include/dai/evidence.h

   1 /*  This file is part of libDAI - http://www.libdai.org/
   2  *
   3  *  Copyright (c) 2006-2011, The libDAI authors. All rights reserved.
   4  *
   5  *  Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
   6  */
   7
   8
   9 /// \file
  10 /// \brief Defines class Evidence, which stores multiple observations of joint states of variables
  11
  12
  13 #ifndef __defined_libdai_evidence_h
  14 #define __defined_libdai_evidence_h
  15
  16
  17 #include <istream>
  18 #include <dai/daialg.h>
  19
  20
  21 namespace dai {
  22
  23
  24 /// Stores a data set consisting of multiple samples, where each sample is the observed joint state of some variables.
  25 /** \note Each sample can describe the joint state of a different set of variables,
  26  *  in order to be able to deal with missing data.
  27  *
  28  *  \author Charles Vaske
  29  */
  30 class Evidence {
  31     public:
  32         /// Stores joint state of a set of variables
  33         typedef std::map<Var, size_t> Observation;
  34
  35     private:
  36         /// Each sample is an observed joint state of some variables
  37         std::vector<Observation> _samples;
  38
  39     public:
  40         /// Default constructor
  41         Evidence() : _samples() {}
  42
  43         /// Construct from \a samples
  44         Evidence( std::vector<Observation> &samples ) : _samples(samples) {}
  45
  46         /// Read in tabular data from a stream and add the read samples to \c *this.
  47         /** \param is Input stream in .tab file format, describing joint observations of variables in \a fg
  48          *  \param fg Factor graph describing the corresponding variables
  49          *  \see \ref fileformats-evidence
  50          *  \throw INVALID_EVIDENCE_FILE if the input stream is not valid
  51          */
  52         void addEvidenceTabFile( std::istream& is, FactorGraph& fg );
  53
  54         /// Returns number of stored samples
  55         size_t nrSamples() const { return _samples.size(); }
  56
  57     /// \name Iterator interface
  58     //@{
  59         /// Iterator over the samples
  60         typedef std::vector<Observation>::iterator iterator;
  61         /// Constant iterator over the samples
  62         typedef std::vector<Observation>::const_iterator const_iterator;
  63
  64         /// Returns iterator that points to the first sample
  65         iterator begin() { return _samples.begin(); }
  66         /// Returns constant iterator that points to the first sample
  67         const_iterator begin() const { return _samples.begin(); }
  68         /// Returns iterator that points beyond the last sample
  69         iterator end() { return _samples.end(); }
  70         /// Returns constant iterator that points beyond the last sample
  71         const_iterator end() const { return _samples.end(); }
  72     //@}
  73
  74     private:
  75         /// Read in tabular data from a stream and add the read samples to \c *this.
  76         void addEvidenceTabFile( std::istream& is, std::map<std::string, Var> &varMap );
  77 };
  78
  79
  80 } // end of namespace dai
  81
  82
  83 #endif