java.io.Serializable
public class XoShiRo256StarStarRandom
extends java.util.Random
If you need to generate just floatingpoint numbers, XoShiRo256PlusRandom
is slightly faster. If you are tight on space,
you might try XoRoShiRo128StarStarRandom
.
By using the supplied jump()
method it is possible to generate nonoverlapping long sequences
for parallel computations. This class provides also a split()
method to support recursive parallel computations, in the spirit of
SplittableRandom
.
Note that this is not a secure generator.
it.unimi.dsi.util
,
RandomGenerator
,
XoShiRo256StarStarRandomGenerator
,
Serialized FormConstructor  Description 

XoShiRo256StarStarRandom() 
Creates a new generator seeded using
Util.randomSeed() . 
XoShiRo256StarStarRandom(long seed) 
Creates a new generator using a given seed.

Modifier and Type  Method  Description 

void 
jump() 
The jump function for this generator.

static void 
main(java.lang.String[] arg) 

boolean 
nextBoolean() 

void 
nextBytes(byte[] bytes) 

double 
nextDouble() 

double 
nextDoubleFast() 
Returns the next pseudorandom, uniformly distributed
double value between 0.0 and
1.0 from this random number generator's sequence,
using a fast multiplicationfree method which, however,
can provide only 52 significant bits. 
float 
nextFloat() 

int 
nextInt() 

int 
nextInt(int n) 

long 
nextLong() 

long 
nextLong(long n) 
Returns a pseudorandom uniformly distributed
long value
between 0 (inclusive) and the specified value (exclusive), drawn from
this random number generator's sequence. 
void 
setSeed(long seed) 
Sets the seed of this generator.

void 
setState(long[] state) 
Sets the state of this generator.

XoShiRo256StarStarRandom 
split() 
Returns a new instance that shares no mutable state
with this instance.

public XoShiRo256StarStarRandom()
Util.randomSeed()
.public XoShiRo256StarStarRandom(long seed)
seed
 a seed for the generator.public long nextLong()
nextLong
in class java.util.Random
public int nextInt()
nextInt
in class java.util.Random
public int nextInt(int n)
nextInt
in class java.util.Random
public long nextLong(long n)
long
value
between 0 (inclusive) and the specified value (exclusive), drawn from
this random number generator's sequence. The algorithm used to generate
the value guarantees that the result is uniform, provided that the
sequence of 64bit values produced by this generator is.n
 the positive bound on the random number to be returned.long
value between 0
(inclusive) and n
(exclusive).public double nextDouble()
nextDouble
in class java.util.Random
public double nextDoubleFast()
double
value between 0.0
and
1.0
from this random number generator's sequence,
using a fast multiplicationfree method which, however,
can provide only 52 significant bits.
This method is faster than nextDouble()
, but it
can return only dyadic rationals of the form k / 2^{−52},
instead of the standard k / 2^{−53}. Before
version 2.4.1, this was actually the standard implementation of
nextDouble()
, so you can use this method if you need to
reproduce exactly results obtained using previous versions.
The only difference between the output of this method and that of
nextDouble()
is an additional least significant bit set in half of the
returned values. For most applications, this difference is negligible.
double
value between 0.0
and 1.0
from this
random number generator's sequence, using 52 significant bits only.public float nextFloat()
nextFloat
in class java.util.Random
public boolean nextBoolean()
nextBoolean
in class java.util.Random
public void nextBytes(byte[] bytes)
nextBytes
in class java.util.Random
public void jump()
nextLong()
; it can be used to generate 2^{64}
nonoverlapping subsequences for parallel computations.public XoShiRo256StarStarRandom split()
public void setSeed(long seed)
The argument will be used to seed a SplitMix64RandomGenerator
, whose output
will in turn be used to seed this generator. This approach makes “warmup” unnecessary,
and makes the probability of starting from a state
with a large fraction of bits set to zero astronomically small.
setSeed
in class java.util.Random
seed
 a seed for this generator.public void setState(long[] state)
The internal state of the generator will be reset, and the state array filled with the provided array.
state
 an array of 2 longs; at least one must be nonzero.public static void main(java.lang.String[] arg)