include/dai/evidence.h

   1 /*  This file is part of libDAI - http://www.libdai.org/
   2  *
   3  *  libDAI is licensed under the terms of the GNU General Public License version
   4  *  2, or (at your option) any later version. libDAI is distributed without any
   5  *  warranty. See the file COPYING for more details.
   6  *
   7  *  Copyright (C) 2009  Charles Vaske  [cvaske at soe dot ucsc dot edu]
   8  *  Copyright (C) 2009  University of California, Santa Cruz
   9  */
  10
  11
  12 /// \file
  13 /// \brief Defines class Evidence, which stores multiple observations of joint states of variables
  14
  15
  16 #ifndef __defined_libdai_evidence_h
  17 #define __defined_libdai_evidence_h
  18
  19
  20 #include <istream>
  21 #include <dai/daialg.h>
  22
  23
  24 namespace dai {
  25
  26
  27 /// Stores a data set consisting of multiple samples, where each sample is the observed joint state of some variables.
  28 /** \note Each sample can describe the joint state of a different set of variables,
  29  *  in order to be able to deal with missing data.
  30  *
  31  *  \author Charles Vaske
  32  */
  33 class Evidence {
  34     public:
  35         /// Stores joint state of a set of variables
  36         typedef std::map<Var, size_t> Observation;
  37
  38     private:
  39         /// Each sample is an observed joint state of some variables
  40         std::vector<Observation> _samples;
  41
  42     public:
  43         /// Default constructor
  44         Evidence() : _samples() {}
  45
  46         /// Construct from \a samples
  47         Evidence( std::vector<Observation> &samples ) : _samples(samples) {}
  48
  49         /// Read in tabular data from a stream and add the read samples to \c *this.
  50         /** \param is Input stream in .tab file format, describing joint observations of variables in \a fg
  51          *  \param fg Factor graph describing the corresponding variables
  52          *  \see \ref fileformats-evidence
  53          *  \throw INVALID_EVIDENCE_FILE if the input stream is not valid
  54          */
  55         void addEvidenceTabFile( std::istream& is, FactorGraph& fg );
  56
  57         /// Returns number of stored samples
  58         size_t nrSamples() const { return _samples.size(); }
  59
  60     /// \name Iterator interface
  61     //@{
  62         /// Iterator over the samples
  63         typedef std::vector<Observation>::iterator iterator;
  64         /// Constant iterator over the samples
  65         typedef std::vector<Observation>::const_iterator const_iterator;
  66
  67         /// Returns iterator that points to the first sample
  68         iterator begin() { return _samples.begin(); }
  69         /// Returns constant iterator that points to the first sample
  70         const_iterator begin() const { return _samples.begin(); }
  71         /// Returns iterator that points beyond the last sample
  72         iterator end() { return _samples.end(); }
  73         /// Returns constant iterator that points beyond the last sample
  74         const_iterator end() const { return _samples.end(); }
  75     //@}
  76
  77     private:
  78         /// Read in tabular data from a stream and add the read samples to \c *this.
  79         void addEvidenceTabFile( std::istream& is, std::map<std::string, Var> &varMap );
  80 };
  81
  82
  83 } // end of namespace dai
  84
  85
  86 #endif