Generated on Fri Oct 19 11:24:57 2018 for Gecode by doxygen 1.6.3

tanatan.hpp

Go to the documentation of this file.
00001 /* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
00002 /*
00003  *  Main authors:
00004  *     Vincent Barichard <Vincent.Barichard@univ-angers.fr>
00005  *
00006  *  Copyright:
00007  *     Vincent Barichard, 2012
00008  *
00009  *  This file is part of Gecode, the generic constraint
00010  *  development environment:
00011  *     http://www.gecode.org
00012  *
00013  *  Permission is hereby granted, free of charge, to any person obtaining
00014  *  a copy of this software and associated documentation files (the
00015  *  "Software"), to deal in the Software without restriction, including
00016  *  without limitation the rights to use, copy, modify, merge, publish,
00017  *  distribute, sublicense, and/or sell copies of the Software, and to
00018  *  permit persons to whom the Software is furnished to do so, subject to
00019  *  the following conditions:
00020  *
00021  *  The above copyright notice and this permission notice shall be
00022  *  included in all copies or substantial portions of the Software.
00023  *
00024  *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
00025  *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
00026  *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00027  *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
00028  *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
00029  *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
00030  *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00031  *
00032  */
00033 
00034 namespace Gecode { namespace Float { namespace Trigonometric {
00035   /*
00036    * ATan projection function
00037    *
00038    */
00039   template<class V>
00040   void
00041   aTanProject(Rounding& r, const V& aTanIv, FloatNum& iv_min, FloatNum& iv_max, int& n_min, int& n_max) {
00042     #define I0__PI_2I    FloatVal(0,pi_half_upper())
00043     #define POS(X) ((I0__PI_2I.in(X))?0:1)
00044     #define ATANINF_DOWN r.atan_down(aTanIv.min())
00045     #define ATANSUP_UP   r.atan_up(aTanIv.max())
00046 
00047     // 0 <=> in [0;PI/2]
00048     // 1 <=> in [PI/2;PI]
00049     switch ( POS(iv_min) )
00050     {
00051       case 0:
00052         if (r.tan_down(iv_min) > aTanIv.max())    { n_min++; iv_min = ATANINF_DOWN; }
00053         else if (r.tan_up(iv_min) < aTanIv.min()) {          iv_min = ATANINF_DOWN; }
00054         break;
00055       case 1:
00056         if (r.tan_down(iv_min) > aTanIv.max())    { n_min+=2; iv_min = ATANINF_DOWN; }
00057         else if (r.tan_up(iv_min) < aTanIv.min()) { n_min++;  iv_min = ATANINF_DOWN; }
00058         break;
00059       default:
00060         GECODE_NEVER;
00061         break;
00062     }
00063 
00064     // 0 <=> in [0;PI/2]
00065     // 1 <=> in [PI/2;PI]
00066     switch ( POS(iv_max) )
00067     {
00068       case 0:
00069         if (r.tan_down(iv_max) > aTanIv.max())    {          iv_max = ATANSUP_UP; }
00070         else if (r.tan_up(iv_max) < aTanIv.min()) { n_max--; iv_max = ATANSUP_UP; }
00071         break;
00072       case 1:
00073         if (r.tan_down(iv_max) > aTanIv.max())    { n_max++; iv_max = ATANSUP_UP; }
00074         else if (r.tan_up(iv_max) < aTanIv.min()) {          iv_max = ATANSUP_UP; }
00075         break;
00076       default:
00077         GECODE_NEVER;
00078         break;
00079     }
00080     #undef ATANINF_DOWN
00081     #undef ATANSUP_UP
00082     #undef POS
00083     #undef I0__PI_2I
00084   }
00085 
00086   /*
00087    * Bounds consistent tangent operator
00088    *
00089    */
00090 
00091   template<class A, class B>
00092   ExecStatus
00093   Tan<A,B>::dopropagate(Space& home, A x0, B x1) {
00094     Rounding r;
00095     int n_min = static_cast<int>(r.div_up(x0.min() + pi_half_upper(), pi_upper()));
00096     int n_max = static_cast<int>(r.div_up(x0.max() + pi_half_upper(), pi_upper()));
00097 
00098     if (x0 == x1) {
00099       #define I0__PI_2I    FloatVal(0,pi_half_upper())
00100       if (I0__PI_2I.in(x0.max()))  GECODE_ME_CHECK(x0.lq(home,0));
00101       if (I0__PI_2I.in(-x0.min())) GECODE_ME_CHECK(x0.gq(home,0));
00102       #undef I0__PI_2I
00103 
00104       n_min = static_cast<int>(r.div_up(x0.min(), pi_upper()));
00105       n_max = static_cast<int>(r.div_up(x0.max(), pi_upper()));
00106 
00107       FloatNum x0_min;
00108       FloatNum x0_max;
00109       FloatNum t = x0.min();
