java.io.Serializable
public class XoRoShiRo128PlusRandom
extends java.util.Random
XoRoShiRo128StarStarRandom
or XoShiRo256PlusRandom
.
More information can be found at our PRNG page.
Warning: the constants used in this generator differ from the ones used in the 2016 version.
If you need a general PRNG, use XoRoShiRo128StarStarRandom
. If you can use more space,
you might try XoShiRo256PlusRandom
.
By using the supplied jump()
method it is possible to generate nonoverlapping long sequences
for parallel computations; longJump()
makes it possible to create several
starting points, each providing several nonoverlapping sequences, for distributed 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
,
XoRoShiRo128PlusRandomGenerator
,
Serialized FormModifier  Constructor  Description 


XoRoShiRo128PlusRandom() 
Creates a new generator seeded using
Util.randomSeed() . 

XoRoShiRo128PlusRandom(long seed) 
Creates a new generator using a given seed.

protected 
XoRoShiRo128PlusRandom(long s0,
long s1) 
Modifier and Type  Method  Description 

XoRoShiRo128PlusRandom 
copy() 
Returns a copy of this generator.

XoRoShiRo128PlusRandom 
jump() 
The jump function for this generator.

XoRoShiRo128PlusRandom 
longJump() 
The longjump 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.

XoRoShiRo128PlusRandom 
split() 
Returns a new instance that shares no mutable state
with this instance.

protected XoRoShiRo128PlusRandom(long s0, long s1)
public XoRoShiRo128PlusRandom()
Util.randomSeed()
.public XoRoShiRo128PlusRandom(long seed)
seed
 a seed for the generator.public XoRoShiRo128PlusRandom copy()
This method is particularly useful in conjunction with the jump()
method: by calling repeatedly
jump().copy()
over a generator it is possible to create several generators producing nonoverlapping sequences.
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 XoRoShiRo128PlusRandom jump()
nextLong()
; it can be used to generate 2^{64}
nonoverlapping subsequences for parallel computations.copy()
public XoRoShiRo128PlusRandom longJump()
nextLong()
; it can be used to generate 2^{32} starting points,
from each of which jump()
will generate 2^{32} nonoverlapping
subsequences for parallel distributed computations.copy()
public XoRoShiRo128PlusRandom 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)