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// Geometric Tools, LLC
// Copyright (c) 1998-2014
// Distributed under the Boost Software License, Version 1.0.
// http://www.boost.org/LICENSE_1_0.txt
// http://www.geometrictools.com/License/Boost/LICENSE_1_0.txt
//
// File Version: 5.0.1 (2010/10/01)
#include "Wm5MathematicsPCH.h"
#include "Wm5Bisect1.h"
#include "Wm5Math.h"
namespace Wm5
{
//----------------------------------------------------------------------------
template <typename Real>
Bisect1<Real>::Bisect1 (Function function, int maxLevel, Real tolerance)
:
mFunction(function),
mMaxLevel(maxLevel),
mTolerance(tolerance)
{
}
//----------------------------------------------------------------------------
template <typename Real>
bool Bisect1<Real>::Bisect (Real x0, Real x1, Real& root)
{
// test two endpoints
Real f0 = mFunction(x0);
if (Math<Real>::FAbs(f0) <= mTolerance)
{
root = x0;
return true;
}
Real f1 = mFunction(x1);
if (Math<Real>::FAbs(f1) <= mTolerance)
{
root = x1;
return true;
}
if (f0*f1 > (Real)0)
{
return false;
}
for (int level = 0; level < mMaxLevel; ++level)
{
Real fXm = ((Real)0.5)*(x0 + x1);
Real fFm = mFunction(fXm);
if (Math<Real>::FAbs(fFm) <= mTolerance)
{
root = fXm;
return true;
}
if (f0*fFm < (Real)0)
{
x1 = fXm;
f1 = fFm;
}
else if (f1*fFm < (Real)0)
{
x0 = fXm;
f0 = fFm;
}
}
return false;
}
//----------------------------------------------------------------------------
//----------------------------------------------------------------------------
// Explicit instantiation.
//----------------------------------------------------------------------------
template WM5_MATHEMATICS_ITEM
class Bisect1<float>;
template WM5_MATHEMATICS_ITEM
class Bisect1<double>;
//----------------------------------------------------------------------------
}
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