java.lang.Object

org.hipparchus.random.RandomDataGenerator

All Implemented Interfaces:: Serializable, RandomGenerator

public class RandomDataGenerator extends Object implements RandomGenerator, Serializable

A class for generating random data.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor

Description

RandomDataGenerator()

Construct a RandomDataGenerator with a default RandomGenerator as its source of random data.

RandomDataGenerator(long seed)

Construct a RandomDataGenerator with a default RandomGenerator as its source of random data, initialized with the given seed value.
Method Summary

Modifier and Type

Method

Description

protected RandomGenerator

delegate()

Returns the backing delegate instance that methods are forwarded to.

double

nextBeta(double alpha, double beta)

Returns the next pseudo-random beta-distributed value with the given shape and scale parameters.

boolean

nextBoolean()

Returns the next pseudorandom, uniformly distributed boolean value from this random number generator's sequence.

void

nextBytes(byte[] bytes)

Generates random bytes and places them into a user-supplied byte array.

void

nextBytes(byte[] bytes, int offset, int length)

Generates random bytes and places them into a user-supplied byte array.

int

nextDeviate(IntegerDistribution dist)

Returns a random deviate from the given distribution.

double

nextDeviate(RealDistribution dist)

Returns a random deviate from the given distribution.

int[]

nextDeviates(IntegerDistribution dist, int size)

Returns an array of random deviates from the given distribution.

double[]

nextDeviates(RealDistribution dist, int size)

Returns an array of random deviates from the given distribution.

double

nextDouble()

Returns the next pseudorandom, uniformly distributed double value between 0.0 and 1.0 from this random number generator's sequence.

double

nextExponential(double mean)

Returns the next pseudo-random, exponentially distributed deviate.

float

nextFloat()

Returns the next pseudorandom, uniformly distributed float value between 0.0 and 1.0 from this random number generator's sequence.

double

nextGamma(double shape, double scale)

Returns the next pseudo-random gamma-distributed value with the given shape and scale parameters.

double

nextGaussian()

Returns the next pseudorandom, Gaussian ("normally") distributed double value with mean 0.0 and standard deviation 1.0 from this random number generator's sequence.

String

nextHexString(int len)

Generates a random string of hex characters of length len.

int

nextInt()

Returns the next pseudorandom, uniformly distributed int 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.

int

nextInt(int lower, int upper)

Returns a uniformly distributed random integer between lower and upper (inclusive).

double

nextLogNormal(double shape, double scale)

Returns the next log-normally-distributed pseudo-random deviate.

long

nextLong()

Returns the next pseudorandom, uniformly distributed long value from this random number generator's sequence.

long

nextLong(long 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(long lower, long upper)

Returns a uniformly distributed random long integer between lower and upper (inclusive).

double

nextNormal(double mean, double standardDeviation)

Returns the next normally-distributed pseudo-random deviate.

int[]

nextPermutation(int n, int k)

Generates an integer array of length k whose entries are selected randomly, without repetition, from the integers 0, ..., n - 1 (inclusive).

int

nextPoisson(double mean)

Returns a poisson-distributed deviate with the given mean.

double[]

nextSample(double[] a, int k)

Returns an array of k double values selected randomly from the double array a.

Object[]

nextSample(Collection<?> c, int k)

Returns an array of k objects selected randomly from the Collection c.

int[]

nextSampleWithReplacement(int sampleSize, double[] weights)

Generates a random sample of size sampleSize from {0, 1, ...

double

nextUniform(double lower, double upper)

Returns a double value uniformly distributed over [lower, upper]

int

nextZipf(int numberOfElements, double exponent)

Returns an integer value following a Zipf distribution with the given parameter.

static RandomDataGenerator

of(RandomGenerator randomGenerator)

Factory method to create a RandomData instance using the supplied RandomGenerator.

void

setSeed(int seed)

Sets the seed of the underlying random number generator using an int seed.

void

setSeed(int[] seed)

Sets the seed of the underlying random number generator using an int array seed.

void

setSeed(long seed)

Sets the seed of the underlying random number generator using a long seed.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.hipparchus.random.RandomGenerator
nextBoolean, nextBytes, nextBytes, nextDouble, nextFloat, nextGaussian, nextInt, nextInt, nextLong, nextLong, setSeed, setSeed, setSeed

Constructor Details
- RandomDataGenerator
  
  public RandomDataGenerator()
  
  Construct a RandomDataGenerator with a default RandomGenerator as its source of random data.
- RandomDataGenerator
  
  public RandomDataGenerator(long seed)
  
  Construct a RandomDataGenerator with a default RandomGenerator as its source of random data, initialized with the given seed value.
  
