source: trunk/yat/statistics/Averager.h @ 2817

#ifndef _theplu_yat_statistics_averager_
#define _theplu_yat_statistics_averager_

// $Id: Averager.h 2817 2012-08-29 00:38:17Z peter $

/*
  Copyright (C) 2004 Jari Häkkinen, Peter Johansson
  Copyright (C) 2005, 2006 Jari Häkkinen, Peter Johansson, Markus Ringnér
  Copyright (C) 2007, 2008 Jari Häkkinen, Peter Johansson
  Copyright (C) 2009, 2010, 2011, 2012 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 "averager_base.h"

#include "yat/utility/iterator_traits.h"

#include <boost/concept_check.hpp>

#include <cmath>

namespace theplu{
namespace yat{
namespace statistics{

  ///
  /// @brief Class to calculate simple (first and second moments) averages.
  ///
  /// @see AveragerWeighted AveragerPair AveragerPairWeighted
  ///
  class Averager : public averager_base2<Averager>
  {
  public:

    ///
    /// Default constructor
    ///
    Averager(void);

    ///
    /// Constructor taking sum of \a x, sum of squared x, \a xx, and
    /// number of samples \a n.
    ///
    Averager(double x, double xx, long n);

    ///
    /// Copy constructor
    ///
    Averager(const Averager& a);

    ///
    /// @brief The assignment operator
    ///
    const Averager& operator=(const Averager&);

    /**
       \brief plus assignment operator

       Add another Averager
     */
    template<class Derived>
    const Averager& operator+=(const averager_base2<Derived>& other);

  private:
    friend class averager_base<Averager>;
    void add_impl(double, long int);
    void rescale_impl(double);
  };


  /**
     \brief adding a range of values to Averager \a a

     \relates Averager
   */
  template <typename InputIterator>
  void add(Averager& a, InputIterator first, InputIterator last)
  {
    BOOST_CONCEPT_ASSERT((boost::InputIterator<InputIterator>));
    utility::check_iterator_is_unweighted(first);
    for ( ; first != last; ++first)
      a.add(*first);
  }

  // template implementation
  template<class Derived>
  const Averager& Averager::operator+=(const averager_base2<Derived>& other)
  {
    if (other.n())
      add2(other.mean(), other.sum_xx_centered(), other.n());
    return *this;
  }


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

#endif