthRoot(Space& home, NthRoot<A,B>& p)
146 : MixBinaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND>(home,p), m_n(p.m_n) {}
147
148 template<class A, class B>
149 Actor*
150 NthRoot<A,B>::copy(Space& home) {
151 return new (home) NthRoot<A,B>(home,*this);
152 }
153
154 template<class A, class B>
155 ExecStatus
156 NthRoot<A,B>::propagate(Space& home, const ModEventDelta&) {
157 GECODE_ME_CHECK(x1.eq(home,nroot(x0.domain(),m_n)));
158 GECODE_ME_CHECK(x0.eq(home,pow(x1.domain(),m_n)));
159 return x0.assigned() ? home.ES_SUBSUMED(*this) : ES_FIX;
160 }
161
162
163}}}
164
165// STATISTICS: float-prop
166