desmoj.core.dist

Class MersenneTwisterRandomGenerator

java.lang.Object

desmoj.core.dist.MersenneTwisterRandomGenerator

All Implemented Interfaces:

UniformRandomGenerator

public class MersenneTwisterRandomGenerator
extends java.lang.Object
implements UniformRandomGenerator

Mersenne twister uniform pseudo random generator configured such that a stream of [0,1] double values is produced. Implements the desmoj.dist.UniformRandomGenerator interface. The algorithm for pseudo random number generation is based on the Mersenne twister variant MT19937 and has a period of 2¹⁹⁹³⁷ - 1; see the Mersenne twister wikipedia entry for details.

Version:

DESMO-J, Ver. 2.5.1c copyright (c) 2015

Author:

Tim Lechler, Johannes Göbel Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

See Also:

UniformRandomGenerator, Distribution, Random

Constructor Summary

Constructors

Constructor and Description
MersenneTwisterRandomGenerator() Creates a MersenneTwisterRandomGenerator with seed 42.
MersenneTwisterRandomGenerator(long seed) Creates a MersenneTwisterRandomGenerator with given value as initial seed.

Method Summary

Modifier and Type	Method and Description
double	nextDouble() Returns the next pseudo random uniform [0,1] distributed double value from the stream produced by the underlying pseudo random number generator.
int	nextInt(int bits) Returns the next pseudo random integer of a given bit length.
long	nextLong() Returns the next pseudo random uniform distributed long value from the stream produced by the underlying pseudo random number generator.
void	setSeed(long newSeed) Sets the seed for the pseudo random number generator.
void	twistNumbers() Internal procedure to create ("twist") 624 new pseudo random numbers based on the last 624 pseudo random numbers.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MersenneTwisterRandomGenerator

public MersenneTwisterRandomGenerator()

Creates a MersenneTwisterRandomGenerator with seed 42. The value 42 has been taken by pure coincidence. It is not really related to Douglas Adams' "Hitchhikers Guide to the Galaxy" trilogy of five books (so far).

MersenneTwisterRandomGenerator

public MersenneTwisterRandomGenerator(long seed)

Creates a MersenneTwisterRandomGenerator with given value as initial seed.

Parameters:

seed - long : The initial seed of the underlying pseudo random generator

Method Detail

nextDouble

public double nextDouble()

Returns the next pseudo random uniform [0,1] distributed double value from the stream produced by the underlying pseudo random number generator.

Specified by:

nextDouble in interface UniformRandomGenerator

Returns:

double : The next pseudo random uniform [0,1] distributed double value

nextLong

public long nextLong()

Returns the next pseudo random uniform distributed long value from the stream produced by the underlying pseudo random number generator.

nextInt

public int nextInt(int bits)

Returns the next pseudo random integer of a given bit length.

Parameters:

bits - int : Bit length of the integer to be returned

Returns:

double : The next pseudo random integer of a given bit length

twistNumbers

public void twistNumbers()

Internal procedure to create ("twist") 624 new pseudo random numbers based on the last 624 pseudo random numbers.

setSeed

public void setSeed(long newSeed)

Sets the seed for the pseudo random number generator.

Specified by:

setSeed in interface UniformRandomGenerator

Parameters:

newSeed - long : The new initial seed value for the pseudo random number generator