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eepp/include/eepp/math/mtrand.hpp
Martí­n Lucas Golini 35955a80bd Math module refactored.
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branch : dev
2017-02-14 23:23:24 -03:00

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// MersenneTwister.h
// Mersenne Twister random number generator -- a C++ class MTRand
// Based on code by Makoto Matsumoto, Takuji Nishimura, and Shawn Cokus
// Richard J. Wagner v1.1 28 September 2009 wagnerr@umich.edu
// The Mersenne Twister is an algorithm for generating random numbers. It
// was designed with consideration of the flaws in various other generators.
// The period, 2^19937-1, and the order of equidistribution, 623 dimensions,
// are far greater. The generator is also fast; it avoids multiplication and
// division, and it benefits from caches and pipelines. For more information
// see the inventors' web page at
// http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
// Reference
// M. Matsumoto and T. Nishimura, "Mersenne Twister: A 623-Dimensionally
// Equidistributed Uniform Pseudo-Random Number Generator", ACM Transactions on
// Modeling and Computer Simulation, Vol. 8, No. 1, January 1998, pp 3-30.
// Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
// Copyright (C) 2000 - 2009, Richard J. Wagner
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// 3. The names of its contributors may not be used to endorse or promote
// products derived from this software without specific prior written
// permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
// The original code included the following notice:
//
// When you use this, send an email to: m-mat@math.sci.hiroshima-u.ac.jp
// with an appropriate reference to your work.
//
// It would be nice to CC: wagnerr@umich.edu and Cokus@math.washington.edu
// when you write.
// Adapted to EE++ ( this is not the original file ).
// Added RandRange.
#ifndef EE_MATHCMTRAND_HPP
#define EE_MATHCMTRAND_HPP
#include <eepp/config.hpp>
namespace EE { namespace Math {
class EE_API MTRand {
public:
static const Uint32 M = 397;
static const Int32 N = 624;
static const Uint32 SAVE = N + 1;
/** Initialize with a defined user seed */
MTRand( const Uint32 oneSeed );
/** Initialize with a predefined seed */
MTRand();
/** Initialize with a copy of another MTRand object */
MTRand( const MTRand& o );
/** Copy MTRand object */
MTRand& operator=( const MTRand& o );
/** @return integer in [0,2^32-1] */
Uint32 randi();
/** @return integer in [0,n] for n < 2^32 */
Uint32 randi( const Uint32 n );
/** @return real number in [0,1] */
double rand();
/** @return real number in [0,n] */
double rand( const double n );
/** Set a new seed */
void seed( const Uint32 oneSeed );
/** Set the default seed */
void seed();
/** @return float number in [0,1] */
Float randf();
/** @return float number in [0,n] */
Float randf( const Float n );
/** @return int number in [Min,Max] */
int randRange( int Min, int Max );
/** @return float number in [Min,Max] */
Float randRange( Float Min, Float Max );
/** Save the state to an allocated array */
void save( Uint32* saveArray ) const;
/** Load state from an array */
void load( Uint32 *const loadArray );
protected:
Uint32 mState[N];
Uint32 * mNext;
int mLeft;
void initialize( const Uint32 oneSeed );
void reload();
Uint32 hiBit( const Uint32 u ) const;
Uint32 loBit( const Uint32 u ) const;
Uint32 loBits( const Uint32 u ) const;
Uint32 mixBits( const Uint32 u, const Uint32 v ) const;
Uint32 magic( const Uint32 u ) const;
Uint32 twist( const Uint32 m, const Uint32 s0, const Uint32 s1 ) const;
};
}}
#endif