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java.lang.Object org.apache.commons.math3.random.BitsStreamGenerator org.apache.commons.math3.random.MersenneTwister
public class MersenneTwister
This class implements a powerful pseudorandom number generator developed by Makoto Matsumoto and Takuji Nishimura during 19961997.
This generator features an extremely long period (2^{19937}1) and 623dimensional equidistribution up to 32 bits accuracy. The home page for this generator is located at http://www.math.sci.hiroshimau.ac.jp/~mmat/MT/emt.html.
This generator is described in a paper by Makoto Matsumoto and Takuji Nishimura in 1998: Mersenne Twister: A 623Dimensionally Equidistributed Uniform PseudoRandom Number Generator, ACM Transactions on Modeling and Computer Simulation, Vol. 8, No. 1, January 1998, pp 330
This class is mainly a Java port of the 20020126 version of the generator written in C by Makoto Matsumoto and Takuji Nishimura. Here is their original copyright:
Copyright (C) 1997  2002, Makoto Matsumoto and Takuji Nishimura, All rights reserved. 
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

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. 
Constructor Summary  

MersenneTwister()
Creates a new random number generator. 

MersenneTwister(int seed)
Creates a new random number generator using a single int seed. 

MersenneTwister(int[] seed)
Creates a new random number generator using an int array seed. 

MersenneTwister(long seed)
Creates a new random number generator using a single long seed. 
Method Summary  

protected int 
next(int bits)
Generate next pseudorandom number. 
void 
setSeed(int seed)
Reinitialize the generator as if just built with the given int seed. 
void 
setSeed(int[] seed)
Reinitialize the generator as if just built with the given int array seed. 
void 
setSeed(long seed)
Reinitialize the generator as if just built with the given long seed. 
Methods inherited from class org.apache.commons.math3.random.BitsStreamGenerator 

clear, nextBoolean, nextBytes, nextDouble, nextFloat, nextGaussian, nextInt, nextInt, nextLong 
Methods inherited from class java.lang.Object 

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait 
Constructor Detail 

public MersenneTwister()
The instance is initialized using the current time plus the system identity hash code of this instance as the seed.
public MersenneTwister(int seed)
seed
 the initial seed (32 bits integer)public MersenneTwister(int[] seed)
seed
 the initial seed (32 bits integers array), if null
the seed of the generator will be related to the current timepublic MersenneTwister(long seed)
seed
 the initial seed (64 bits integer)Method Detail 

public void setSeed(int seed)
The state of the generator is exactly the same as a new generator built with the same seed.
setSeed
in interface RandomGenerator
setSeed
in class BitsStreamGenerator
seed
 the initial seed (32 bits integer)public void setSeed(int[] seed)
The state of the generator is exactly the same as a new generator built with the same seed.
setSeed
in interface RandomGenerator
setSeed
in class BitsStreamGenerator
seed
 the initial seed (32 bits integers array), if null
the seed of the generator will be the current system time plus the
system identity hash code of this instancepublic void setSeed(long seed)
The state of the generator is exactly the same as a new generator built with the same seed.
setSeed
in interface RandomGenerator
setSeed
in class BitsStreamGenerator
seed
 the initial seed (64 bits integer)protected int next(int bits)
This method is the core generation algorithm. It is used by all the
public generation methods for the various primitive types BitsStreamGenerator.nextBoolean()
, BitsStreamGenerator.nextBytes(byte[])
, BitsStreamGenerator.nextDouble()
,
BitsStreamGenerator.nextFloat()
, BitsStreamGenerator.nextGaussian()
, BitsStreamGenerator.nextInt()
,
next(int)
and BitsStreamGenerator.nextLong()
.
next
in class BitsStreamGenerator
bits
 number of random bits to produce


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