Package org.apache.commons.math.random
Class BitsStreamGenerator
- java.lang.Object
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- org.apache.commons.math.random.BitsStreamGenerator
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- All Implemented Interfaces:
RandomGenerator
- Direct Known Subclasses:
AbstractWell,MersenneTwister
public abstract class BitsStreamGenerator extends java.lang.Object implements RandomGenerator
Base class for random number generators that generates bits streams.- Since:
- 2.0
- Version:
- $Revision: 990655 $ $Date: 2010-08-29 23:49:40 +0200 (dim. 29 août 2010) $
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Constructor Summary
Constructors Constructor Description BitsStreamGenerator()Creates a new random number generator.
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description protected abstract intnext(int bits)Generate next pseudorandom number.booleannextBoolean()Returns the next pseudorandom, uniformly distributedbooleanvalue from this random number generator's sequence.voidnextBytes(byte[] bytes)Generates random bytes and places them into a user-supplied byte array.doublenextDouble()Returns the next pseudorandom, uniformly distributeddoublevalue between0.0and1.0from this random number generator's sequence.floatnextFloat()Returns the next pseudorandom, uniformly distributedfloatvalue between0.0and1.0from this random number generator's sequence.doublenextGaussian()Returns the next pseudorandom, Gaussian ("normally") distributeddoublevalue with mean0.0and standard deviation1.0from this random number generator's sequence.intnextInt()Returns the next pseudorandom, uniformly distributedintvalue from this random number generator's sequence.intnextInt(int n)Returns a pseudorandom, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.longnextLong()Returns the next pseudorandom, uniformly distributedlongvalue from this random number generator's sequence.abstract voidsetSeed(int seed)Sets the seed of the underlying random number generator using anintseed.abstract voidsetSeed(int[] seed)Sets the seed of the underlying random number generator using anintarray seed.abstract voidsetSeed(long seed)Sets the seed of the underlying random number generator using alongseed.
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Method Detail
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setSeed
public abstract void setSeed(int seed)
Sets the seed of the underlying random number generator using anintseed.Sequences of values generated starting with the same seeds should be identical.
- Specified by:
setSeedin interfaceRandomGenerator- Parameters:
seed- the seed value
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setSeed
public abstract void setSeed(int[] seed)
Sets the seed of the underlying random number generator using anintarray seed.Sequences of values generated starting with the same seeds should be identical.
- Specified by:
setSeedin interfaceRandomGenerator- Parameters:
seed- the seed value
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setSeed
public abstract void setSeed(long seed)
Sets the seed of the underlying random number generator using alongseed.Sequences of values generated starting with the same seeds should be identical.
- Specified by:
setSeedin interfaceRandomGenerator- Parameters:
seed- the seed value
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next
protected abstract int next(int bits)
Generate next pseudorandom number.This method is the core generation algorithm. It is used by all the public generation methods for the various primitive types
nextBoolean(),nextBytes(byte[]),nextDouble(),nextFloat(),nextGaussian(),nextInt(),next(int)andnextLong().- Parameters:
bits- number of random bits to produce- Returns:
- random bits generated
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nextBoolean
public boolean nextBoolean()
Returns the next pseudorandom, uniformly distributedbooleanvalue from this random number generator's sequence.- Specified by:
nextBooleanin interfaceRandomGenerator- Returns:
- the next pseudorandom, uniformly distributed
booleanvalue from this random number generator's sequence
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nextBytes
public void nextBytes(byte[] bytes)
Generates random bytes and places them into a user-supplied byte array. The number of random bytes produced is equal to the length of the byte array.- Specified by:
nextBytesin interfaceRandomGenerator- Parameters:
bytes- the non-null byte array in which to put the random bytes
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nextDouble
public double nextDouble()
Returns the next pseudorandom, uniformly distributeddoublevalue between0.0and1.0from this random number generator's sequence.- Specified by:
nextDoublein interfaceRandomGenerator- Returns:
- the next pseudorandom, uniformly distributed
doublevalue between0.0and1.0from this random number generator's sequence
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nextFloat
public float nextFloat()
Returns the next pseudorandom, uniformly distributedfloatvalue between0.0and1.0from this random number generator's sequence.- Specified by:
nextFloatin interfaceRandomGenerator- Returns:
- the next pseudorandom, uniformly distributed
floatvalue between0.0and1.0from this random number generator's sequence
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nextGaussian
public double nextGaussian()
Returns the next pseudorandom, Gaussian ("normally") distributeddoublevalue with mean0.0and standard deviation1.0from this random number generator's sequence.- Specified by:
nextGaussianin interfaceRandomGenerator- Returns:
- the next pseudorandom, Gaussian ("normally") distributed
doublevalue with mean0.0and standard deviation1.0from this random number generator's sequence
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nextInt
public int nextInt()
Returns the next pseudorandom, uniformly distributedintvalue from this random number generator's sequence. All 232 possible int values should be produced with (approximately) equal probability.- Specified by:
nextIntin interfaceRandomGenerator- Returns:
- the next pseudorandom, uniformly distributed
intvalue from this random number generator's sequence
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nextInt
public int nextInt(int n) throws java.lang.IllegalArgumentExceptionReturns a pseudorandom, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.- Specified by:
nextIntin interfaceRandomGenerator- Parameters:
n- the bound on the random number to be returned. Must be positive.- Returns:
- a pseudorandom, uniformly distributed int value between 0 (inclusive) and n (exclusive).
- Throws:
java.lang.IllegalArgumentException- if n is not positive.
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nextLong
public long nextLong()
Returns the next pseudorandom, uniformly distributedlongvalue from this random number generator's sequence. All 264 possible long values should be produced with (approximately) equal probability.- Specified by:
nextLongin interfaceRandomGenerator- Returns:
- the next pseudorandom, uniformly distributed
longvalue from this random number generator's sequence
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