src/evidence.cpp

   1 /*  Copyright (C) 2009  Charles Vaske  [cvaske at soe dot ucsc dot edu]
   2     University of California Santa Cruz
   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 <sstream>
  23 #include <string>
  24 #include <cstdlib>
  25
  26 #include <dai/util.h>
  27 #include <dai/evidence.h>
  28
  29
  30 namespace dai {
  31
  32
  33 void Observation::addObservation( Var node, size_t setting ) {
  34     _obs[node] = setting;
  35 }
  36
  37
  38 void Observation::applyEvidence( InfAlg &alg ) const {
  39     for( std::map<Var, size_t>::const_iterator i = _obs.begin(); i != _obs.end(); ++i )
  40         alg.clamp( alg.fg().findVar(i->first), i->second );
  41 }
  42
  43
  44 void Evidence::addEvidenceTabFile( std::istream &is, FactorGraph &fg ) {
  45     std::map<std::string, Var> varMap;
  46     for( std::vector<Var>::const_iterator v = fg.vars().begin(); v != fg.vars().end(); ++v ) {
  47         std::stringstream s;
  48         s << v->label();
  49         varMap[s.str()] = *v;
  50     }
  51
  52     addEvidenceTabFile( is, varMap );
  53 }
  54
  55
  56 void Evidence::addEvidenceTabFile( std::istream &is, std::map<std::string, Var> &varMap ) {
  57     std::string line;
  58     getline( is, line );
  59
  60     // Parse header
  61     std::vector<std::string> header_fields;
  62     tokenizeString( line, header_fields );
  63     std::vector<std::string>::const_iterator p_field = header_fields.begin();
  64     if( p_field == header_fields.end() )
  65         DAI_THROW(INVALID_EVIDENCE_FILE);
  66
  67     std::vector<Var> vars;
  68     for( ; p_field != header_fields.end(); ++p_field ) {
  69         std::map<std::string, Var>::iterator elem = varMap.find( *p_field );
  70         if( elem == varMap.end() )
  71             DAI_THROW(INVALID_EVIDENCE_FILE);
  72         vars.push_back( elem->second );
  73     }
  74
  75     // Read samples
  76     while( getline(is, line) ) {
  77         std::vector<std::string> fields;
  78         tokenizeString( line, fields );
  79         if( fields.size() != vars.size() )
  80             DAI_THROW(INVALID_EVIDENCE_FILE);
  81
  82         Observation sampleData;
  83         for( size_t i = 0; i < vars.size(); ++i ) {
  84             if( fields[i].size() > 0 ) { // skip if missing observation
  85                 if( fields[i].find_first_not_of("0123456789") != std::string::npos )
  86                     DAI_THROW(INVALID_EVIDENCE_FILE);
  87                 size_t state = atoi( fields[i].c_str() );
  88                 if( state >= vars[i].states() )
  89                     DAI_THROW(INVALID_EVIDENCE_FILE);
  90                 sampleData.addObservation( vars[i], state );
  91             }
  92         }
  93         _samples.push_back( sampleData );
  94     } // finished sample line
  95 }
  96
  97
  98 } // end of namespace dai