vectorTools.H

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/*---------------------------------------------------------------------------*\
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-------------------------------------------------------------------------------
    Copyright (C) 2011-2016 OpenFOAM Foundation
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.
 
    OpenFOAM 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 3 of the License, or
    (at your option) any later version.
 
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    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 OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 
Class
    Foam::vectorTools
 
Description
    Functions for analysing the relationships between vectors
 
\*---------------------------------------------------------------------------*/
 
#ifndef vectorTools_H
#define vectorTools_H
 
#include "vector.H"
#include "unitConversion.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
 
/*---------------------------------------------------------------------------*\
                      Namespace vectorTools Declaration
\*---------------------------------------------------------------------------*/
 
//- Collection of functions for testing relationships between two vectors.
namespace vectorTools
{
    //- Test if a and b are parallel: a^b = 0
    //  Uses the cross product, so the tolerance is proportional to
    //  the sine of the angle between a and b in radians
    template<class T>
    bool areParallel
    (
        const Vector<T>& a,
        const Vector<T>& b,
        const T& tolerance = SMALL
    )
    {
        return (mag(a ^ b) < tolerance) ? true : false;
//        return ( mag( mag(a & b)/(mag(a)*mag(b)) - 1.0 ) < tolerance )
//               ? true
//               : false;
    }
 
    //- Test if a and b are orthogonal: a.b = 0
    //  Uses the dot product, so the tolerance is proportional to
    //  the cosine of the angle between a and b in radians
    template<class T>
    bool areOrthogonal
    (
        const Vector<T>& a,
        const Vector<T>& b,
        const T& tolerance = SMALL
    )
    {
        return (mag(a & b) < tolerance) ? true : false;
    }
 
    //- Test if angle between a and b is acute: a.b > 0
    template<class T>
    bool areAcute
    (
        const Vector<T>& a,
        const Vector<T>& b
    )
    {
        return ((a & b) > 0) ? true : false;
    }
 
    //- Test if angle between a and b is obtuse: a.b < 0
    template<class T>
    bool areObtuse
    (
        const Vector<T>& a,
        const Vector<T>& b
    )
    {
        return ((a & b) < 0) ? true : false;
    }
 
    //- Calculate angle between a and b in radians
    template<class T>
    T cosPhi
    (
        const Vector<T>& a,
        const Vector<T>& b,
        const T& tolerance = SMALL
    )
    {
        scalar cosPhi = (a & b)/(mag(a)*mag(b) + tolerance);
 
        // Enforce bounding between -1 and 1
        return min(max(cosPhi, -1), 1);
    }
 
    //- Calculate angle between a and b in radians
    template<class T>
    T radAngleBetween
    (
        const Vector<T>& a,
        const Vector<T>& b,
        const T& tolerance = SMALL
    )
    {
        scalar cosPhi = (a & b)/(mag(a)*mag(b) + tolerance);
 
        // Enforce bounding between -1 and 1
        return acos( min(max(cosPhi, -1), 1) );
    }
 
    //- Calculate angle between a and b in degrees
    template<class T>
    T degAngleBetween
    (
        const Vector<T>& a,
        const Vector<T>& b,
        const T& tolerance = SMALL
    )
    {
        return radToDeg(radAngleBetween(a, b, tolerance));
    }
 
} // End namespace vectorTools
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //