source: trunk/yat/utility/sort_index.h @ 1495

#ifndef _theplu_yat_utility_sort_index_
#define _theplu_yat_utility_sort_index_ 

// $Id: sort_index.h 1495 2008-09-12 14:58:35Z peter $

/*
  Copyright (C) 2008 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 "StrideIterator.h"

#include <gsl/gsl_sort.h>

#include <algorithm>
#include <iterator>
#include <vector>

namespace theplu {
namespace yat {
namespace utility {

  /**
     Create a vector \a sort_index containing the indeces of elements
     in a range [first, last). The elements of \a sort_index give the
     index of the range element which would have been stored in that
     position if the range had been sorted in place. The first element
     of \a sort_index gives the index of the least element in the
     range, and the last element of \a sort_index gives the index of
     the greatest element in the range. The function will not affect
     the range, i.e., ForwardIterator can be read-only.

     \since New in yat 0.5
  */
  template<typename ForwardIterator>
  void sort_index(ForwardIterator first, ForwardIterator last, 
                  std::vector<size_t>& sort_index);
    
    
  /**
     Specialization for StrideIterator<double*>

     \since New in yat 0.5
  */
  void sort_index(StrideIterator<double*> first, 
                  StrideIterator<double*> last, 
                  std::vector<size_t>& sort_index);

  /**
     Specialization for StrideIterator<const double*>

     \since New in yat 0.5
  */
  void sort_index(StrideIterator<const double*> first, 
                  StrideIterator<const double*> last, 
                  std::vector<size_t>& sort_index);

  /**
     Specialization for std::vector<double>::iterator

     \since New in yat 0.5
  */
  void sort_index(std::vector<double>::iterator first, 
                  std::vector<double>::iterator last, 
                  std::vector<size_t>& sort_index);

  /**
     Specialization for std::vector<double>::const_iterator

     \since New in yat 0.5
  */
  void sort_index(std::vector<double>::const_iterator first, 
                  std::vector<double>::const_iterator last, 
                  std::vector<size_t>& sort_index);


  //  template implementation

  template<typename ForwardIterator>
  void sort_index(ForwardIterator first, ForwardIterator last, 
                  std::vector<size_t>& result)
  {
    std::vector<double> vec;
    vec.reserve(std::distance(first, last));
    std::copy(first, last, 
              std::back_insert_iterator<std::vector<double> >(vec));
    sort_index(vec.begin(), vec.end(), result);
  }

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

#endif