edu.cornell.lassp.houle.RngPack
Class RandomSeedable

java.lang.Object
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  +--edu.cornell.lassp.houle.RngPack.RandomElement
        |
        +--edu.cornell.lassp.houle.RngPack.RandomSeedable

Direct Known Subclasses:

Ranmar

public abstract class RandomSeedable

extends RandomElement

RandomSeedable is an abstract class that extends the RandomElement class to include the ability to automatically generate a valid long seed from the clock. Thus it provides a consistent interface for seeding interchangable generators. It is reccomended that a RandomSeedable have a constructor that takes a long for a seed. For example, if you write a generator called ReallyRandom, you want to be able to do

 long seed=ReallyRandom.ClockSeed();
 RandomSeedable e=new ReallyRandom(seed);
 

this makes it convenient to keep a copy of the seed in case you want to restart the generator with the same seed some time in the future.

If one is going to use a long to generate a smaller seed by taking Clockseed() modulus another number, we reccomend that you use a prime number; this ensures that the generator would have the maximum "period" if it were started at regular issues, for instance, by a batch job. See Ranmar for an example.

Source code is available.

See Also:

Ranecu, Ranlux, Ranmar

Fields inherited from class edu.cornell.lassp.houle.RngPack.RandomElement

BMoutput

Constructor Summary

RandomSeedable()

Method Summary

static long	ClockSeed() Return a long integer seed calculated from the date.
static long	ClockSeed(java.util.Date d) Return a long integer seed given a date

Methods inherited from class edu.cornell.lassp.houle.RngPack.RandomElement

choose, choose, gaussian, gaussian, powlaw, raw, raw, raw, uniform

Methods inherited from class java.lang.Object

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

Constructor Detail

RandomSeedable

public RandomSeedable()

Method Detail

ClockSeed

public static long ClockSeed(java.util.Date d)

Return a long integer seed given a date

Parameters:

d - a date

Returns:

a long integer seed

ClockSeed

public static long ClockSeed()

Return a long integer seed calculated from the date. Equivalent to ClockSeed(new Date());

Returns:

a long integer seed