alpar@209: /* -*- mode: C++; indent-tabs-mode: nil; -*-
alpar@68:  *
alpar@209:  * This file is a part of LEMON, a generic C++ optimization library.
alpar@68:  *
alpar@1270:  * Copyright (C) 2003-2013
alpar@68:  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
alpar@68:  * (Egervary Research Group on Combinatorial Optimization, EGRES).
alpar@68:  *
alpar@68:  * Permission to use, modify and distribute this software is granted
alpar@68:  * provided that this copyright notice appears in all copies. For
alpar@68:  * precise terms see the accompanying LICENSE file.
alpar@68:  *
alpar@68:  * This software is provided "AS IS" with no warranty of any kind,
alpar@68:  * express or implied, and with no claim as to its suitability for any
alpar@68:  * purpose.
alpar@68:  *
alpar@68:  */
alpar@68: 
alpar@68: #ifndef LEMON_MATH_H
alpar@68: #define LEMON_MATH_H
alpar@68: 
alpar@68: ///\ingroup misc
alpar@68: ///\file
alpar@68: ///\brief Some extensions to the standard \c cmath library.
alpar@68: ///
alpar@68: ///Some extensions to the standard \c cmath library.
alpar@68: ///
alpar@68: ///This file includes the standard math library (cmath).
alpar@68: 
alpar@68: #include<cmath>
alpar@68: 
alpar@68: namespace lemon {
alpar@68: 
alpar@68:   /// \addtogroup misc
alpar@68:   /// @{
alpar@209: 
alpar@68:   /// The Euler constant
alpar@68:   const long double E       = 2.7182818284590452353602874713526625L;
alpar@68:   /// log_2(e)
alpar@68:   const long double LOG2E   = 1.4426950408889634073599246810018921L;
alpar@68:   /// log_10(e)
alpar@68:   const long double LOG10E  = 0.4342944819032518276511289189166051L;
alpar@68:   /// ln(2)
alpar@68:   const long double LN2     = 0.6931471805599453094172321214581766L;
alpar@68:   /// ln(10)
alpar@68:   const long double LN10    = 2.3025850929940456840179914546843642L;
alpar@68:   /// pi
alpar@68:   const long double PI      = 3.1415926535897932384626433832795029L;
alpar@68:   /// pi/2
alpar@68:   const long double PI_2    = 1.5707963267948966192313216916397514L;
alpar@68:   /// pi/4
alpar@68:   const long double PI_4    = 0.7853981633974483096156608458198757L;
alpar@68:   /// sqrt(2)
alpar@68:   const long double SQRT2   = 1.4142135623730950488016887242096981L;
alpar@68:   /// 1/sqrt(2)
alpar@68:   const long double SQRT1_2 = 0.7071067811865475244008443621048490L;
alpar@209: 
alpar@493:   ///Check whether the parameter is NaN or not
alpar@956: 
alpar@493:   ///This function checks whether the parameter is NaN or not.
alpar@493:   ///Is should be equivalent with std::isnan(), but it is not
alpar@493:   ///provided by all compilers.
alpar@558:   inline bool isNaN(double v)
alpar@493:     {
alpar@493:       return v!=v;
alpar@493:     }
alpar@68: 
alpar@1222:   ///Round a value to its closest integer
alpar@1222:   inline double round(double r) {
alpar@1311:     return (r > 0.0) ? std::floor(r + 0.5) : std::ceil(r - 0.5);
alpar@1222:   }
alpar@1222: 
alpar@68:   /// @}
alpar@68: 
alpar@68: } //namespace lemon
alpar@68: 
alpar@1222: #endif //LEMON_MATH_H