math.hh

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// -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
// vi: set et ts=4 sw=2 sts=2:
#ifndef DUNE_MATH_HH
#define DUNE_MATH_HH
 
#include <cmath>
#include <complex>
 
namespace Dune
{
 
  template< class Field >
  struct MathematicalConstants;
 
  template< class T >
  struct StandardMathematicalConstants
  {
    static const T e ()
    {
      using std::exp;
      static const T e = exp( T( 1 ) );
      return e;
    }
 
    static const T pi ()
    {
      using std::acos;
      static const T pi = acos( T( -1 ) );
      return pi;
    }
  };
 
 
#ifndef DOXYGEN
  // MathematicalConstants for float
  // -------------------------------
 
  template<>
  struct MathematicalConstants< float >
    : public StandardMathematicalConstants< float >
  {};
 
 
 
  // MathematicalConstants for double
  // --------------------------------
 
  template<>
  struct MathematicalConstants< double >
    : public StandardMathematicalConstants< double >
  {};
 
 
 
  // MathematicalConstants for long double
  // -------------------------------------
 
  template<>
  struct MathematicalConstants< long double >
    : public StandardMathematicalConstants< long double >
  {};
#endif // DOXYGEN
 
 
  template <int m>
  struct Factorial
  {
    enum { factorial = m * Factorial<m-1>::factorial };
  };
 
  template <>
  struct Factorial<0>
  {
    // 0! = 1
    enum { factorial = 1 };
  };
 
  // conjugate complex does nothing for non-complex types
  template<class K>
  inline K conjugateComplex (const K& x)
  {
    return x;
  }
 
#ifndef DOXYGEN
  // specialization for complex
  template<class K>
  inline std::complex<K> conjugateComplex (const std::complex<K>& c)
  {
    return std::complex<K>(c.real(),-c.imag());
  }
#endif
 
  template <class T>
  int sign(const T& val)
  {
    return (val < 0 ? -1 : 1);
  }
 
}
 
#endif // #ifndef DUNE_MATH_HH