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Class jnt.random.LongUniformSequence

java.lang.Object
   |
   +----jnt.random.LongUniformSequence

public class LongUniformSequence

extends Object

By default the numbers are drawn from the interval [0,1). The interval can be changed using the constructor. The user may also specify an integer seed for the sequence; sequences with the same seed are identical. If no seed is specified by the user, then a seed based on the system clock is used, which should provide a new sequence on subsequent constructions. (Beware: two sequences constructed within the clock resolution -- a millisecond -- could be identical, and so providing your own seed is generally preferable.)

This class is similar to UniformSequence, except that computations are done internally with long integers. This yields sequences with much longer cycles, but roughly doubles the computation time to generate each random variate.

This class is a translation of the Fortran subroutine UNI from the NBS Core Math Library. UNI was written by James Blue, David Kahanaer and George Marsaglia.

This generator is of the lagged Fibbonacci type.

Example of use:

Print 20 random numbers on [-1,1).

int i, seed = 687346;
double left = -1.0, right = 1.0;
LongUniformSequence random; 

random = new LongUniformSequence( seed, left, right ); 

for (i=0, i<20, i++) System.out.println( random.next() );

Version:

3 December 1997

Author:

Ronald F. Boisvert, NIST

See Also:

UniformSequence

LongUniformSequence()

Initializes a sequence of uniformly distributed quasi random numbers with a seed based on the system clock.

LongUniformSequence(double, double)

Initializes a sequence of uniformly distributed quasi random numbers on a given half-open interval [left,right) with a seed based on the system clock.

LongUniformSequence(long)

Initializes a sequence of uniformly distributed quasi random numbers with a given seed.

LongUniformSequence(long, double, double)

Initializes a sequence of uniformly distributed quasi random numbers with a given seed on a given half-open interval [left,right).

next()

Returns the next random number in the sequence.

 public LongUniformSequence()

Initializes a sequence of uniformly distributed quasi random numbers with a seed based on the system clock.

 public LongUniformSequence(double left,
                            double right)

Initializes a sequence of uniformly distributed quasi random numbers on a given half-open interval [left,right) with a seed based on the system clock.

Parameters:

left - (double)
The left endpoint of the half-open interval [left,right).

right - (double)
The right endpoint of the half-open interval [left,right).

 public LongUniformSequence(long seed)

Initializes a sequence of uniformly distributed quasi random numbers with a given seed.

Parameters:

seed - (long)
The seed of the random number generator. Two sequences with the same seed will be identical.

 public LongUniformSequence(long seed,
                            double left,
                            double right)

Initializes a sequence of uniformly distributed quasi random numbers with a given seed on a given half-open interval [left,right).

Parameters:

seed - (long)
The seed of the random number generator. Two sequences with the same seed will be identical.

left - (double)
The left endpoint of the half-open interval [left,right).

right - (double)
The right endpoint of the half-open interval [left,right).

 public double next()

Returns the next random number in the sequence.

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