lemon/math.h
author Peter Kovacs <kpeter@inf.elte.hu>
Tue, 09 Feb 2010 23:29:51 +0100
changeset 823 a7e93de12cbd
parent 470 81627fa1b007
child 877 141f9c0db4a3
permissions -rw-r--r--
Add a warning about huge capacities in Preflow (#319)
     1 /* -*- mode: C++; indent-tabs-mode: nil; -*-
     2  *
     3  * This file is a part of LEMON, a generic C++ optimization library.
     4  *
     5  * Copyright (C) 2003-2009
     6  * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
     7  * (Egervary Research Group on Combinatorial Optimization, EGRES).
     8  *
     9  * Permission to use, modify and distribute this software is granted
    10  * provided that this copyright notice appears in all copies. For
    11  * precise terms see the accompanying LICENSE file.
    12  *
    13  * This software is provided "AS IS" with no warranty of any kind,
    14  * express or implied, and with no claim as to its suitability for any
    15  * purpose.
    16  *
    17  */
    18 
    19 #ifndef LEMON_MATH_H
    20 #define LEMON_MATH_H
    21 
    22 ///\ingroup misc
    23 ///\file
    24 ///\brief Some extensions to the standard \c cmath library.
    25 ///
    26 ///Some extensions to the standard \c cmath library.
    27 ///
    28 ///This file includes the standard math library (cmath).
    29 
    30 #include<cmath>
    31 
    32 namespace lemon {
    33 
    34   /// \addtogroup misc
    35   /// @{
    36 
    37   /// The Euler constant
    38   const long double E       = 2.7182818284590452353602874713526625L;
    39   /// log_2(e)
    40   const long double LOG2E   = 1.4426950408889634073599246810018921L;
    41   /// log_10(e)
    42   const long double LOG10E  = 0.4342944819032518276511289189166051L;
    43   /// ln(2)
    44   const long double LN2     = 0.6931471805599453094172321214581766L;
    45   /// ln(10)
    46   const long double LN10    = 2.3025850929940456840179914546843642L;
    47   /// pi
    48   const long double PI      = 3.1415926535897932384626433832795029L;
    49   /// pi/2
    50   const long double PI_2    = 1.5707963267948966192313216916397514L;
    51   /// pi/4
    52   const long double PI_4    = 0.7853981633974483096156608458198757L;
    53   /// sqrt(2)
    54   const long double SQRT2   = 1.4142135623730950488016887242096981L;
    55   /// 1/sqrt(2)
    56   const long double SQRT1_2 = 0.7071067811865475244008443621048490L;
    57 
    58   ///Check whether the parameter is NaN or not
    59   
    60   ///This function checks whether the parameter is NaN or not.
    61   ///Is should be equivalent with std::isnan(), but it is not
    62   ///provided by all compilers.
    63   inline bool isNaN(double v)
    64     {
    65       return v!=v;
    66     }
    67 
    68   /// @}
    69 
    70 } //namespace lemon
    71 
    72 #endif //LEMON_TOLERANCE_H