Class AbstractXoShiRo128
- java.lang.Object
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- org.apache.commons.rng.core.BaseProvider
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- org.apache.commons.rng.core.source32.IntProvider
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- org.apache.commons.rng.core.source32.AbstractXoShiRo128
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- All Implemented Interfaces:
RandomIntSource
,JumpableUniformRandomProvider
,LongJumpableUniformRandomProvider
,RestorableUniformRandomProvider
,UniformRandomProvider
- Direct Known Subclasses:
XoShiRo128Plus
,XoShiRo128PlusPlus
,XoShiRo128StarStar
abstract class AbstractXoShiRo128 extends IntProvider implements LongJumpableUniformRandomProvider
This abstract class is a base for algorithms from the Xor-Shift-Rotate family of 32-bit generators with 128-bits of state.- Since:
- 1.3
- See Also:
- xorshiro / xoroshiro generators
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Field Summary
Fields Modifier and Type Field Description private static int[]
JUMP_COEFFICIENTS
The coefficients for the jump function.private static int[]
LONG_JUMP_COEFFICIENTS
The coefficients for the long jump function.private static int
SEED_SIZE
Size of the state vector.protected int
state0
State 0 of the generator.protected int
state1
State 1 of the generator.protected int
state2
State 2 of the generator.protected int
state3
State 3 of the generator.
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Constructor Summary
Constructors Modifier Constructor Description (package private)
AbstractXoShiRo128(int[] seed)
Creates a new instance.(package private)
AbstractXoShiRo128(int seed0, int seed1, int seed2, int seed3)
Creates a new instance using a 4 element seed.protected
AbstractXoShiRo128(AbstractXoShiRo128 source)
Creates a copy instance.
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description protected abstract AbstractXoShiRo128
copy()
Create a copy.protected byte[]
getStateInternal()
Creates a snapshot of the RNG state.UniformRandomProvider
jump()
Creates a copy of the UniformRandomProvider and then advances the state of the current instance.JumpableUniformRandomProvider
longJump()
Creates a copy of the JumpableUniformRandomProvider and then advances the state of the current instance.int
next()
Return the next random value.protected abstract int
nextOutput()
Use the current state to compute the next output from the generator.private void
performJump(int[] jumpCoefficients)
Perform the jump to advance the generator state.private void
setState(int[] state)
Copies the state from the array into the generator state.protected void
setStateInternal(byte[] s)
Resets the RNG to the givenstate
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Methods inherited from class org.apache.commons.rng.core.source32.IntProvider
nextBoolean, nextBytes, nextBytes, nextBytesFill, nextDouble, nextInt, nextLong, resetCachedState
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Methods inherited from class org.apache.commons.rng.core.BaseProvider
checkIndex, checkStateSize, composeStateInternal, extendSeed, extendSeed, fillState, fillState, restoreState, saveState, splitStateInternal, toString
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
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Methods inherited from interface org.apache.commons.rng.JumpableUniformRandomProvider
jumps, jumps
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Methods inherited from interface org.apache.commons.rng.LongJumpableUniformRandomProvider
longJumps, longJumps
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Methods inherited from interface org.apache.commons.rng.UniformRandomProvider
doubles, doubles, doubles, doubles, ints, ints, ints, ints, longs, longs, longs, longs, nextBoolean, nextBytes, nextBytes, nextDouble, nextDouble, nextDouble, nextFloat, nextFloat, nextFloat, nextInt, nextInt, nextInt, nextLong, nextLong, nextLong
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Field Detail
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SEED_SIZE
private static final int SEED_SIZE
Size of the state vector.- See Also:
- Constant Field Values
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JUMP_COEFFICIENTS
private static final int[] JUMP_COEFFICIENTS
The coefficients for the jump function.
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LONG_JUMP_COEFFICIENTS
private static final int[] LONG_JUMP_COEFFICIENTS
The coefficients for the long jump function.
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state0
protected int state0
State 0 of the generator.
