116 lines
2.9 KiB
C++
116 lines
2.9 KiB
C++
//This file is part of Photon (http://photon.sourceforge.net)
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//Copyright (C) 2004-2005 James Turk
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//
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// Author:
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// James Turk (jpt2433@rit.edu)
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//
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// Version:
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// $Id: RandGen.hpp,v 1.5 2005/07/18 06:18:51 cozman Exp $
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#ifndef PHOTON_UTIL_RANDGEN_HPP
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#define PHOTON_UTIL_RANDGEN_HPP
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namespace photon
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{
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namespace util
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{
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// Class: RandGen
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// Psuedorandom number generator class which uses Mersenne Twister.
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// MT19937 is described at <http://www.math.keio.ac.jp/matumoto/emt.html>.
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class RandGen
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{
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// Group: (Con/De)structors
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public:
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// Function: RandGen
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// Constructor for random generator, using time as seed.
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RandGen();
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// Function: RandGen
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// Constructor for random generator, allowing specific seed.
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//
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// Parameters:
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// seedVal - Seed for random generator, a given seed will always turn out
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// the same string of random numbers.
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//
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// See Also:
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// <seed>
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RandGen(unsigned long seedVal);
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// Group: General
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public:
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// Function: seed
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// Reseed random generator, a given seed will always turn out same string
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// of random numbers.
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//
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// Parameters:
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// seed - Seed for random generator.
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void seed(unsigned long seedVal);
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// Function: genRand
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// Obtain random number in range [0,max).
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//
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// Parameters:
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// max - Boundary for random number.
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//
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// Returns:
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// Random number from 0 to max-1.
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unsigned long genRand(unsigned long max);
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// Function: genRand
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// Obtain random integer in range [min,max].
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//
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// Parameters:
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// min - Minimum boundary for random number.
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// max - Maximum boundary for random number.
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//
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// Returns:
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// Random number from min to max.
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int genRand(int min, int max);
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// Function: genRand
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// Obtain random double in range [min,max].
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//
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// Parameters:
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// min - Minimum boundary for random number.
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// max - Maximum boundary for random number.
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//
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// Returns:
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// Random number from min to max.
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double genRand(double min, double max);
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// Function: genRandSign
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// Obtain random sign, positive or negative.
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//
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// Returns:
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// Either -1.0 or +1.0
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double genRandSign();
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// Function: genRand01
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// Obtain random double in range [0,1).
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//
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// Returns:
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// Random number from 0 to under 1.
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double genRand01();
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private: // utilities
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unsigned long genrand_int32(); //base of all generation
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private: // constants
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static const unsigned long N = 624;
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static const unsigned long M = 397;
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static const unsigned long MATRIX_A = 0x9908b0dfUL;
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static const unsigned long UPPER_MASK = 0x80000000UL;
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static const unsigned long LOWER_MASK = 0x7fffffffUL;
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private: //state data
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unsigned long stateVector_[N];
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unsigned long stateVectorIndex_;
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};
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}
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}
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#endif //PHOTON_UTIL_RANDGEN_HPP
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