src/exactinf.cpp

   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 #include <dai/exactinf.h>
  24 #include <sstream>
  25
  26
  27 namespace dai {
  28
  29
  30 using namespace std;
  31
  32
  33 const char *ExactInf::Name = "EXACT";
  34
  35
  36 void ExactInf::setProperties( const PropertySet &opts ) {
  37     assert( opts.hasKey("verbose") );
  38
  39     props.verbose = opts.getStringAs<size_t>("verbose");
  40 }
  41
  42
  43 PropertySet ExactInf::getProperties() const {
  44     PropertySet opts;
  45     opts.Set( "verbose", props.verbose );
  46     return opts;
  47 }
  48
  49
  50 string ExactInf::printProperties() const {
  51     stringstream s( stringstream::out );
  52     s << "[";
  53     s << "verbose=" << props.verbose << "]";
  54     return s.str();
  55 }
  56
  57
  58 void ExactInf::construct() {
  59     // clear variable beliefs and reserve space
  60     _beliefsV.clear();
  61     _beliefsV.reserve( nrVars() );
  62     for( size_t i = 0; i < nrVars(); i++ )
  63         _beliefsV.push_back( Factor( var(i) ) );
  64
  65     // clear factor beliefs and reserve space
  66     _beliefsF.clear();
  67     _beliefsF.reserve( nrFactors() );
  68     for( size_t I = 0; I < nrFactors(); I++ )
  69         _beliefsF.push_back( Factor( factor(I).vars() ) );
  70 }
  71
  72
  73 void ExactInf::init() {
  74     for( size_t i = 0; i < nrVars(); i++ )
  75         _beliefsV[i].fill( 1.0 );
  76     for( size_t I = 0; I < nrFactors(); I++ )
  77         _beliefsF[I].fill( 1.0 );
  78 }
  79
  80
  81 double ExactInf::run() {
  82     if( props.verbose >= 1 )
  83         cerr << "Starting " << identify() << "...";
  84
  85     Factor P;
  86     for( size_t I = 0; I < nrFactors(); I++ )
  87         P *= factor(I);
  88
  89     Real Z = P.sum();
  90     _logZ = std::log(Z);
  91     for( size_t i = 0; i < nrVars(); i++ )
  92         _beliefsV[i] = P.marginal(var(i));
  93     for( size_t I = 0; I < nrFactors(); I++ )
  94         _beliefsF[I] = P.marginal(factor(I).vars());
  95
  96     if( props.verbose >= 1 )
  97         cerr << "finished" << endl;
  98
  99     return 0.0;
 100 }
 101
 102
 103 vector<Factor> ExactInf::beliefs() const {
 104     vector<Factor> result = _beliefsV;
 105     result.insert( result.end(), _beliefsF.begin(), _beliefsF.end() );
 106     return result;
 107 }
 108
 109
 110 Factor ExactInf::belief( const VarSet &ns ) const {
 111     if( ns.size() == 0 )
 112         return Factor();
 113     else if( ns.size() == 1 ) {
 114         return belief( *(ns.begin()) );
 115     } else {
 116         size_t I;
 117         for( I = 0; I < nrFactors(); I++ )
 118             if( factor(I).vars() >> ns )
 119                 break;
 120         assert( I != nrFactors() );
 121         return beliefF(I).marginal(ns);
 122     }
 123 }
 124
 125
 126 string ExactInf::identify() const {
 127     return string(Name) + printProperties();
 128 }
 129
 130
 131 } // end of namespace dai