00110       do {
00111         x0_min = t;
00112         if (r.tan_down(x0_min) > x0_min) n_min++;
00113         t = r.add_down(r.mul_up(n_min,pi_upper()),r.tan_down(x0_min));
00114       } while (t > x0_min);
00115       t = r.sub_down(r.mul_up(2*n_max,pi_upper()),x0.max());
00116       do {
00117         x0_max = t;
00118         if (r.tan_down(x0_max) < x0_max) n_max--;
00119         t = r.add_up(r.mul_up(n_max,pi_upper()),r.tan_up(x0_max));
00120       } while (t > x0_max);
00121       x0_max = r.sub_up(r.mul_up(2*n_max,pi_upper()),x0_max);
00122 
00123       if (x0_min > x0_max) return ES_FAILED;
00124       GECODE_ME_CHECK(x0.eq(home,FloatVal(x0_min,x0_max)));
00125     } else {
00126       GECODE_ME_CHECK(x1.eq(home,tan(x0.val())));
00127       n_min = static_cast<int>(r.div_up(x0.min(), pi_upper()));
00128       n_max = static_cast<int>(r.div_up(x0.max(), pi_upper()));
00129       if (x0.min() < 0) n_min--;
00130       if (x0.max() < 0) n_max--;
00131       FloatNum iv_min = r.sub_down(x0.min(),r.mul_down(n_min, pi_upper()));
00132       FloatNum iv_max = r.sub_up  (x0.max(),r.mul_down(n_max, pi_upper()));
00133       aTanProject(r,x1,iv_min,iv_max,n_min,n_max);
00134       FloatNum n_iv_min = r.add_down(iv_min,r.mul_down(n_min, pi_upper()));
00135       FloatNum n_iv_max = r.add_up  (iv_max,r.mul_down(n_max, pi_upper()));
00136       if (n_iv_min > n_iv_max) return ES_FAILED;
00137       GECODE_ME_CHECK(x0.eq(home,FloatVal(n_iv_min,n_iv_max)));
00138       GECODE_ME_CHECK(x1.eq(home,tan(x0.val()))); // Redo tan because with x0 reduction, sin may be more accurate
00139     }
00140 
00141     return ES_OK;
00142   }
00143 
00144   template<class A, class B>
00145   forceinline
00146   Tan<A,B>::Tan(Home home, A x0, B x1)
00147     : MixBinaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND>(home,x0,x1) {}
00148 
00149   template<class A, class B>
00150   ExecStatus
00151   Tan<A,B>::post(Home home, A x0, B x1) {
00152     if (x0 == x1) {
00153       #define I0__PI_2I    FloatVal(0,pi_half_upper())
00154       if (I0__PI_2I.in(x0.max()))  GECODE_ME_CHECK(x0.lq(home,0));
00155       if (I0__PI_2I.in(-x0.min())) GECODE_ME_CHECK(x0.gq(home,0));
00156       #undef I0__PI_2I
00157     }
00158     GECODE_ES_CHECK(dopropagate(home,x0,x1));
00159     (void) new (home) Tan<A,B>(home,x0,x1);
00160     return ES_OK;
00161   }
00162 
00163   template<class A, class B>
00164   forceinline
00165   Tan<A,B>::Tan(Space& home, Tan<A,B>& p)
00166     : MixBinaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND>(home,p) {}
00167 
00168   template<class A, class B>
00169   Actor*
00170   Tan<A,B>::copy(Space& home) {
00171     return new (home) Tan<A,B>(home,*this);
00172   }
00173 
00174   template<class A, class B>
00175   ExecStatus
00176   Tan<A,B>::propagate(Space& home, const ModEventDelta&) {
00177     GECODE_ES_CHECK(dopropagate(home,x0,x1));
00178     return (x0.assigned()) ? home.ES_SUBSUMED(*this) : ES_FIX;
00179   }
00180 
00181   /*
00182    * Bounds consistent arc tangent operator
00183    *
00184    */
00185 
00186   template<class A, class B>
00187   forceinline
00188   ATan<A,B>::ATan(Home home, A x0, B x1)
00189     : MixBinaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND>(home,x0,x1) {}
00190 
00191   template<class A, class B>
00192   ExecStatus
00193   ATan<A,B>::post(Home home, A x0, B x1) {
00194     if (x0 == x1) {
00195       GECODE_ME_CHECK(x0.eq(home,0.0));
00196     } else {
00197       GECODE_ME_CHECK(x1.eq(home,atan(x0.domain())));
00198       GECODE_ME_CHECK(x0.eq(home,tan(x1.domain())));
00199       (void) new (home) ATan<A,B>(home,x0,x1);
00200     }
00201     return ES_OK;
00202   }
00203 
00204 
00205   template<class A, class B>
00206   forceinline
00207   ATan<A,B>::ATan(Space& home, ATan<A,B>& p)
00208     : MixBinaryPropagator<A,PC_FLOAT_BND,B,PC_FLOAT_BND>(home,p) {}
00209 
00210   template<class A, class B>
00211   Actor*
00212   ATan<A,B>::copy(Space& home) {
00213     return new (home) ATan<A,B>(home,*this);
00214   }
00215 
00216   template<class A, class B>
00217   ExecStatus
00218   ATan<A,B>::propagate(Space& home, const ModEventDelta&) {
00219     GECODE_ME_CHECK(x1.eq(home,atan(x0.domain())));
00220     GECODE_ME_CHECK(x0.eq(home,tan(x1.domain())));
00221     return (x0.assigned() && x1.assigned()) ? home.ES_SUBSUMED(*this) : ES_FIX;
00222   }
00223 
00224 }}}
00225 
00226 // STATISTICS: float-prop
00227