include/dai/bp.h

   1 /*  Copyright (C) 2006-2008  Joris Mooij  [j dot mooij at science dot ru dot nl]
   2     Radboud University Nijmegen, The Netherlands
   3
   4     This file is part of libDAI.
   5
   6     libDAI is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     libDAI is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with libDAI; if not, write to the Free Software
  18     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19 */
  20
  21
  22 #ifndef __defined_libdai_bp_h
  23 #define __defined_libdai_bp_h
  24
  25
  26 #include <string>
  27 #include <dai/daialg.h>
  28 #include <dai/factorgraph.h>
  29 #include <dai/enum.h>
  30
  31
  32 namespace dai {
  33
  34
  35 class BP : public DAIAlgFG {
  36     protected:
  37         typedef std::vector<size_t> ind_t;
  38         struct EdgeProp {
  39             ind_t  index;
  40             Prob   message;
  41             Prob   newMessage;
  42             double residual;
  43         };
  44
  45         std::vector<std::vector<EdgeProp> > edges;
  46
  47     public:
  48         ENUM4(UpdateType,SEQFIX,SEQRND,SEQMAX,PARALL)
  49         UpdateType Updates() const { return GetPropertyAs<UpdateType>("updates"); }
  50
  51         // default constructor
  52         BP() : DAIAlgFG() {};
  53         // copy constructor
  54         BP(const BP & x) : DAIAlgFG(x), edges(x.edges) {};
  55         BP* clone() const { return new BP(*this); }
  56         // construct BP object from FactorGraph
  57         BP(const FactorGraph & fg, const Properties &opts) : DAIAlgFG(fg, opts) {
  58             assert( checkProperties() );
  59             Regenerate();
  60         }
  61         // assignment operator
  62         BP & operator=(const BP & x) {
  63             if(this!=&x) {
  64                 DAIAlgFG::operator=(x);
  65                 edges = x.edges;
  66             }
  67             return *this;
  68         }
  69
  70         static const char *Name;
  71
  72         Prob & message(size_t i, size_t _I) { return edges[i][_I].message; }
  73         const Prob & message(size_t i, size_t _I) const { return edges[i][_I].message; }
  74         Prob & newMessage(size_t i, size_t _I) { return edges[i][_I].newMessage; }
  75         const Prob & newMessage(size_t i, size_t _I) const { return edges[i][_I].newMessage; }
  76         ind_t & index(size_t i, size_t _I) { return edges[i][_I].index; }
  77         const ind_t & index(size_t i, size_t _I) const { return edges[i][_I].index; }
  78         double & residual(size_t i, size_t _I) { return edges[i][_I].residual; }
  79         const double & residual(size_t i, size_t _I) const { return edges[i][_I].residual; }
  80         void findMaxResidual( size_t &i, size_t &_I );
  81
  82         std::string identify() const;
  83         void Regenerate();
  84         void init();
  85         void calcNewMessage( size_t i, size_t _I );
  86         double run();
  87         Factor beliefV (size_t i) const;
  88         Factor beliefF (size_t I) const;
  89         Factor belief (const Var &n) const;
  90         Factor belief (const VarSet &n) const;
  91         std::vector<Factor> beliefs() const;
  92         Complex logZ() const;
  93
  94         void init( const VarSet &ns );
  95         void undoProbs( const VarSet &ns ) { FactorGraph::undoProbs(ns); init(ns); }
  96         bool checkProperties();
  97 };
  98
  99
 100 } // end of namespace dai
 101
 102
 103 #endif