KaplanMeier.h

#ifndef _theplu_yat_statistics_kaplan_meier
#define _theplu_yat_statistics_kaplan_meier

// $Id: KaplanMeier.h 4255 2022-12-16 03:11:14Z peter $

/*
  Copyright (C) 2022 Peter Johansson

  This file is part of the yat library, https://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 <https://www.gnu.org/licenses/>.
*/

#include <map>

namespace theplu {
namespace yat {
namespace statistics {

  class KaplanMeier
  {
  public:
    class TimePoint
    {
    public:
      TimePoint(void);

      TimePoint(unsigned int event, unsigned int censored);

      unsigned int at_risk(void) const;

      unsigned int censored(void) const;

      unsigned int event(void) const;

      double survival_proportion(void) const;
    private:
      friend class KaplanMeier;
      unsigned int censored_;
      unsigned int event_;
      unsigned int n_;
      double s_;
    };

    typedef std::map<double, TimePoint>::const_iterator const_iterator;

    KaplanMeier(void);

    void add(double time, bool event);

    void add(double time, unsigned int event, unsigned int censored);

    const_iterator begin(void) const;

    void clear(void);

    const_iterator end(void) const;

    const_iterator find(double time) const;

    const_iterator lower_bound(double time) const;

    const_iterator upper_bound(double time) const;
  private:
    // Calculated data in data_ is not calculated every time data is
    // added, but calculated lazily first when needed, i.e., when user
    // is accessing the data.
    mutable bool updated_;
    mutable std::map<double, TimePoint> data_;
    void update(void) const;
    unsigned int n_;
  };

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

#endif