source: trunk/c++_tools/statistics/SNR.h @ 623

#ifndef _theplu_statistics_snr
#define _theplu_statistics_snr

// $Id: SNR.h 623 2006-09-05 02:13:12Z peter $

#include <c++_tools/statistics/Score.h>

#include <gsl/gsl_cdf.h>

namespace theplu {
  namespace utility {
    class vector;
  }
  namespace classifier {
    class DataLookWeighted1D;
  }
namespace statistics {  

  ///
  /// @brief Class for score based on signal-to-noise ratio (SNR).  
  ///
  /// Also
  /// sometimes referred to as Golub score. The score is the ratio
  /// between difference in mean and the sum of standard deviations
  /// for two groups.  \f$ \frac{ \frac{1}{n_x}\sum x_i -
  /// \frac{1}{n_y}\sum y_i }{ \sigma_x + \sigma_y} \f$ where \f$
  /// \sigma \f$ is standard deviation.
  ///   
  class SNR : public Score
  {
  
  public:
    ///
    /// Default Constructor.
    ///
    SNR(bool absolute=true);

    ///
    /// Calculates the value of SNR score. @return SNR score if
    /// absolute=true absolute value of t-score is returned
    ///
    double score(const classifier::Target& target, 
                 const utility::vector& value); 

    ///
    /// Weighted version of SNR @return t-score if absolute=true
    /// absolute value of t-score is returned.
    ///
    double score(const classifier::Target& target, 
                 const classifier::DataLookupWeighted1D& value);          

    ///
    /// Weighted version of SNR @return t-score if absolute=true
    /// absolute value of t-score is returned.
    ///
    double score(const classifier::Target& target, 
                 const utility::vector& value, 
                 const utility::vector& weight);          
  private:
    double score_;
  };

}} // of namespace statistics and namespace theplu

#endif