Class CMWC4096RNG
- java.lang.Object
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- java.util.Random
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- org.uncommons.maths.random.CMWC4096RNG
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- All Implemented Interfaces:
java.io.Serializable
,RepeatableRNG
public class CMWC4096RNG extends java.util.Random implements RepeatableRNG
A Java version of George Marsaglia's Complementary Multiply With Carry (CMWC) RNG. This is a very fast PRNG with an extremely long period (2^131104). It should be used in preference to the
MersenneTwisterRNG
when a very long period is required.One potential drawback of this RNG is that it requires significantly more seed data than the other RNGs provided by Uncommons Maths. It requires just over 16 kilobytes, which may be a problem if your are obtaining seed data from a slow or limited entropy source. In contrast, the Mersenne Twister requires only 128 bits of seed data.
NOTE: Because instances of this class require 16-kilobyte seeds, it is not possible to seed this RNG using the
Random.setSeed(long)
method inherited fromRandom
. Calls to this method will have no effect. Instead the seed must be set by a constructor.- Since:
- 1.2
- See Also:
- Serialized Form
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Constructor Summary
Constructors Constructor Description CMWC4096RNG()
Creates a new RNG and seeds it using the default seeding strategy.CMWC4096RNG(byte[] seed)
Creates an RNG and seeds it with the specified seed data.CMWC4096RNG(SeedGenerator seedGenerator)
Seed the RNG using the provided seed generation strategy.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description byte[]
getSeed()
protected int
next(int bits)
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Field Detail
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SEED_SIZE_BYTES
private static final int SEED_SIZE_BYTES
- See Also:
- Constant Field Values
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A
private static final long A
- See Also:
- Constant Field Values
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seed
private final byte[] seed
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state
private final int[] state
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carry
private int carry
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index
private int index
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lock
private final java.util.concurrent.locks.ReentrantLock lock
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Constructor Detail
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CMWC4096RNG
public CMWC4096RNG()
Creates a new RNG and seeds it using the default seeding strategy.
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CMWC4096RNG
public CMWC4096RNG(SeedGenerator seedGenerator) throws SeedException
Seed the RNG using the provided seed generation strategy.- Parameters:
seedGenerator
- The seed generation strategy that will provide the seed value for this RNG.- Throws:
SeedException
- If there is a problem generating a seed.
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CMWC4096RNG
public CMWC4096RNG(byte[] seed)
Creates an RNG and seeds it with the specified seed data.- Parameters:
seed
- The seed data used to initialise the RNG.
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Method Detail
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getSeed
public byte[] getSeed()
- Specified by:
getSeed
in interfaceRepeatableRNG
- Returns:
- The seed data used to initialise this pseudo-random number generator.
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next
protected int next(int bits)
- Overrides:
next
in classjava.util.Random
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