lemon/math.h
author Peter Kovacs <kpeter@inf.elte.hu>
Thu, 12 Nov 2009 23:26:13 +0100
changeset 806 fa6f37d7a25b
parent 470 81627fa1b007
child 877 141f9c0db4a3
permissions -rw-r--r--
Entirely rework CapacityScaling (#180)

- Use the new interface similarly to NetworkSimplex.
- Rework the implementation using an efficient internal structure
for handling the residual network. This improvement made the
code much faster (up to 2-5 times faster on large graphs).
- Handle GEQ supply type (LEQ is not supported).
- Handle negative costs for arcs of finite capacity.
(Note that this algorithm cannot handle arcs of negative cost
and infinite upper bound, thus it returns UNBOUNDED if such
an arc exists.)
- Extend the documentation.
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/* -*- mode: C++; indent-tabs-mode: nil; -*-
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 *
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 * This file is a part of LEMON, a generic C++ optimization library.
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 *
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 * Copyright (C) 2003-2009
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 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
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 * (Egervary Research Group on Combinatorial Optimization, EGRES).
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 *
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 * Permission to use, modify and distribute this software is granted
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 * provided that this copyright notice appears in all copies. For
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 * precise terms see the accompanying LICENSE file.
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 *
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 * This software is provided "AS IS" with no warranty of any kind,
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 * express or implied, and with no claim as to its suitability for any
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 * purpose.
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 *
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 */
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#ifndef LEMON_MATH_H
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#define LEMON_MATH_H
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///\ingroup misc
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///\file
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///\brief Some extensions to the standard \c cmath library.
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///
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///Some extensions to the standard \c cmath library.
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///
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///This file includes the standard math library (cmath).
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#include<cmath>
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namespace lemon {
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  /// \addtogroup misc
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  /// @{
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  /// The Euler constant
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  const long double E       = 2.7182818284590452353602874713526625L;
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  /// log_2(e)
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  const long double LOG2E   = 1.4426950408889634073599246810018921L;
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  /// log_10(e)
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  const long double LOG10E  = 0.4342944819032518276511289189166051L;
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  /// ln(2)
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  const long double LN2     = 0.6931471805599453094172321214581766L;
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  /// ln(10)
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  const long double LN10    = 2.3025850929940456840179914546843642L;
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  /// pi
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  const long double PI      = 3.1415926535897932384626433832795029L;
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  /// pi/2
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  const long double PI_2    = 1.5707963267948966192313216916397514L;
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  /// pi/4
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  const long double PI_4    = 0.7853981633974483096156608458198757L;
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  /// sqrt(2)
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  const long double SQRT2   = 1.4142135623730950488016887242096981L;
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  /// 1/sqrt(2)
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  const long double SQRT1_2 = 0.7071067811865475244008443621048490L;
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  ///Check whether the parameter is NaN or not
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  ///This function checks whether the parameter is NaN or not.
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  ///Is should be equivalent with std::isnan(), but it is not
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  ///provided by all compilers.
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  inline bool isNaN(double v)
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    {
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      return v!=v;
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    }
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  /// @}
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} //namespace lemon
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#endif //LEMON_TOLERANCE_H