source: trunk/yat/statistics/Histogram.cc @ 1437

// $Id: Histogram.cc 1437 2008-08-25 17:55:00Z peter $

/*
  Copyright (C) 2004 Jari Häkkinen
  Copyright (C) 2005 Peter Johansson
  Copyright (C) 2006 Jari Häkkinen
  Copyright (C) 2007 Jari Häkkinen, Peter Johansson
  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 2 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 this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  02111-1307, USA.
*/

#include "Histogram.h"

#include <cmath>
#include <fstream>

namespace theplu {
namespace yat {
namespace statistics {


  Histogram::Histogram(void)
    : xmax_(0), xmin_(0), sum_all_(), sum_histogram_()
  {
  }


  Histogram::Histogram(const Histogram& b)
  {
    *this=b;
  }


  Histogram::Histogram(const double min, const double max, const size_t n)
    : histogram_(std::vector<double>(n,0.0)),
      xmax_(max), xmin_(min),
      sum_all_(), sum_histogram_()
  {
  }


  Histogram::~Histogram(void)
  {
  }


  int Histogram::add(const double x, const double w)
  {
    sum_all_.add(x,w);
    if (x<xmin_)
      return -1;
    else if (x>=xmax_)
      return 1;

    sum_histogram_.add(x,w);
    histogram_[bin(x)] += w;
    return 0;
  }


  const AveragerWeighted& Histogram::averager_all(void) const
  {
    return sum_all_;
  }


  const AveragerWeighted& Histogram::averager_histogram(void) const
  {
    return sum_histogram_;
  }


  size_t Histogram::bin(double d)
  {
    return (((d<xmin_) || (d>xmax_)) ? 0 :
            static_cast<size_t>(floor((d-xmin_)/spacing() )));
  }


  size_t Histogram::nof_bins(void) const
  {
    return histogram_.size();
  }


  void Histogram::normalize(bool choice)
  {
    double scale_factor;
    if (choice) 
      scale_factor = sum_all_.sum_w();
    else
      scale_factor = sum_all_.sum_w()*spacing();
    for (size_t i=0; i<histogram_.size(); i++)
      histogram_[i]/=scale_factor;
  }


  double Histogram::observation_value(const size_t k) const
  {
    return xmin_+spacing()*(k+0.5);
  }


  void Histogram::reset(void)
  {
    for (size_t i=0; i<histogram_.size(); i++)
      histogram_[i]=0;
    sum_all_.reset();
    sum_histogram_.reset();
  }


  double Histogram::spacing(void) const
  {
    return (xmax_-xmin_)/nof_bins();
  }


  double Histogram::xmax(void) const
  {
    return xmax_;
  }


  double Histogram::xmin(void) const
  {
    return xmin_;
  }


  double Histogram::operator[](size_t k) const
  {
    return histogram_[k];
  }


  const Histogram& Histogram::operator=(const Histogram& b)
  {
    if (this==&b)
      return *this;
    histogram_=b.histogram_;
    xmax_=b.xmax_;
    xmin_=b.xmin_;
    sum_all_=b.sum_all_;
    sum_histogram_=b.sum_histogram_;
    return *this;
  }


  std::ostream& operator<<(std::ostream& s,const Histogram& histogram)
  {
    s << "# histogram min : " << histogram.xmin() << '\n';
    s << "# histogram max : " << histogram.xmax() << '\n';
    s << "# number of bins: " << histogram.nof_bins() << '\n';
    s << "# nof points in histogram : " 
      << histogram.averager_histogram().sum_w() << '\n';
    s << "# nof points in total:      " 
      << histogram.averager_all().sum_w() << '\n';
    s << "# column 1: center of observation bin\n"
      << "# column 2: frequency\n";

    for (size_t i=0; i<histogram.nof_bins(); i++) {
      s.width(12);
      s << histogram.observation_value(i);
      s.width(12);
      s << histogram[i] << '\n';
    }

    return s;
  }

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