  Parameters:
  
  seed - seed value
Method Details
- of
  
  public static RandomDataGenerator of(RandomGenerator randomGenerator)
  
  Factory method to create a RandomData instance using the supplied RandomGenerator.
  
  Parameters:
  
  randomGenerator - source of random bits
  
  Returns:
  
  a RandomData using the given RandomGenerator to source bits
  
  Throws:
  
  MathIllegalArgumentException - if randomGenerator is null
- delegate
  
  protected RandomGenerator delegate()
  
  Returns the backing delegate instance that methods are forwarded to.
  Concrete subclasses override this method to supply the instance being decorated.
  
  Returns:
  
  the delegate instance
- nextBeta
  
  public double nextBeta(double alpha, double beta)
  
  Returns the next pseudo-random beta-distributed value with the given shape and scale parameters.
  
  Parameters:
  
  alpha - First shape parameter (must be positive).
  
  beta - Second shape parameter (must be positive).
  
  Returns:
  
  beta-distributed random deviate
- nextExponential
  
  public double nextExponential(double mean)
  
  Returns the next pseudo-random, exponentially distributed deviate.
  
  Parameters:
  
  mean - mean of the exponential distribution
  
  Returns:
  
  exponentially distributed deviate about the given mean
- nextGamma
  
  public double nextGamma(double shape, double scale)
  
  Returns the next pseudo-random gamma-distributed value with the given shape and scale parameters.
  
  Parameters:
  
  shape - shape parameter of the distribution
  
  scale - scale parameter of the distribution
  
  Returns:
  
  gamma-distributed random deviate
- nextNormal
  
  public double nextNormal(double mean, double standardDeviation)
  
  Returns the next normally-distributed pseudo-random deviate.
  
  Parameters:
  
  mean - mean of the normal distribution
  
  standardDeviation - standard deviation of the normal distribution
  
  Returns:
  
  a random value, normally distributed with the given mean and standard deviation
- nextLogNormal
  
  public double nextLogNormal(double shape, double scale)
  
  Returns the next log-normally-distributed pseudo-random deviate.
  
  Parameters:
  
  shape - shape parameter of the log-normal distribution
  
  scale - scale parameter of the log-normal distribution
  
  Returns:
  
  a random value, normally distributed with the given mean and standard deviation
- nextPoisson
  
  public int nextPoisson(double mean)
  
  Returns a poisson-distributed deviate with the given mean.
  
  Parameters:
  
  mean - expected value
  
  Returns:
  
  poisson deviate
  
  Throws:
  
  MathIllegalArgumentException - if mean is not strictly positive
- nextDeviate
  
  public double nextDeviate(RealDistribution dist)
  
  Returns a random deviate from the given distribution.
  
  Parameters:
  
  dist - the distribution to sample from
  
  Returns:
  
  a random value following the given distribution
- nextDeviates
  
  public double[] nextDeviates(RealDistribution dist, int size)
  
  Returns an array of random deviates from the given distribution.
  
  Parameters:
  
  dist - the distribution to sample from
  
  size - the number of values to return
  
  Returns:
  
  an array of size values following the given distribution
- nextDeviate
  
  public int nextDeviate(IntegerDistribution dist)
  
  Returns a random deviate from the given distribution.
  
  Parameters:
  
  dist - the distribution to sample from
  
  Returns:
  
  a random value following the given distribution
- nextDeviates
  
  public int[] nextDeviates(IntegerDistribution dist, int size)
  
  Returns an array of random deviates from the given distribution.
  
  Parameters:
  
  dist - the distribution to sample from
  
  size - the number of values to return
  
  Returns:
  
  an array of size values following the given distribution
- nextInt
  
  public int nextInt(int lower, int upper)
  
  Returns a uniformly distributed random integer between lower and upper (inclusive).
  
  Parameters:
  
  lower - lower bound for the generated value
  
  upper - upper bound for the generated value
  
  Returns:
  
  a random integer value within the given bounds
  
  Throws:
  
  MathIllegalArgumentException - if lower is not strictly less than or equal to upper
- nextLong
  
  public long nextLong(long lower, long upper) throws MathIllegalArgumentException
  
  Returns a uniformly distributed random long integer between lower and upper (inclusive).
  
