Fisher.h

#ifndef _theplu_yat_statistics_fisher_
#define _theplu_yat_statistics_fisher_

// $Id: Fisher.h 3562 2017-01-04 01:16:07Z peter $

/*
  Copyright (C) 2004, 2005 Peter Johansson
  Copyright (C) 2006, 2007, 2008 Jari Häkkinen, Peter Johansson
  Copyright (C) 2009, 2011, 2013, 2014, 2015, 2017 Peter Johansson

  This file is part of the yat library, http://dev.thep.lu.se/yat

  The yat library is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License as
  published by the Free Software Foundation; either version 3 of the
  License, or (at your option) any later version.

  The yat library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with yat. If not, see <http://www.gnu.org/licenses/>.
*/

#include <yat/utility/deprecate.h>

namespace theplu {
namespace yat {
namespace statistics {

  class Fisher
  {

  public:
    Fisher(bool yates=false);

    virtual ~Fisher(void);


    double Chi2(void) const;

    void expected(double& a, double& b, double& c, double& d) const;

    unsigned int& minimum_size(void);

    const unsigned int& minimum_size(void) const;

    double p_left(void) const;

    double p_right(void) const;

    double p_value(void) const;

    double p_value_one_sided() const YAT_DEPRECATE;

    double oddsratio(const unsigned int a, const unsigned int b,
                     const unsigned int c, const unsigned int d);

    double oddsratio(void) const;

  private:
    bool calculate_p_exact(void) const;

    // two-sided
    double p_value_approximative(void) const;
    // two-sided
    double p_value_exact(void) const;
    // calculate two-sided p-value to get k (or fewer) wins when
    // drawing t samples out of of a population of n1 wins and n2 losses
    double p_value_exact(unsigned int k, unsigned int n1, unsigned int n2,
                         unsigned int t) const;

    double lower_tail(unsigned int k, unsigned int n1, unsigned int n2,
                      unsigned int t) const;

    // return P(X=k+1) / P(X=k)
    double hypergeometric_ratio(unsigned int k, unsigned int n1,
                                unsigned int n2, unsigned int t) const;
    double choose_ratio(unsigned int n, unsigned int k) const;

    double p_left_exact(void) const;
    double p_right_exact(void) const;

    double yates(unsigned int o, double e) const;

    unsigned int a_;
    unsigned int b_;
    unsigned int c_;
    unsigned int d_;
    unsigned int minimum_size_;
    double oddsratio_;
    bool yates_;
  };

}}} // of namespace statistics, yat, and theplu

#endif