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/*
* $Revision: 2559 $
*
* last checkin:
* $Author: gutwenger $
* $Date: 2012-07-06 15:04:28 +0200 (Fr, 06. Jul 2012) $
***************************************************************/
/** \file
* \brief Declaration of class numexcept (handling of numeric problems).
*
* \author Stefan Hachul
*
* \par License:
* This file is part of the Open Graph Drawing Framework (OGDF).
*
* \par
* Copyright (C)<br>
* See README.txt in the root directory of the OGDF installation for details.
*
* \par
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* Version 2 or 3 as published by the Free Software Foundation;
* see the file LICENSE.txt included in the packaging of this file
* for details.
*
* \par
* This program 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.
*
* \par
* 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., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
* \see http://www.gnu.org/copyleft/gpl.html
***************************************************************/
#ifdef _MSC_VER
#pragma once
#endif
#ifndef OGDF_NUMEXCEPT_H
#define OGDF_NUMEXCEPT_H
#include "../basic/geometry.h"
namespace ogdf {
//--------------------------------------------------------------------------
// this class is developed for exceptions that might occure, when nodes are
// placed at the same position and a new random position has to be found, or
// when the calculated forces are near the machine accuracy, where no
// reasonable numeric and logic calculations are possible any more
//---------------------------------------------------------------------------
class numexcept
{
public:
//Returns a distinct random point within the smallest disque D with center
//old_point that is contained in the box defined by xmin,...,ymax; The size of
//D is shrunk by multiplying with epsilon = 0.1; Precondition:
//old_point is contained in the box and the box is not equal to old_point.
DPoint choose_distinct_random_point_in_disque(
DPoint old_point,
double xmin,
double xmax,
double ymin,
double ymax);
//A random point (distinct from old_pos) on the disque around old_pos with
//radius epsilon = 0.1 is computed.
DPoint choose_distinct_random_point_in_radius_epsilon(DPoint old_pos);
//If distance has a value near the machine precision the repulsive force calculation
//is not possible (calculated values exceed the machine accuracy) in this cases
//true is returned and force is set to a reasonable value that does
//not cause problems; Else false is returned and force keeps unchanged.
bool f_rep_near_machine_precision(double distance, DPoint& force);
//If distance has a value near the machine precision the (attractive)force
//calculation is not possible (calculated values exceed the machine accuracy) in
//this cases true is returned and force is set to a reasonable value that does
//not cause problems; Else false is returned and force keeps unchanged.
bool f_near_machine_precision(double distance, DPoint& force);
//Returns true if a is "nearly" equal to b (needed, when machine accuracy is
//insufficient in functions well_seperated and bordering of NMM)
bool nearly_equal(double a, double b);
};
}//namespace ogdf
#endif
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