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 SampleData::addObservation( Var node, size_t setting ) {
  34     _obs[node] = setting;
  35 }
  36
  37
  38 void SampleData::applyEvidence( InfAlg& alg ) const {
  39     std::map<Var, size_t>::const_iterator i = _obs.begin();
  40     for( ; i != _obs.end(); ++i )
  41         alg.clamp( i->first, i->second );
  42 }
  43
  44
  45 void Evidence::addEvidenceTabFile( std::istream& is, FactorGraph& fg ) {
  46     std::map<std::string, Var> varMap;
  47     std::vector<Var>::const_iterator v = fg.vars().begin();
  48     for( ; v != fg.vars().end(); ++v ) {
  49         std::stringstream s;
  50         s << v->label();
  51         varMap[s.str()] = *v;
  52     }
  53
  54     addEvidenceTabFile( is, varMap );
  55 }
  56
  57
  58 void Evidence::addEvidenceTabFile( std::istream& is, std::map<std::string, Var>& varMap ) {
  59     std::vector<std::string> header_fields;
  60     std::vector<Var> vars;
  61     std::string line;
  62     getline( is, line );
  63
  64     // Parse header
  65     tokenizeString( line, header_fields );
  66     std::vector<std::string>::const_iterator p_field = header_fields.begin();
  67
  68     if( p_field == header_fields.end() )
  69         DAI_THROW(INVALID_EVIDENCE_LINE);
  70
  71     ++p_field; // first column are sample labels
  72     for( ; p_field != header_fields.end(); ++p_field ) {
  73         std::map<std::string, Var>::iterator elem = varMap.find( *p_field );
  74         if( elem == varMap.end() )
  75             DAI_THROW(INVALID_EVIDENCE_FILE);
  76         vars.push_back( elem->second );
  77     }
  78
  79     // Read samples
  80     while( getline(is, line) ) {
  81         std::vector<std::string> fields;
  82
  83         tokenizeString( line, fields );
  84
  85         if( fields.size() != vars.size() + 1 )
  86             DAI_THROW(INVALID_EVIDENCE_LINE);
  87
  88         SampleData& sampleData = _samples[fields[0]];
  89         sampleData.name( fields[0] ); // in case of a new sample
  90         for( size_t i = 0; i < vars.size(); ++i ) {
  91             if( fields[i+1].size() > 0 ) { // skip if missing observation
  92                 if( fields[i+1].find_first_not_of("0123456789") != std::string::npos )
  93                     DAI_THROW(INVALID_EVIDENCE_OBSERVATION);
  94                 size_t state = atoi( fields[i+1].c_str() );
  95                 if( state >= vars[i].states() )
  96                     DAI_THROW(INVALID_EVIDENCE_OBSERVATION);
  97                 sampleData.addObservation( vars[i], state );
  98             }
  99         }
 100     } // finished sample line
 101 }
 102
 103
 104 } // end of namespace dai