include/dai/mf.h

   1 /*  This file is part of libDAI - http://www.libdai.org/
   2  *
   3  *  libDAI is licensed under the terms of the GNU General Public License version
   4  *  2, or (at your option) any later version. libDAI is distributed without any
   5  *  warranty. See the file COPYING for more details.
   6  *
   7  *  Copyright (C) 2006-2009  Joris Mooij  [joris dot mooij at libdai dot org]
   8  *  Copyright (C) 2006-2007  Radboud University Nijmegen, The Netherlands
   9  */
  10
  11
  12 /// \file
  13 /// \brief Defines class MF
  14 /// \todo Improve documentation
  15
  16
  17 #ifndef __defined_libdai_mf_h
  18 #define __defined_libdai_mf_h
  19
  20
  21 #include <string>
  22 #include <dai/daialg.h>
  23 #include <dai/factorgraph.h>
  24 #include <dai/properties.h>
  25
  26
  27 namespace dai {
  28
  29
  30 /// Approximate inference algorithm "Mean Field"
  31 class MF : public DAIAlgFG {
  32     private:
  33         std::vector<Factor>  _beliefs;
  34         /// Maximum difference encountered so far
  35         Real _maxdiff;
  36         /// Number of iterations needed
  37         size_t _iters;
  38
  39     public:
  40         /// Parameters of this inference algorithm
  41         struct Properties {
  42             /// Verbosity
  43             size_t verbose;
  44
  45             /// Maximum number of iterations
  46             size_t maxiter;
  47
  48             /// Tolerance
  49             Real tol;
  50
  51             /// Damping constant
  52             Real damping;
  53         } props;
  54
  55         /// Name of this inference algorithm
  56         static const char *Name;
  57
  58     public:
  59         /// Default constructor
  60         MF() : DAIAlgFG(), _beliefs(), _maxdiff(0.0), _iters(0U), props() {}
  61
  62         /// Construct from FactorGraph fg and PropertySet opts
  63         MF( const FactorGraph &fg, const PropertySet &opts ) : DAIAlgFG(fg), _beliefs(), _maxdiff(0.0), _iters(0U), props() {
  64             setProperties( opts );
  65             construct();
  66         }
  67
  68
  69         /// @name General InfAlg interface
  70         //@{
  71         virtual MF* clone() const { return new MF(*this); }
  72         virtual std::string identify() const;
  73         virtual Factor belief( const Var &n ) const;
  74         virtual Factor belief( const VarSet &ns ) const;
  75         virtual std::vector<Factor> beliefs() const;
  76         virtual Real logZ() const;
  77         virtual void init();
  78         virtual void init( const VarSet &ns );
  79         virtual Real run();
  80         virtual Real maxDiff() const { return _maxdiff; }
  81         virtual size_t Iterations() const { return _iters; }
  82         //@}
  83
  84
  85         /// @name Additional interface specific for MF
  86         //@{
  87         Factor beliefV( size_t i ) const;
  88         //@}
  89
  90     private:
  91         void construct();
  92         void setProperties( const PropertySet &opts );
  93         PropertySet getProperties() const;
  94         std::string printProperties() const;
  95 };
  96
  97
  98 } // end of namespace dai
  99
 100
 101 #endif