src/exactinf.cpp

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