source: branches/0.4-stable/yat/regression/Naive.cc @ 1392

// $Id: Naive.cc 1392 2008-07-28 19:35:30Z peter $

/*
  Copyright (C) 2004 Peter Johansson
  Copyright (C) 2005, 2006, 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 "Naive.h"
#include "OneDimensional.h"
#include "yat/statistics/Averager.h"
#include "yat/statistics/AveragerWeighted.h"
#include "yat/utility/VectorBase.h"

#include <cmath>
#include <iostream>

namespace theplu {
namespace yat {
namespace regression {

  Naive::Naive(void)
    : OneDimensional(), mse_(0.0)
  {
  }

  Naive::~Naive(void)
  {
  }


  void Naive::fit(const utility::VectorBase& x, const utility::VectorBase& y)
  {
    ap_.reset();
    for (size_t i=0; i<y.size(); i++)
      ap_.add(x(i),y(i));
    chisq_ = ap_.y_averager().sum_xx_centered();
  }


  double Naive::predict(const double x) const
  { 
    return ap_.y_averager().mean(); 
  }
  

  double Naive::s2(void) const
  {
    return chisq()/(ap_.n()-1);
  }


  double Naive::standard_error2(const double x) const
  {
    return s2()/ap_.n();
  }

}}} // of namespaces regression, yat, and theplu