umontreal.iro.lecuyer.rng
Class WELL607

java.lang.Object
  umontreal.iro.lecuyer.rng.RandomStreamBase
      umontreal.iro.lecuyer.rng.WELL607

All Implemented Interfaces:

Serializable, Cloneable, CloneableRandomStream, RandomStream

public class WELL607
extends RandomStreamBase

This class implements the RandomStream interface via inheritance from RandomStreamBase. The backbone generator is a Well Equidistributed Long period Linear Random Number Generator (WELL), proposed by F. Panneton. The implemented generator is the WELL607, which has a state size of 607 bits and a period length of approximatively 2⁶⁰⁷. The values of V, W and Z are 2¹⁵⁰, 2²⁵⁰ and 2⁴⁰⁰ respectively (see RandomStream for their definition). The seed of the RNG, and the state of a stream at any given step, is a 19-dimensional vector of 32-bit integers. The output of nextValue has 32 bits of precision.

See Also:

Serialized Form

Constructor Summary

WELL607()
Constructs a new stream.

WELL607(String name)
Constructs a new stream with the identifier name (used in the toString method).

Method Summary

WELL607	clone() Clones the current generator and return its copy.
int[]	getState() Returns the current state of the stream, represented as an array of 19 integers.
void	resetNextSubstream() Reinitializes the stream to the beginning of its next substream: Ng is computed, and Cg and Bg are set to Ng.
void	resetStartStream() Reinitializes the stream to its initial state Ig: Cg and Bg are set to Ig.
void	resetStartSubstream() Reinitializes the stream to the beginning of its current substream: Cg is set to Bg.
static void	setPackageSeed(int[] seed) Sets the initial seed of the class WELL607 to the 19 integers of the vector seed[0..18].
void	setSeed(int[] seed) This method is discouraged for normal use.
String	toString() Returns a string containing the current state of this stream.

Methods inherited from class umontreal.iro.lecuyer.rng.RandomStreamBase

formatState, formatStateFull, increasedPrecision, nextArrayOfDouble, nextArrayOfInt, nextDouble, nextInt

Methods inherited from class java.lang.Object

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

Constructor Detail

WELL607

public WELL607()

Constructs a new stream.

WELL607

public WELL607(String name)

Constructs a new stream with the identifier name (used in the toString method).

Parameters:

name - name of the stream

Method Detail

setPackageSeed

public static void setPackageSeed(int[] seed)

Sets the initial seed of the class WELL607 to the 19 integers of the vector seed[0..18]. This will be the initial seed of the next created stream. At least one of the integers must not be zero and if this integer is the last one, it must not be equal to 0x80000000.

Parameters:

seed - array of 19 elements representing the seed

setSeed

public void setSeed(int[] seed)

This method is discouraged for normal use. Initializes the stream at the beginning of a stream with the initial seed seed[0..18]. The seed must satisfy the same conditions as in setPackageSeed. This method only affects the specified stream; the others are not modified. Hence after calling this method, the beginning of the streams will no longer be spaced Z values apart. For this reason, this method should only be used in very exceptional cases; proper use of the reset... methods and of the stream constructor is preferable.

Parameters:

seed - array of 19 elements representing the seed

getState

public int[] getState()

Returns the current state of the stream, represented as an array of 19 integers.

Returns:

the current state of the stream

resetStartStream

public void resetStartStream()

Description copied from interface: RandomStream

Reinitializes the stream to its initial state I_g: C_g and B_g are set to I_g.

Specified by:

resetStartStream in interface RandomStream

Specified by:

resetStartStream in class RandomStreamBase

resetStartSubstream

public void resetStartSubstream()

Description copied from interface: RandomStream

Reinitializes the stream to the beginning of its current substream: C_g is set to B_g.

Specified by:

resetStartSubstream in interface RandomStream

Specified by:

resetStartSubstream in class RandomStreamBase

resetNextSubstream

public void resetNextSubstream()

Description copied from interface: RandomStream

Reinitializes the stream to the beginning of its next substream: N_g is computed, and C_g and B_g are set to N_g.

Specified by:

resetNextSubstream in interface RandomStream

Specified by:

resetNextSubstream in class RandomStreamBase

toString

public String toString()

Description copied from interface: RandomStream

Returns a string containing the current state of this stream.

Specified by:

toString in interface RandomStream

Specified by:

toString in class RandomStreamBase

Returns:

the state of the generator formated as a string

clone

public WELL607 clone()

Clones the current generator and return its copy.

Specified by:

clone in interface CloneableRandomStream

Returns:

A deep copy of the current generator