source: trunk/lib/classifier/Target.h @ 514

// $Id: Target.h 514 2006-02-20 09:45:34Z peter $

#ifndef _theplu_classifier_target_ 
#define _theplu_classifier_target_ 

#include <c++_tools/utility/Exception.h>

#include <cassert>
#include <map>
#include <string>
#include <vector>


namespace theplu {
namespace classifier {  

  ///
  /// Class for targets
  ///

  class Target
  {
  
  public:
    ///
    /// @brief Constructor creating target with @a labels
    ///
    Target(const std::vector<std::string>& labels);

    ///
    /// @brief istream constructor.
    ///
    Target(std::istream&, char sep='\0') 
      throw (utility::IO_error,std::exception);

    ///
    /// @brief Copy Constructor 
    ///
    //inline Target(const Target& other) 
    //  : classes_(other.classes_), class_map_(other.class_map_), 
    //    labels_(other.labels_) {}

    ///
    /// Constructor creating a sub-Target from Target @a org. @a vec
    /// defines which indices to use.
    ///
    /// @note class is preserved, i.e., operator() returns the same
    /// for the Target as the original Target.
    ///
    Target(const Target& org, const std::vector<size_t>& vec);

    ///
    /// @brief Destructor
    ///
    ~Target();

    ///
    /// @return a map with label as key and class as value.
    ///
    inline const std::map<std::string,size_t>& classes(void) const 
    { return class_map_; }
    
    ///
    /// This function is equivalent to Target::classes().size()
    ///
    /// @return number of classes
    ///
    inline const size_t nof_classes(void) const { return classes().size(); }

    ///
    /// Default binary is set to false for all classes except class 0
    ///
    /// @return true if class of sample @a i is set to true
    ///
    /// @see set_binary
    ///
    inline bool binary(const size_t i) const 
    { assert(i<size()); return binary_[i]; }
    
    ///
    /// Class @a target is set to @a b. Default is binary set to false
    /// for each class.
    ///
    void set_binary(const size_t target, const bool b); 

    ///
    /// @return number of samples
    ///
    inline size_t size(void) const { return classes_.size(); }

    ///
    /// @return number of samples with label @a label
    ///
    const size_t size(const std::string& label) const;

    ///
    /// @return the class of @a sample
    ///
    inline size_t operator()(const size_t sample) const 
    { assert(sample<size()); return classes_[sample]; }


  private:
    std::vector<short> binary_; // avoid using vector<bool>
    std::vector<size_t> classes_; // class of sample i
    std::map<std::string,size_t> class_map_;  
    std::vector<std::string> labels_; // label of class i
    
    void init(const std::vector<std::string>&);

  };  
  
  ///
  /// The output operator for the Target class.
  ///
  std::ostream& operator<<(std::ostream&, const Target& );

}} // of namespace classifier and namespace theplu

#endif