include/dai/mf.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 class MF
  25 /// \todo Improve documentation
  26
  27
  28 #ifndef __defined_libdai_mf_h
  29 #define __defined_libdai_mf_h
  30
  31
  32 #include <string>
  33 #include <dai/daialg.h>
  34 #include <dai/factorgraph.h>
  35 #include <dai/properties.h>
  36
  37
  38 namespace dai {
  39
  40
  41 /// Approximate inference algorithm "Mean Field"
  42 class MF : public DAIAlgFG {
  43     private:
  44         std::vector<Factor>  _beliefs;
  45         /// Maximum difference encountered so far
  46         double _maxdiff;
  47         /// Number of iterations needed
  48         size_t _iters;
  49
  50     public:
  51         /// Parameters of this inference algorithm
  52         struct Properties {
  53             /// Verbosity
  54             size_t verbose;
  55
  56             /// Maximum number of iterations
  57             size_t maxiter;
  58
  59             /// Tolerance
  60             double tol;
  61
  62             /// Damping constant
  63             double damping;
  64         } props;
  65
  66         /// Name of this inference algorithm
  67         static const char *Name;
  68
  69     public:
  70         /// Default constructor
  71         MF() : DAIAlgFG(), _beliefs(), _maxdiff(0.0), _iters(0U), props() {}
  72
  73         /// Construct from FactorGraph fg and PropertySet opts
  74         MF( const FactorGraph &fg, const PropertySet &opts ) : DAIAlgFG(fg), _beliefs(), _maxdiff(0.0), _iters(0U), props() {
  75             setProperties( opts );
  76             construct();
  77         }
  78
  79
  80         /// @name General InfAlg interface
  81         //@{
  82         virtual MF* clone() const { return new MF(*this); }
  83         virtual MF* create() const { return new MF(); }
  84         virtual std::string identify() const;
  85         virtual Factor belief( const Var &n ) const;
  86         virtual Factor belief( const VarSet &ns ) const;
  87         virtual std::vector<Factor> beliefs() const;
  88         virtual Real logZ() const;
  89         virtual void init();
  90         virtual void init( const VarSet &ns );
  91         virtual double run();
  92         virtual double maxDiff() const { return _maxdiff; }
  93         virtual size_t Iterations() const { return _iters; }
  94         //@}
  95
  96
  97         /// @name Additional interface specific for MF
  98         //@{
  99         Factor beliefV( size_t i ) const;
 100         //@}
 101
 102     private:
 103         void construct();
 104         void setProperties( const PropertySet &opts );
 105         PropertySet getProperties() const;
 106         std::string printProperties() const;
 107 };
 108
 109
 110 } // end of namespace dai
 111
 112
 113 #endif