SVindex.h

#ifndef _theplu_yat_classifier_sv_index_
#define _theplu_yat_classifier_sv_index_

// $Id: SVindex.h 4207 2022-08-26 04:36:28Z peter $

/*
  Copyright (C) 2006, 2007, 2008 Jari Häkkinen, Peter Johansson
  Copyright (C) 2013 Jari Häkkinen
  Copyright (C) 2022 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 <cstddef>
#include <vector>

namespace theplu {
namespace yat {

namespace utility {
  class Vector;
}

namespace classifier {

  class SVindex
  {

  public:
    SVindex();

    SVindex(const size_t);

    size_t index_first(void) const;

    size_t index_second(void) const;

    void init(const utility::Vector& alpha, const double);

    size_t nof_sv(void) const;

    void nsv_first(void);

    void nsv_second(void);

    void shuffle(void);

    size_t size(void) const;

    void sv_first(void);

    void sv_second(void);

    void update_first(const size_t i);

    void update_second(const size_t i);

    size_t value_first(void) const;

    size_t value_second(void) const;

    size_t operator()(size_t i) const;

  private:
    size_t index_first_;
    size_t index_second_;
    size_t nof_sv_;
    std::vector<size_t> vec_;
    size_t value_first_; // vec_[index_first_] exists for fast access
    size_t value_second_; // vec_[index_second_] exists for fast access

  };

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

#endif