Polynomial.hpp

/*
 * This file is part of bogus, a C++ sparse block matrix library.
 *
 * Copyright 2013 Gilles Daviet <gdaviet@gmail.com>
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/


#ifndef BOGUS_POLYNOMIAL_HPP
#define BOGUS_POLYNOMIAL_HPP

namespace bogus
{

namespace polynomial {

enum RealRootsFilter
{
    StrictlyPositiveRoots,
    StrictlyNegativeRoots,
    AllRoots
} ;

template< unsigned Dimension, typename Scalar >
struct RootsFinder
{
    static unsigned getRealRoots( const Scalar* coeffs,
                                  Scalar* realRoots,
                                  RealRootsFilter filter = AllRoots ) ;
} ;

template< unsigned Dimension, typename Scalar >
struct PossiblyDegenerateRootsFinder
{
    static unsigned getRealRoots( Scalar* coeffs,
                                  Scalar* realRoots,
                                  RealRootsFilter filter = AllRoots ) ;
} ;


template< unsigned Dimension, typename Scalar >
unsigned getRealRoots( const Scalar (&coeffs)[Dimension],
                       Scalar (&realRoots)[Dimension],
                       RealRootsFilter filter = AllRoots )
{
    return RootsFinder< Dimension, Scalar >::getRealRoots( coeffs, realRoots, filter ) ;
}


template< unsigned Dimension, typename Scalar >
unsigned getRealRoots( Scalar (&coeffs)[Dimension+1],
                       Scalar (&realRoots)[Dimension],
                       RealRootsFilter filter = AllRoots )
{
    return PossiblyDegenerateRootsFinder< Dimension, Scalar >::getRealRoots( coeffs, realRoots, filter ) ;
}

} //namespace polynomial

} //namespace bogus

#endif