// $Id: KernelTriCube.cc 1000 2007-12-23 20:09:15Z jari $

/*
	Copyright (C) 2005 Peter Johansson
	Copyright (C) 2006 Jari Häkkinen
	Copyright (C) 2007 Peter Johansson

	This file is part of the yat library, http://trac.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 "KernelTriCube.h"
#include "Kernel.h"

#include <cmath>

namespace theplu {
namespace yat {
namespace regression {

	KernelTriCube::KernelTriCube(void)
		: Kernel()
	{
	}

	double KernelTriCube::operator()(const double x) const
	{
		if (x>1 || x<-1)
			return 0.0;
		else
			return pow(1-pow(fabs(x),3),3);
	}

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