Class XorShift1024Star
java.lang.Object
org.apache.commons.rng.core.BaseProvider
org.apache.commons.rng.core.source64.LongProvider
org.apache.commons.rng.core.source64.XorShift1024Star
- All Implemented Interfaces:
RandomLongSource
,JumpableUniformRandomProvider
,RestorableUniformRandomProvider
,UniformRandomProvider
- Direct Known Subclasses:
XorShift1024StarPhi
A fast RNG implementing the
XorShift1024*
algorithm.
Note: This has been superseded by XorShift1024StarPhi
. The sequences emitted
by both generators are correlated.
- Since:
- 1.0
- See Also:
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate int
Index in "state" array.private static final long[]
The coefficients for the jump function.private final long
The multiplier for the XorShift1024 algorithm.private static final int
Size of the state vector.private final long[]
State. -
Constructor Summary
ConstructorsModifierConstructorDescriptionXorShift1024Star
(long[] seed) Creates a new instance.protected
XorShift1024Star
(long[] seed, long multiplier) Creates a new instance.protected
XorShift1024Star
(XorShift1024Star source) Creates a copy instance. -
Method Summary
Modifier and TypeMethodDescriptionprotected XorShift1024Star
copy()
Create a copy.protected byte[]
Creates a snapshot of the RNG state.jump()
Creates a copy of the UniformRandomProvider and then advances the state of the current instance.long
next()
Return the next random value.private void
Perform the jump to advance the generator state.private void
setSeedInternal
(long[] seed) Seeds the RNG.protected void
setStateInternal
(byte[] s) Resets the RNG to the givenstate
.Methods inherited from class org.apache.commons.rng.core.source64.LongProvider
nextBoolean, nextInt, nextLong, resetCachedState
Methods inherited from class org.apache.commons.rng.core.BaseProvider
checkIndex, checkStateSize, composeStateInternal, extendSeed, extendSeed, fillState, fillState, restoreState, saveState, splitStateInternal, toString
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
Methods inherited from interface org.apache.commons.rng.JumpableUniformRandomProvider
jumps, jumps
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 Details
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SEED_SIZE
private static final int SEED_SIZESize of the state vector.- See Also:
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JUMP_COEFFICIENTS
private static final long[] JUMP_COEFFICIENTSThe coefficients for the jump function. -
state
private final long[] stateState. -
multiplier
private final long multiplierThe multiplier for the XorShift1024 algorithm. -
index
private int indexIndex in "state" array.
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Constructor Details
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XorShift1024Star
public XorShift1024Star(long[] seed) Creates a new instance.- Parameters:
seed
- Initial seed. If the length is larger than 16, only the first 16 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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XorShift1024Star
protected XorShift1024Star(long[] seed, long multiplier) Creates a new instance.- Parameters:
seed
- Initial seed. If the length is larger than 16, only the first 16 elements will be used; if smaller, the remaining elements will be automatically set. A seed containing all zeros will create a non-functional generator.multiplier
- The multiplier for the XorShift1024 algorithm.- Since:
- 1.3
-
XorShift1024Star
Creates a copy instance.- Parameters:
source
- Source to copy.- Since:
- 1.3
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Method Details
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getStateInternal
protected byte[] getStateInternal()Creates a snapshot of the RNG state.- Overrides:
getStateInternal
in classLongProvider
- Returns:
- the internal state.
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setStateInternal
protected void setStateInternal(byte[] s) Resets the RNG to the givenstate
.- Overrides:
setStateInternal
in classLongProvider
- Parameters:
s
- State (previously obtained by a call toBaseProvider.getStateInternal()
).- See Also:
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setSeedInternal
private void setSeedInternal(long[] seed) Seeds the RNG.- Parameters:
seed
- Seed.
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next
public long next()Return the next random value.- Specified by:
next
in interfaceRandomLongSource
- Returns:
- the next random value.
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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 2512 calls to
nextLong()
. It can provide up to 2512 non-overlapping subsequences.- Specified by:
jump
in interfaceJumpableUniformRandomProvider
- Returns:
- A copy of the current state.
- Since:
- 1.3
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copy
Create a copy.- Returns:
- the copy
- Since:
- 1.3
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performJump
private void performJump()Perform the jump to advance the generator state. Resets the cached state of the generator.
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