include/dai/regiongraph.h

   1 /*  Copyright (C) 2006-2008  Joris Mooij  [joris dot mooij at tuebingen dot mpg dot de]
   2     Radboud University Nijmegen, The Netherlands /
   3     Max Planck Institute for Biological Cybernetics, Germany
   4
   5     This file is part of libDAI.
   6
   7     libDAI is free software; you can redistribute it and/or modify
   8     it under the terms of the GNU General Public License as published by
   9     the Free Software Foundation; either version 2 of the License, or
  10     (at your option) any later version.
  11
  12     libDAI is distributed in the hope that it will be useful,
  13     but WITHOUT ANY WARRANTY; without even the implied warranty of
  14     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15     GNU General Public License for more details.
  16
  17     You should have received a copy of the GNU General Public License
  18     along with libDAI; if not, write to the Free Software
  19     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  20 */
  21
  22
  23 /// \file
  24 /// \brief Defines classes Region, FRegion and RegionGraph
  25 /// \todo Improve documentation
  26
  27
  28 #ifndef __defined_libdai_regiongraph_h
  29 #define __defined_libdai_regiongraph_h
  30
  31
  32 #include <iostream>
  33 #include <dai/bipgraph.h>
  34 #include <dai/factorgraph.h>
  35 #include <dai/weightedgraph.h>
  36
  37
  38 namespace dai {
  39
  40
  41 /// A Region is a set of variables with a counting number
  42 class Region : public VarSet {
  43     private:
  44         /// Counting number
  45         double          _c;
  46
  47     public:
  48         /// Default constructor
  49         Region() : VarSet(), _c(1.0) {}
  50
  51         /// Construct Region from a VarSet and a counting number
  52         Region(const VarSet & x, double c) : VarSet(x), _c(c) {}
  53
  54         /// Provide read access to counting number
  55         const double & c() const { return _c; }
  56         /// Provide full access to counting number
  57         double & c() { return _c; }
  58 };
  59
  60
  61 /// A FRegion is a factor with a counting number
  62 class FRegion : public Factor {
  63     private:
  64         /// Counting number
  65         double _c;
  66
  67     public:
  68         /// Default constructor
  69         FRegion() : Factor(), _c(1.0) {}
  70
  71         /// Constructs FRegion from a Factor and a counting number
  72         FRegion( const Factor & x, double c ) : Factor(x), _c(c) {}
  73
  74         /// Provide read access to counting number
  75         const double & c() const { return _c; }
  76         /// Provide full access to counting number
  77         double & c() { return _c; }
  78 };
  79
  80
  81 /// A RegionGraph is a bipartite graph consisting of outer regions (type FRegion) and inner regions (type Region)
  82 class RegionGraph : public FactorGraph {
  83     public:
  84         /// Stores the neighborhood structure
  85         BipartiteGraph          G;
  86
  87         /// The outer regions (corresponding to nodes of type 1)
  88         std::vector<FRegion>    ORs;
  89
  90         /// The inner regions (corresponding to nodes of type 2)
  91         std::vector<Region>     IRs;
  92
  93         /// Stores for each factor index the index of the outer region it belongs to
  94         std::vector<size_t>     fac2OR;
  95
  96
  97     public:
  98         /// Default constructor
  99         RegionGraph() : FactorGraph(), G(), ORs(), IRs(), fac2OR() {}
 100
 101         /// Constructs a RegionGraph from a FactorGraph
 102         RegionGraph( const FactorGraph &fg ) : FactorGraph(fg), G(), ORs(), IRs(), fac2OR() {}
 103
 104         /// Constructs a RegionGraph from a FactorGraph, a vector of outer regions, a vector of inner regions and a vector of edges
 105         RegionGraph( const FactorGraph &fg, const std::vector<Region> &ors, const std::vector<Region> &irs, const std::vector<std::pair<size_t,size_t> > &edges );
 106
 107         /// Constructs a RegionGraph from a FactorGraph and a vector of outer VarSets (CVM style)
 108         RegionGraph( const FactorGraph &fg, const std::vector<VarSet> &cl );
 109
 110         /// Clone *this (virtual copy constructor)
 111         virtual RegionGraph* clone() const { return new RegionGraph(*this); }
 112
 113         /// Create (virtual default constructor)
 114         virtual RegionGraph* create() const { return new RegionGraph(); }
 115
 116         /// Set the content of the I'th factor and make a backup of its old content if backup == true
 117         virtual void setFactor( size_t I, const Factor &newFactor, bool backup = false ) {
 118             FactorGraph::setFactor( I, newFactor, backup );
 119             RecomputeOR( I );
 120         }
 121
 122         /// Set the contents of all factors as specified by facs and make a backup of the old contents if backup == true
 123         virtual void setFactors( const std::map<size_t, Factor> & facs, bool backup = false ) {
 124             FactorGraph::setFactors( facs, backup );
 125             VarSet ns;
 126             for( std::map<size_t, Factor>::const_iterator fac = facs.begin(); fac != facs.end(); fac++ )
 127                 ns |= fac->second.vars();
 128             RecomputeORs( ns );
 129         }
 130
 131
 132         /// Provides read access to outer region
 133         const FRegion & OR(size_t alpha) const { return ORs[alpha]; }
 134         /// Provides access to outer region
 135         FRegion & OR(size_t alpha) { return ORs[alpha]; }
 136
 137         /// Provides read access to inner region
 138         const Region & IR(size_t beta) const { return IRs[beta]; }
 139         /// Provides access to inner region
 140         Region & IR(size_t beta) { return IRs[beta]; }
 141
 142         /// Returns number of outer regions
 143         size_t nrORs() const { return ORs.size(); }
 144         /// Returns number of inner regions
 145         size_t nrIRs() const { return IRs.size(); }
 146
 147
 148         /// Provides read access to neighbors of outer region
 149         const Neighbors & nbOR( size_t alpha ) const { return G.nb1(alpha); }
 150         /// Provides full access to neighbors of outer region
 151         Neighbors & nbOR( size_t alpha ) { return G.nb1(alpha); }
 152
 153         /// Provides read access to neighbors of inner region
 154         const Neighbors & nbIR( size_t beta ) const { return G.nb2(beta); }
 155         /// Provides full access to neighbors of inner region
 156         Neighbors & nbIR( size_t beta ) { return G.nb2(beta); }
 157
 158
 159         /// Calculates counting numbers of inner regions based upon counting numbers of outer regions
 160         void Calc_Counting_Numbers();
 161         /// Check whether the counting numbers are valid
 162         bool Check_Counting_Numbers();
 163
 164         /// Recompute all outer regions
 165         void RecomputeORs();
 166
 167         /// Recompute all outer regions involving the variables in ns
 168         void RecomputeORs( const VarSet & ns );
 169
 170         /// Recompute all outer regions involving factor I
 171         void RecomputeOR( size_t I );
 172
 173         // Friends
 174         friend std::ostream & operator << ( std::ostream & os, const RegionGraph & rg );
 175 };
 176
 177
 178 } // end of namespace dai
 179
 180
 181 #endif