Class XorShift64StarRandom
- java.lang.Object
-
- java.util.Random
-
- it.unimi.dsi.util.XorShift64StarRandom
-
- All Implemented Interfaces:
java.io.Serializable
@Deprecated public class XorShift64StarRandom extends java.util.Random
Deprecated.UseSplitMix64Random
instead.A fast, good-quality pseudorandom number generator that combines George Marsaglia's Xorshift generators (described in “Xorshift RNGs”, Journal of Statistical Software, 8:1−6, 2003) with a multiplication.- See Also:
- Serialized Form
-
-
Constructor Summary
Constructors Constructor Description XorShift64StarRandom()
Deprecated.Creates a new generator seeded usingUtil.randomSeed()
.XorShift64StarRandom(long seed)
Deprecated.Creates a new generator using a given seed.
-
Method Summary
All Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description protected int
next(int bits)
Deprecated.boolean
nextBoolean()
Deprecated.void
nextBytes(byte[] bytes)
Deprecated.double
nextDouble()
Deprecated.float
nextFloat()
Deprecated.int
nextInt()
Deprecated.int
nextInt(int n)
Deprecated.Returns a pseudorandom, approximately uniformly distributedint
value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.long
nextLong()
Deprecated.long
nextLong(long n)
Deprecated.Returns a pseudorandom uniformly distributedlong
value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.void
setSeed(long seed)
Deprecated.Sets the seed of this generator.void
setState(long state)
Deprecated.Sets the state of this generator.
-
-
-
Constructor Detail
-
XorShift64StarRandom
public XorShift64StarRandom()
Deprecated.Creates a new generator seeded usingUtil.randomSeed()
.
-
XorShift64StarRandom
public XorShift64StarRandom(long seed)
Deprecated.Creates a new generator using a given seed.- Parameters:
seed
- a nonzero seed for the generator (if zero, the generator will be seeded withLong.MIN_VALUE
).
-
-
Method Detail
-
next
protected int next(int bits)
Deprecated.- Overrides:
next
in classjava.util.Random
-
nextLong
public long nextLong()
Deprecated.- Overrides:
nextLong
in classjava.util.Random
-
nextInt
public int nextInt()
Deprecated.- Overrides:
nextInt
in classjava.util.Random
-
nextInt
public int nextInt(int n)
Deprecated.Returns a pseudorandom, approximately uniformly distributedint
value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.The hedge “approximately” is due to the fact that to be always faster than
ThreadLocalRandom
we return the upper 63 bits ofnextLong()
modulon
instead of usingRandom
's fancy algorithm (whichnextLong(long)
uses though). This choice introduces a bias: the numbers from 0 to 263 modn
are slightly more likely than the other ones. In the worst case, “more likely” means 1.00000000023 times more likely, which is in practice undetectable (actually, due to the abysmally low quality ofRandom
's generator, the result is statistically better in any case thanRandom.nextInt(int)
's) .If for some reason you need truly uniform generation, just use
nextLong(long)
.- Overrides:
nextInt
in classjava.util.Random
- Parameters:
n
- the positive bound on the random number to be returned.- Returns:
- the next pseudorandom
int
value between0
(inclusive) andn
(exclusive).
-
nextLong
public long nextLong(long n)
Deprecated.Returns a pseudorandom uniformly distributedlong
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 64-bit values produced by this generator is.- Parameters:
n
- the positive bound on the random number to be returned.- Returns:
- the next pseudorandom
long
value between0
(inclusive) andn
(exclusive).
-
nextDouble
public double nextDouble()
Deprecated.- Overrides:
nextDouble
in classjava.util.Random
-
nextFloat
public float nextFloat()
Deprecated.- Overrides:
nextFloat
in classjava.util.Random
-
nextBoolean
public boolean nextBoolean()
Deprecated.- Overrides:
nextBoolean
in classjava.util.Random
-
nextBytes
public void nextBytes(byte[] bytes)
Deprecated.- Overrides:
nextBytes
in classjava.util.Random
-
setSeed
public void setSeed(long seed)
Deprecated.Sets the seed of this generator.The seed will be passed through
HashCommon.murmurHash3(long)
. In this way, if the user passes a small value we will avoid the short irregular transient associated with states with a very small number of bits set.- Overrides:
setSeed
in classjava.util.Random
- Parameters:
seed
- a nonzero seed for this generator (if zero, the generator will be seeded withLong.MIN_VALUE
).
-
setState
public void setState(long state)
Deprecated.Sets the state of this generator.- Parameters:
state
- the new state for this generator (must be nonzero).
-
-