jsat.utils.random

Class RandomUtil

java.lang.Object

jsat.utils.random.RandomUtil

public class RandomUtil
extends java.lang.Object

This class provides assorted utilities related to random number generation and use.

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.concurrent.atomic.AtomicInteger	DEFAULT_SEED If not specified, this will be the seed used for random objects used internally within JSAT. You may change this to any desired value at the start of any experiments to consistently get new experimental results.
static boolean	INCREMENT_SEEDS This controls whether or not getRandom() will cause a change in the DEFAULT_SEED each time it is called.

Method Summary

Modifier and Type	Method and Description
static java.util.Random	getLocalRandom() Returns a Random object that is local to a given thread context, allowing re-usability at lower overhead.
static java.util.Random	getRandom() Returns a new Random object that can be used.
static java.util.Random	getRandom(int seed) Returns a new Random object that can be used, initiated with the given seed.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_SEED

public static java.util.concurrent.atomic.AtomicInteger DEFAULT_SEED

If not specified, this will be the seed used for random objects used internally within JSAT.

You may change this to any desired value at the start of any experiments to consistently get new experimental results. You may also change it at any point without ill effect, but the purpose is for consistent and repeatable experiments.

INCREMENT_SEEDS

public static boolean INCREMENT_SEEDS

This controls whether or not getRandom() will cause a change in the DEFAULT_SEED each time it is called. This is the default to ensure that multiple calls to getRandom will not return an equivalent object.

Method Detail

getRandom

public static java.util.Random getRandom()

Returns a new Random object that can be used. The Random object returned is promised to be a reasonably high quality PSRND with low memory overhead that is faster to sample from than the default Java Random. Essentially, it will be better than Java's default PRNG in every way.

By default, multiple calls to this method will result in multiple, different, seeds. Controlling the base seed and its behavior can be done using DEFAULT_SEED and INCREMENT_SEEDS.

Returns:

a new random number generator to use.

getRandom

public static java.util.Random getRandom(int seed)

Returns a new Random object that can be used, initiated with the given seed. The Random object returned is promised to be a reasonably high quality PSRND with low memory overhead that is faster to sample from than the default Java Random. Essentially, it will be better than Java's default PRNG in every way.

Parameters:

seed - the seed of the PRNG, which determines the sequence generated by the returned object

Returns:

a new random number generator to use.

getLocalRandom

public static java.util.Random getLocalRandom()

Returns a Random object that is local to a given thread context, allowing re-usability at lower overhead. Once a Random object is created for a thread, it will continue to exist.

Returns:

a Random object for use