#ifndef __JMATH__JQUANTILE_T__
#define __JMATH__JQUANTILE_T__

#include <vector>
#include <algorithm>
#include <numeric>

#include "JLang/JException.hh"

/**
 * \author mdejong
 */
namespace JMATH {}
namespace JPP { using namespace JMATH; }

namespace JMATH {

  using JLANG::JDivisionByZero;

  /**
   * Auxiliary data structure for average.
   *
   * The determination of the average should be independent of the order of the input values. 
   */
  struct JQuantile_t {
    /**
     * Default constructor.
     */
    JQuantile_t()
    {
      reset();
    }


    /**
     * Reset.
     */
    void reset()
    {
      buffer.clear();
    }


    /**
     * Put value.
     *
     * \param  x           value
     */
    void put(const double x)
    {
      buffer.push_back(x);
    }


    /**
     * Get mean value.
     *
     * \return             mean value
     */
    double getMean() const
    {
      using namespace std;

      if (!buffer.empty()) {

	sort(buffer.begin(), buffer.end());
	
	return accumulate(buffer.begin(), buffer.end(), 0.0) / buffer.size();
      }

      THROW(JDivisionByZero, "JQuantile_t::getMean()");
    }


    /**
     * Get mean value.
     *
     * \param  value       default value
     * \return             mean value
     */
    double getMean(const double value) const
    {
      if (!buffer.empty())
        return getMean();
      else
        return value;
    }

  private:
    mutable std::vector<double> buffer;
  };
}

#endif