floating_point_comparison.h

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/** @file
 *  @author Bram de Greve (bramz@users.sourceforge.net)
 *  @author Tom De Muer (tomdemuer@users.sourceforge.net)
 *
 *  *** BEGIN LICENSE INFORMATION ***
 *  
 *  The contents of this file are subject to the Common Public Attribution License 
 *  Version 1.0 (the "License"); you may not use this file except in compliance with 
 *  the License. You may obtain a copy of the License at 
 *  http://lass.sourceforge.net/cpal-license. The License is based on the 
 *  Mozilla Public License Version 1.1 but Sections 14 and 15 have been added to cover 
 *  use of software over a computer network and provide for limited attribution for 
 *  the Original Developer. In addition, Exhibit A has been modified to be consistent 
 *  with Exhibit B.
 *  
 *  Software distributed under the License is distributed on an "AS IS" basis, WITHOUT 
 *  WARRANTY OF ANY KIND, either express or implied. See the License for the specific 
 *  language governing rights and limitations under the License.
 *  
 *  The Original Code is LASS - Library of Assembled Shared Sources.
 *  
 *  The Initial Developer of the Original Code is Bram de Greve and Tom De Muer.
 *  The Original Developer is the Initial Developer.
 *  
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 *  Copyright (C) 2004-2007 the Initial Developer.
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 *  GNU General Public License Version 2 or later (the GPL), in which case the 
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 */



#ifndef LASS_GUARDIAN_OF_INCLUSION_NUM_TOLERANCE_COMPARISON_H
#define LASS_GUARDIAN_OF_INCLUSION_NUM_TOLERANCE_COMPARISON_H

#include "num_common.h"
#include "basic_ops.h"

namespace lass
{
namespace num
{

template <typename T>
bool almostEqual(T iA, T iB, T iRelativeTolerance)
{
    return num::abs(iA - iB) < iRelativeTolerance * std::max(num::abs(iA), num::abs(iB));
}

template <typename T>
bool notAlmostEqual(T iA, T iB, T iRelativeTolerance)
{
    return !almostEqual(iA, iB, iRelativeTolerance);
}

template <typename T>
bool almostLess(T iA, T iB, T iRelativeTolerance)
{
    return iA < iB && !almostEqual(iA, iB, iRelativeTolerance);
}

template <typename T>
bool almostGreater(T iA, T iB, T iRelativeTolerance)
{
    return iA > iB && !almostEqual(iA, iB, iRelativeTolerance);
}

template <typename T>
bool almostLessOrEqual(T iA, T iB, T iRelativeTolerance)
{
    return iA <= iB || almostEqual(iA, iB, iRelativeTolerance);
}

template <typename T>
bool almostGreaterOrEqual(T iA, T iB, T iRelativeTolerance)
{
    return iA >= iB || almostEqual(iA, iB, iRelativeTolerance);
}

template <typename T>
bool almostInOpenRange(T iA, T iMin, T iMax, T iRelativeTolerance)
{
    return almostGreater(iA, iMin, iRelativeTolerance) && 
        almostLess(iA, iMax, iRelativeTolerance);
}

template <typename T>
bool almostInClosedRange(T iA, T iMin, T iMax, T iRelativeTolerance)
{
    return almostGreaterOrEqual(iA, iMin, iRelativeTolerance) && 
        almostLessOrEqual(iA, iMax, iRelativeTolerance);
}

}

}

#endif