  Parameters:
  
  lower - lower bound for the generated value
  
  upper - upper bound for the generated value
  
  Returns:
  
  a random long integer value within the given bounds
  
  Throws:
  
  MathIllegalArgumentException - if lower is not strictly less than or equal to upper
- nextUniform
  
  public double nextUniform(double lower, double upper)
  
  Returns a double value uniformly distributed over [lower, upper]
  
  Parameters:
  
  lower - lower bound
  
  upper - upper bound
  
  Returns:
  
  uniform deviate
  
  Throws:
  
  MathIllegalArgumentException - if upper is less than or equal to upper
- nextZipf
  
  public int nextZipf(int numberOfElements, double exponent)
  
  Returns an integer value following a Zipf distribution with the given parameter.
  
  Parameters:
  
  numberOfElements - number of elements of the distribution
  
  exponent - exponent of the distribution
  
  Returns:
  
  random Zipf value
- nextHexString
  
  public String nextHexString(int len) throws MathIllegalArgumentException
  Generates a random string of hex characters of length len.
  The generated string will be random, but not cryptographically secure.
  Algorithm Description: hex strings are generated using a 2-step process.
  
  len / 2 + 1 binary bytes are generated using the underlying Random
  
  Each binary byte is translated into 2 hex digits
  Parameters:
  
  len - the desired string length.
  
  Returns:
  
  the random string.
  
  Throws:
  
  MathIllegalArgumentException - if len <= 0.
- nextPermutation
  
  public int[] nextPermutation(int n, int k) throws MathIllegalArgumentException
  
  Generates an integer array of length k whose entries are selected randomly, without repetition, from the integers 0, ..., n - 1 (inclusive).
  Generated arrays represent permutations of n taken k at a time.
  This method calls MathArrays.shuffle in order to create a random shuffle of the set of natural numbers { 0, 1, ..., n - 1 }.
  
  Parameters:
  
  n - the domain of the permutation
  
  k - the size of the permutation
  
  Returns:
  
  a random k-permutation of n, as an array of integers
  
  Throws:
  
  MathIllegalArgumentException - if k > n.
  
  MathIllegalArgumentException - if k <= 0.
- nextSample
  
  public Object[] nextSample(Collection<?> c, int k) throws MathIllegalArgumentException
  
  Returns an array of k objects selected randomly from the Collection c.
  Sampling from c is without replacement; but if c contains identical objects, the sample may include repeats. If all elements of c are distinct, the resulting object array represents a Simple Random Sample of size k from the elements of c.
  
  This method calls nextPermutation(c.size(), k) in order to sample the collection.
  
  Parameters:
  
  c - the collection to be sampled
  
  k - the size of the sample
  
  Returns:
  
  a random sample of k elements from c
  
  Throws:
  
  MathIllegalArgumentException - if k > c.size().
  
  MathIllegalArgumentException - if k <= 0.
- nextSample
  
  public double[] nextSample(double[] a, int k) throws MathIllegalArgumentException
  
  Returns an array of k double values selected randomly from the double array a.
  Sampling from a is without replacement; but if a contains identical objects, the sample may include repeats. If all elements of a are distinct, the resulting object array represents a Simple Random Sample of size k from the elements of a.
  
  Parameters:
  
  a - the array to be sampled
  
  k - the size of the sample
  
  Returns:
  
  a random sample of k elements from a
  
  Throws:
  
  MathIllegalArgumentException - if k > c.size().
  
  MathIllegalArgumentException - if k <= 0.
- nextSampleWithReplacement
  
  public int[] nextSampleWithReplacement(int sampleSize, double[] weights)
  
  Generates a random sample of size sampleSize from {0, 1, ... , weights.length - 1}, using weights as probabilities.
  For 0 < i < weights.length, the probability that i is selected (on any draw) is weights[i]. If necessary, the weights array is normalized to sum to 1 so that weights[i] is a probability and the array sums to 1.
  Weights can be 0, but must not be negative, infinite or NaN. At least one weight must be positive.
  
  Parameters:
  
  sampleSize - size of sample to generate
  
  weights - probability sampling weights
  
  Returns:
  
  an array of integers between 0 and weights.length - 1
  
  Throws:
  
  MathIllegalArgumentException - if weights contains negative, NaN or infinite values or only 0s or sampleSize is less than 0
- setSeed
  
  public void setSeed(int seed)
  
  Sets the seed of the underlying random number generator using an int seed.
  Sequences of values generated starting with the same seeds should be identical.
  