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state1
protected int state1
State 1 of the generator.
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state2
protected int state2
State 2 of the generator.
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state3
protected int state3
State 3 of the generator.
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Constructor Detail
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AbstractXoShiRo128
AbstractXoShiRo128(int[] seed)
Creates a new instance.- Parameters:
seed
- Initial seed. If the length is larger than 4, only the first 4 elements will be used; if smaller, the remaining elements will be automatically set. A seed containing all zeros will create a non-functional generator.
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AbstractXoShiRo128
AbstractXoShiRo128(int seed0, int seed1, int seed2, int seed3)
Creates a new instance using a 4 element seed. A seed containing all zeros will create a non-functional generator.- Parameters:
seed0
- Initial seed element 0.seed1
- Initial seed element 1.seed2
- Initial seed element 2.seed3
- Initial seed element 3.
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AbstractXoShiRo128
protected AbstractXoShiRo128(AbstractXoShiRo128 source)
Creates a copy instance.- Parameters:
source
- Source to copy.
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Method Detail
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setState
private void setState(int[] state)
Copies the state from the array into the generator state.- Parameters:
state
- the new state
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getStateInternal
protected byte[] getStateInternal()
Creates a snapshot of the RNG state.- Overrides:
getStateInternal
in classIntProvider
- Returns:
- the internal state.
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setStateInternal
protected void setStateInternal(byte[] s)
Resets the RNG to the givenstate
.- Overrides:
setStateInternal
in classIntProvider
- Parameters:
s
- State (previously obtained by a call toBaseProvider.getStateInternal()
).- See Also:
BaseProvider.checkStateSize(byte[],int)
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next
public int next()
Return the next random value.- Specified by:
next
in interfaceRandomIntSource
- Returns:
- the next random value.
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nextOutput
protected abstract int nextOutput()
Use the current state to compute the next output from the generator. The output function shall vary with respect to different generators. This method is called fromnext()
before the current state is updated.- Returns:
- the next output
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jump
public UniformRandomProvider jump()
Creates a copy of the UniformRandomProvider and then advances the state of the current instance. The copy is returned.The current state will be advanced in a single operation by the equivalent of a number of sequential calls to a method that updates the state of the provider. The size of the jump is implementation dependent.
Repeat invocations of this method will create a series of generators that are uniformly spaced at intervals of the output sequence. Each generator provides non-overlapping output for the length of the jump for use in parallel computations.
The jump size is the equivalent of 264 calls to
nextInt()
. It can provide up to 264 non-overlapping subsequences.- Specified by:
jump
in interfaceJumpableUniformRandomProvider
- Returns:
- A copy of the current state.
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longJump
public JumpableUniformRandomProvider longJump()
Creates a copy of the JumpableUniformRandomProvider and then advances the state of the current instance. The copy is returned.The current state will be advanced in a single operation by the equivalent of a number of sequential calls to a method that updates the state of the provider. The size of the long jump is implementation dependent.
Repeat invocations of this method will create a series of generators that are uniformly spaced at intervals of the output sequence. Each generator provides non-overlapping output for the length of the long jump for use in parallel computations.
The returned copy may be jumped
m / n
times before overlap with the current instance wherem
is the long jump length andn
is the jump length of theJumpableUniformRandomProvider.jump()
method.The jump size is the equivalent of 296 calls to
nextLong()
. It can provide up to 232 non-overlapping subsequences of length 296; each subsequence can provide up to 232 non-overlapping subsequences of length 264 using thejump()
method.- Specified by:
longJump
in interfaceLongJumpableUniformRandomProvider
- Returns:
- A copy of the current state.
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copy
protected abstract AbstractXoShiRo128 copy()
Create a copy.- Returns:
- the copy
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performJump
private void performJump(int[] jumpCoefficients)
Perform the jump to advance the generator state. Resets the cached state of the generator.- Parameters:
jumpCoefficients
- Jump coefficients.
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