/* -*- mode: C++; indent-tabs-mode: nil; -*-

  *

  * This file is a part of LEMON, a generic C++ optimization library.

  *

  * Copyright (C) 2003-2013

  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

  * (Egervary Research Group on Combinatorial Optimization, EGRES).

  *

  * Permission to use, modify and distribute this software is granted

  * provided that this copyright notice appears in all copies. For

  * precise terms see the accompanying LICENSE file.

  *

  * This software is provided "AS IS" with no warranty of any kind,

  * express or implied, and with no claim as to its suitability for any

  * purpose.

  *

  */

 #ifndef LEMON_MATH_H

 #define LEMON_MATH_H

 ///\ingroup misc

 ///\file

 ///\brief Some extensions to the standard \c cmath library.

 ///

 ///Some extensions to the standard \c cmath library.

 ///

 ///This file includes the standard math library (cmath).

 #include<cmath>

 namespace lemon {

   /// \addtogroup misc

   /// @{

   /// The Euler constant

   const long double E       = 2.7182818284590452353602874713526625L;

   /// log_2(e)

   const long double LOG2E   = 1.4426950408889634073599246810018921L;

   /// log_10(e)

   const long double LOG10E  = 0.4342944819032518276511289189166051L;

   /// ln(2)

   const long double LN2     = 0.6931471805599453094172321214581766L;

   /// ln(10)

   const long double LN10    = 2.3025850929940456840179914546843642L;

   /// pi

   const long double PI      = 3.1415926535897932384626433832795029L;

   /// pi/2

   const long double PI_2    = 1.5707963267948966192313216916397514L;

   /// pi/4

   const long double PI_4    = 0.7853981633974483096156608458198757L;

   /// sqrt(2)

   const long double SQRT2   = 1.4142135623730950488016887242096981L;

   /// 1/sqrt(2)

   const long double SQRT1_2 = 0.7071067811865475244008443621048490L;

   ///Check whether the parameter is NaN or not

   ///This function checks whether the parameter is NaN or not.

   ///Is should be equivalent with std::isnan(), but it is not

   ///provided by all compilers.

   inline bool isNaN(double v)

     {

       return v!=v;

     }

   ///Round a value to its closest integer

   inline double round(double r) {

     return (r > 0.0) ? std::floor(r + 0.5) : std::ceil(r - 0.5);

   }

   /// @}

 } //namespace lemon

 #endif //LEMON_MATH_H