Package cern.jet.random.engine
Class DRand
- java.lang.Object
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- cern.colt.PersistentObject
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- cern.jet.random.engine.RandomEngine
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- cern.jet.random.engine.DRand
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- All Implemented Interfaces:
DoubleFunction
,IntFunction
,java.io.Serializable
,java.lang.Cloneable
public class DRand extends RandomEngine
Quick medium quality uniform pseudo-random number generator. Produces uniformly distributed int's and long's in the closed intervals [Integer.MIN_VALUE,Integer.MAX_VALUE] and [Long.MIN_VALUE,Long.MAX_VALUE], respectively, as well as float's and double's in the open unit intervals (0.0f,1.0f) and (0.0,1.0), respectively.The seed can be any integer satisfying 0 < 4*seed+1 < 232. In other words, there must hold seed >= 0 && seed < 1073741823.
Quality: This generator follows the multiplicative congruential method of the form
- z(i+1) = a * z(i) (mod m) with a=663608941 (=0X278DDE6DL), m=232.
- z(i) assumes all different values 0 < 4*seed+1 < m during a full period of 230.
Performance: TO_DO
Implementation: TO_DO
Note that this implementation is not synchronized.
- Version:
- 1.0, 09/24/99
- See Also:
MersenneTwister
,Random
, Serialized Form
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Field Summary
Fields Modifier and Type Field Description private int
current
static int
DEFAULT_SEED
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Fields inherited from class cern.colt.PersistentObject
serialVersionUID
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Constructor Summary
Constructors Constructor Description DRand()
Constructs and returns a random number generator with a default seed, which is a constant.DRand(int seed)
Constructs and returns a random number generator with the given seed.DRand(java.util.Date d)
Constructs and returns a random number generator seeded with the given date.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description int
nextInt()
Returns a 32 bit uniformly distributed random number in the closed interval [Integer.MIN_VALUE,Integer.MAX_VALUE] (including Integer.MIN_VALUE and Integer.MAX_VALUE).protected void
setSeed(int seed)
Sets the receiver's seed.-
Methods inherited from class cern.jet.random.engine.RandomEngine
apply, apply, makeDefault, nextDouble, nextFloat, nextLong, raw
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Methods inherited from class cern.colt.PersistentObject
clone
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Field Detail
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current
private int current
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DEFAULT_SEED
public static final int DEFAULT_SEED
- See Also:
- Constant Field Values
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Constructor Detail
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DRand
public DRand()
Constructs and returns a random number generator with a default seed, which is a constant.
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DRand
public DRand(int seed)
Constructs and returns a random number generator with the given seed.- Parameters:
seed
- should not be 0, in such a case DRand.DEFAULT_SEED is substituted.
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DRand
public DRand(java.util.Date d)
Constructs and returns a random number generator seeded with the given date.- Parameters:
d
- typically new java.util.Date()
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Method Detail
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nextInt
public int nextInt()
Returns a 32 bit uniformly distributed random number in the closed interval [Integer.MIN_VALUE,Integer.MAX_VALUE] (including Integer.MIN_VALUE and Integer.MAX_VALUE).- Specified by:
nextInt
in classRandomEngine
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setSeed
protected void setSeed(int seed)
Sets the receiver's seed. This method resets the receiver's entire internal state. The following condition must hold: seed >= 0 && seed < (232-1) / 4.- Parameters:
seed
- if the above condition does not hold, a modified seed that meets the condition is silently substituted.
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