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 string ExactInf::printProperties() const {
  50     stringstream s( stringstream::out );
  51     s << "[";
  52     s << "verbose=" << props.verbose << "]";
  53     return s.str();
  54 }
  55
  56
  57 void ExactInf::create() {
  58     // clear variable beliefs and reserve space
  59     _beliefsV.clear();
  60     _beliefsV.reserve( nrVars() );
  61     for( size_t i = 0; i < nrVars(); i++ )
  62         _beliefsV.push_back( Factor( var(i) ) );
  63
  64     // clear factor beliefs and reserve space
  65     _beliefsF.clear();
  66     _beliefsF.reserve( nrFactors() );
  67     for( size_t I = 0; I < nrFactors(); I++ )
  68         _beliefsF.push_back( Factor( factor(I).vars() ) );
  69 }
  70
  71
  72 void ExactInf::init() {
  73     for( size_t i = 0; i < nrVars(); i++ )
  74         _beliefsV[i].fill( 1.0 );
  75     for( size_t I = 0; I < nrFactors(); I++ )
  76         _beliefsF[I].fill( 1.0 );
  77 }
  78
  79
  80 double ExactInf::run() {
  81     if( props.verbose >= 1 )
  82         cout << "Starting " << identify() << "...";
  83
  84     Factor P;
  85     for( size_t I = 0; I < nrFactors(); I++ )
  86         P *= factor(I);
  87
  88     Real Z = P.totalSum();
  89     _logZ = std::log(Z);
  90     for( size_t i = 0; i < nrVars(); i++ )
  91         _beliefsV[i] = P.marginal(var(i));
  92     for( size_t I = 0; I < nrFactors(); I++ )
  93         _beliefsF[I] = P.marginal(factor(I).vars());
  94
  95     if( props.verbose >= 1 )
  96         cout << "finished" << endl;
  97
  98     return 0.0;
  99 }
 100
 101
 102 vector<Factor> ExactInf::beliefs() const {
 103     vector<Factor> result = _beliefsV;
 104     result.insert( result.end(), _beliefsF.begin(), _beliefsF.end() );
 105     return result;
 106 }
 107
 108
 109 Factor ExactInf::belief( const VarSet &ns ) const {
 110     if( ns.size() == 0 )
 111         return Factor();
 112     else if( ns.size() == 1 ) {
 113         return belief( *(ns.begin()) );
 114     } else {
 115         size_t I;
 116         for( I = 0; I < nrFactors(); I++ )
 117             if( factor(I).vars() >> ns )
 118                 break;
 119         assert( I != nrFactors() );
 120         return beliefF(I).marginal(ns);
 121     }
 122 }
 123
 124
 125 string ExactInf::identify() const {
 126     return string(Name) + printProperties();
 127 }
 128
 129
 130 } // end of namespace dai