RandomGenerator
, RandomGenerator.JumpableGenerator
, RandomGenerator.LeapableGenerator
, RandomGenerator.StreamableGenerator
RandomGenerator
public static interface RandomGenerator.ArbitrarilyJumpableGenerator extends RandomGenerator.LeapableGenerator
Ideally, all RandomGenerator.ArbitrarilyJumpableGenerator
objects produced by iterative jumping from a single original RandomGenerator.ArbitrarilyJumpableGenerator
object are statistically independent of one another and individually uniform, provided that they do not traverse overlapping portions of the state cycle. In practice, one must settle for some approximation to independence and uniformity. In particular, a specific implementation may assume that each generator in a stream produced by the jump
() method is used to produce a number of values no larger than the jump distance specified. Implementors are advised to use algorithms whose period is at least 2127.
For many applications, it suffices to jump forward by a power of two or some small multiple of a power of two, but this power of two may not be representable as a long
value. To avoid the use of BigInteger
values as jump distances, double
values are used instead.
Methods are provided to perform a single jump operation and also to produce a stream of generators produced from the original by iterative copying and jumping of internal state. A typical strategy for a multithreaded application is to create a single RandomGenerator.ArbitrarilyJumpableGenerator
object, call its jump
() method exactly once, and then parcel out generators from the resulting stream, one to each thread. However, each generator produced also has type RandomGenerator.ArbitrarilyJumpableGenerator
; with care, different jump distances can be used to traverse the entire state cycle in various ways.
Objects that implement RandomGenerator.ArbitrarilyJumpableGenerator
are typically not cryptographically secure. Consider instead using SecureRandom
to get a cryptographically secure pseudo-random number generator for use by security-sensitive applications.
RandomGenerator.ArbitrarilyJumpableGenerator, RandomGenerator.JumpableGenerator, RandomGenerator.LeapableGenerator, RandomGenerator.SplittableGenerator, RandomGenerator.StreamableGenerator
Modifier and Type | Method | Description |
---|---|---|
RandomGenerator.ArbitrarilyJumpableGenerator |
copy() |
Returns a new generator whose internal state is an exact copy of this generator (therefore their future behavior should be identical if subjected to the same series of operations). |
default RandomGenerator.ArbitrarilyJumpableGenerator |
copyAndJump |
Copy this generator, jump this generator forward, then return the copy. |
default void |
jump() |
Alter the state of this pseudorandom number generator so as to jump forward a large, fixed distance (typically 264 or more) within its state cycle. |
void |
jump |
Alter the state of this pseudorandom number generator so as to jump forward a specified distance within its state cycle. |
void |
jumpPowerOfTwo |
Alter the state of this pseudorandom number generator so as to jump forward a distance equal to 2 logDistance within its state cycle. |
default Stream |
jumps |
Returns an effectively unlimited stream of new pseudorandom number generators, each of which implements the RandomGenerator.ArbitrarilyJumpableGenerator interface, produced by jumping copies of this generator by different integer multiples of the specified jump distance. |
default Stream |
jumps |
Returns a stream producing the given streamSize number of new pseudorandom number generators, each of which implements the RandomGenerator.ArbitrarilyJumpableGenerator interface, produced by jumping copies of this generator by different integer multiples of the specified jump distance. |
default void |
leap() |
Alter the state of this pseudorandom number generator so as to jump forward a very large, fixed distance (typically 2128 or more) within its state cycle. |
static RandomGenerator.ArbitrarilyJumpableGenerator |
of |
Returns an instance of RandomGenerator.ArbitrarilyJumpableGenerator that utilizes the name algorithm. |
doubles, doubles, doubles, doubles, ints, ints, ints, ints, isDeprecated, longs, longs, longs, longs, nextBoolean, nextBytes, nextDouble, nextDouble, nextDouble, nextExponential, nextFloat, nextFloat, nextFloat, nextGaussian, nextGaussian, nextInt, nextInt, nextInt, nextLong, nextLong, nextLong
copyAndJump, jumpDistance, jumps, jumps, rngs, rngs
copyAndLeap, leapDistance, leaps, leaps
static RandomGenerator.ArbitrarilyJumpableGenerator of(String name)
RandomGenerator.ArbitrarilyJumpableGenerator
that utilizes the name
algorithm.name
- Name of random number generator algorithm
RandomGenerator.ArbitrarilyJumpableGenerator
NullPointerException
- if name is nullIllegalArgumentException
- if the named algorithm is not foundRandomGenerator.ArbitrarilyJumpableGenerator copy()
copy
in interface RandomGenerator.JumpableGenerator
copy
in interface RandomGenerator.LeapableGenerator
void jumpPowerOfTwo(int logDistance)
logDistance
within its state cycle.logDistance
- the base-2 logarithm of the distance to jump forward within the state cycleIllegalArgumentException
- if logDistance
is 2logDistance
is greater than the period of this generatorvoid jump(double distance)
distance
- the distance to jump forward within the state cycleIllegalArgumentException
- if distance
is not greater than or equal to 0.0, or is greater than the period of this generatordefault void jump()
jumpDistance
().jump
in interface RandomGenerator.JumpableGenerator
default Stream<RandomGenerator.ArbitrarilyJumpableGenerator> jumps(double distance)
RandomGenerator.ArbitrarilyJumpableGenerator
interface, produced by jumping copies of this generator by different integer multiples of the specified jump distance.jumps
(Long.MAX_VALUE
).distance
- a distance to jump forward within the state cycleRandomGenerator
interfaceIllegalArgumentException
- if distance
is not greater than or equal to 0.0, or is greater than the period of this generatordefault Stream<RandomGenerator.ArbitrarilyJumpableGenerator> jumps(long streamSize, double distance)
streamSize
number of new pseudorandom number generators, each of which implements the RandomGenerator.ArbitrarilyJumpableGenerator
interface, produced by jumping copies of this generator by different integer multiples of the specified jump distance.streamSize
- the number of generators to generatedistance
- a distance to jump forward within the state cycleRandomGenerator
interfaceIllegalArgumentException
- if streamSize
is less than zero or if distance
is not greater than or equal to 0.0, or is greater than the period of this generatordefault void leap()
leapDistance
().leap
in interface RandomGenerator.LeapableGenerator
default RandomGenerator.ArbitrarilyJumpableGenerator copyAndJump(double distance)
distance
- a distance to jump forward within the state cycleIllegalArgumentException
- if distance
is not greater than or equal to 0.0, or is greater than the period of this generator
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https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/util/random/RandomGenerator.ArbitrarilyJumpableGenerator.html