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 int
next(int bits)
Generate next pseudorandom number.boolean
nextBoolean()
Returns the next pseudorandom, uniformly distributedboolean
value from this random number generator's sequence.void
nextBytes(byte[] bytes)
Generates random bytes and places them into a user-supplied byte array.double
nextDouble()
Returns the next pseudorandom, uniformly distributeddouble
value between0.0
and1.0
from this random number generator's sequence.float
nextFloat()
Returns the next pseudorandom, uniformly distributedfloat
value between0.0
and1.0
from this random number generator's sequence.double
nextGaussian()
Returns the next pseudorandom, Gaussian ("normally") distributeddouble
value with mean0.0
and standard deviation1.0
from this random number generator's sequence.int
nextInt()
Returns the next pseudorandom, uniformly distributedint
value from this random number generator's sequence.int
nextInt(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.long
nextLong()
Returns the next pseudorandom, uniformly distributedlong
value from this random number generator's sequence.abstract void
setSeed(int seed)
Sets the seed of the underlying random number generator using anint
seed.abstract void
setSeed(int[] seed)
Sets the seed of the underlying random number generator using anint
array seed.abstract void
setSeed(long seed)
Sets the seed of the underlying random number generator using along
seed.
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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 anint
seed.Sequences of values generated starting with the same seeds should be identical.
- Specified by:
setSeed
in 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 anint
array seed.Sequences of values generated starting with the same seeds should be identical.
- Specified by:
setSeed
in 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 along
seed.Sequences of values generated starting with the same seeds should be identical.
- Specified by:
setSeed
in 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 distributedboolean
value from this random number generator's sequence.- Specified by:
nextBoolean
in interfaceRandomGenerator
- Returns:
- the next pseudorandom, uniformly distributed
boolean
value 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:
nextBytes
in 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 distributeddouble
value between0.0
and1.0
from this random number generator's sequence.- Specified by:
nextDouble
in interfaceRandomGenerator
- Returns:
- the next pseudorandom, uniformly distributed
double
value between0.0
and1.0
from this random number generator's sequence
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nextFloat
public float nextFloat()
Returns the next pseudorandom, uniformly distributedfloat
value between0.0
and1.0
from this random number generator's sequence.- Specified by:
nextFloat
in interfaceRandomGenerator
- Returns:
- the next pseudorandom, uniformly distributed
float
value between0.0
and1.0
from this random number generator's sequence
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nextGaussian
public double nextGaussian()
Returns the next pseudorandom, Gaussian ("normally") distributeddouble
value with mean0.0
and standard deviation1.0
from this random number generator's sequence.- Specified by:
nextGaussian
in interfaceRandomGenerator
- Returns:
- the next pseudorandom, Gaussian ("normally") distributed
double
value with mean0.0
and standard deviation1.0
from this random number generator's sequence
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nextInt
public int nextInt()
Returns the next pseudorandom, uniformly distributedint
value from this random number generator's sequence. All 232 possible int values should be produced with (approximately) equal probability.- Specified by:
nextInt
in interfaceRandomGenerator
- Returns:
- the next pseudorandom, uniformly distributed
int
value from this random number generator's sequence
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nextInt
public int nextInt(int n) throws java.lang.IllegalArgumentException
Returns a pseudorandom, uniformly distributed int value between 0 (inclusive) and the specified value (exclusive), drawn from this random number generator's sequence.- Specified by:
nextInt
in 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 distributedlong
value from this random number generator's sequence. All 264 possible long values should be produced with (approximately) equal probability.- Specified by:
nextLong
in interfaceRandomGenerator
- Returns:
- the next pseudorandom, uniformly distributed
long
value from this random number generator's sequence
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