  Specified by:
  
  setSeed in interface RandomGenerator
  
  Parameters:
  
  seed - the seed value
- setSeed
  
  public void setSeed(int[] seed)
  
  Sets the seed of the underlying random number generator using an int array seed.
  Sequences of values generated starting with the same seeds should be identical.
  
  Specified by:
  
  setSeed in interface RandomGenerator
  
  Parameters:
  
  seed - the seed value
- setSeed
  
  public void setSeed(long seed)
  
  Sets the seed of the underlying random number generator using a long seed.
  Sequences of values generated starting with the same seeds should be identical.
  
  Specified by:
  
  setSeed in interface RandomGenerator
  
  Parameters:
  
  seed - the seed value
- 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 interface RandomGenerator
  
  Parameters:
  
  bytes - the non-null byte array in which to put the random bytes
- nextBytes
  
  public void nextBytes(byte[] bytes, int offset, int length)
  
  Generates random bytes and places them into a user-supplied byte array.
  
  Specified by:
  
  nextBytes in interface RandomGenerator
  
  Parameters:
  
  bytes - the non-null byte array in which to put the random bytes
  
  offset - the starting index for inserting the generated bytes into the array
  
  length - the number of bytes to generate
- nextInt
  
  public int nextInt()
  
  Returns the next pseudorandom, uniformly distributed int value from this random number generator's sequence.
  All 2³² possible int values should be produced with (approximately) equal probability.
  
  Specified by:
  
  nextInt in interface RandomGenerator
  
  Returns:
  
  the next pseudorandom, uniformly distributed int value from this random number generator's sequence
- nextInt
  
  public 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.
  
  Specified by:
  
  nextInt in interface RandomGenerator
  
  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).
- nextLong
  
  public long nextLong()
  
  Returns the next pseudorandom, uniformly distributed long value from this random number generator's sequence. All 2⁶⁴ possible long values should be produced with (approximately) equal probability.
  
  Specified by:
  
  nextLong in interface RandomGenerator
  
  Returns:
  
  the next pseudorandom, uniformly distributed long value from this random number generator's sequence
- nextLong
  
  public long nextLong(long n)
  
  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:
  
  nextLong in interface RandomGenerator
  
  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).
- nextBoolean
  
  public boolean nextBoolean()
  
  Returns the next pseudorandom, uniformly distributed boolean value from this random number generator's sequence.
  
  Specified by:
  
  nextBoolean in interface RandomGenerator
  
  Returns:
  
  the next pseudorandom, uniformly distributed boolean value from this random number generator's sequence
- nextFloat
  
  public float nextFloat()
  
  Returns the next pseudorandom, uniformly distributed float value between 0.0 and 1.0 from this random number generator's sequence.
  
  Specified by:
  
  nextFloat in interface RandomGenerator
  
  Returns:
  
  the next pseudorandom, uniformly distributed float value between 0.0 and 1.0 from this random number generator's sequence
- nextDouble
  
  public double nextDouble()
  
  Returns the next pseudorandom, uniformly distributed double value between 0.0 and 1.0 from this random number generator's sequence.
  
  Specified by:
  
  nextDouble in interface RandomGenerator
  
  Returns:
  
  the next pseudorandom, uniformly distributed double value between 0.0 and 1.0 from this random number generator's sequence
- nextGaussian
  
  public double nextGaussian()
  
  Returns the next pseudorandom, Gaussian ("normally") distributed double value with mean 0.0 and standard deviation 1.0 from this random number generator's sequence.
  
  Specified by:
  
  nextGaussian in interface RandomGenerator
  
  Returns:
  
  the next pseudorandom, Gaussian ("normally") distributed double value with mean 0.0 and standard deviation 1.0 from this random number generator's sequence

Class RandomDataGenerator

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface org.hipparchus.random.RandomGenerator

Constructor Details

RandomDataGenerator

RandomDataGenerator

Method Details

of

delegate

nextBeta

nextExponential

nextGamma

nextNormal

nextLogNormal

nextPoisson

nextDeviate

nextDeviates

nextDeviate

nextDeviates

nextInt

nextLong

nextUniform

nextZipf

nextHexString

nextPermutation

nextSample

nextSample

nextSampleWithReplacement

setSeed

setSeed

setSeed

nextBytes

nextBytes

nextInt

nextInt

nextLong

nextLong

nextBoolean

nextFloat

nextDouble

nextGaussian