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.
*
* @author Paul Houle (E-mail: paul@honeylocust.com)
* @version 1.1a
*
* @see Ranecu
* @see Ranlux
* @see Ranmar
*/
public abstract class RandomSeedable extends RandomElement {
/**
*
* Return a long integer seed given a date
*
* @param d a date
* @return a long integer seed
*
*/
public static long ClockSeed(Date d)
{
return d.getTime();
};
/**
*
* Return a long integer seed calculated from the date. Equivalent to
* ClockSeed(new Date());
*
* @return a long integer seed
*
*/
public static long ClockSeed()
{
return ClockSeed(new Date());
};
};