org.apache.commons.math3.random

## Interface RandomData

• ### Method Summary

Methods
Modifier and Type Method and Description
double nextExponential(double mean)
Deprecated.
Generates a random value from the exponential distribution with specified mean.
double nextGaussian(double mu, double sigma)
Deprecated.
Generates a random value from the Normal (or Gaussian) distribution with specified mean and standard deviation.
String nextHexString(int len)
Deprecated.
Generates a random string of hex characters of length len.
int nextInt(int lower, int upper)
Deprecated.
Generates a uniformly distributed random integer between lower and upper (endpoints included).
long nextLong(long lower, long upper)
Deprecated.
Generates a uniformly distributed random long integer between lower and upper (endpoints included).
int[] nextPermutation(int n, int k)
Deprecated.
Generates an integer array of length k whose entries are selected randomly, without repetition, from the integers 0, ..., n - 1 (inclusive).
long nextPoisson(double mean)
Deprecated.
Generates a random value from the Poisson distribution with the given mean.
Object[] nextSample(Collection<?> c, int k)
Deprecated.
Returns an array of k objects selected randomly from the Collection c.
String nextSecureHexString(int len)
Deprecated.
Generates a random string of hex characters from a secure random sequence.
int nextSecureInt(int lower, int upper)
Deprecated.
Generates a uniformly distributed random integer between lower and upper (endpoints included) from a secure random sequence.
long nextSecureLong(long lower, long upper)
Deprecated.
Generates a uniformly distributed random long integer between lower and upper (endpoints included) from a secure random sequence.
double nextUniform(double lower, double upper)
Deprecated.
Generates a uniformly distributed random value from the open interval (lower, upper) (i.e., endpoints excluded).
double nextUniform(double lower, double upper, boolean lowerInclusive)
Deprecated.
Generates a uniformly distributed random value from the interval (lower, upper) or the interval [lower, upper).
• ### Method Detail

• #### nextHexString

String nextHexString(int len)
throws NotStrictlyPositiveException
Deprecated.
Generates a random string of hex characters of length len.

The generated string will be random, but not cryptographically secure. To generate cryptographically secure strings, use nextSecureHexString(int).

Parameters:
len - the length of the string to be generated
Returns:
a random string of hex characters of length len
Throws:
NotStrictlyPositiveException - if len <= 0
• #### nextInt

int nextInt(int lower,
int upper)
throws NumberIsTooLargeException
Deprecated.
Generates a uniformly distributed random integer between lower and upper (endpoints included).

The generated integer will be random, but not cryptographically secure. To generate cryptographically secure integer sequences, use nextSecureInt(int, int).

Parameters:
lower - lower bound for generated integer
upper - upper bound for generated integer
Returns:
a random integer greater than or equal to lower and less than or equal to upper
Throws:
NumberIsTooLargeException - if lower >= upper
• #### nextLong

long nextLong(long lower,
long upper)
throws NumberIsTooLargeException
Deprecated.
Generates a uniformly distributed random long integer between lower and upper (endpoints included).

The generated long integer values will be random, but not cryptographically secure. To generate cryptographically secure sequences of longs, use nextSecureLong(long, long).

Parameters:
lower - lower bound for generated long integer
upper - upper bound for generated long integer
Returns:
a random long integer greater than or equal to lower and less than or equal to upper
Throws:
NumberIsTooLargeException - if lower >= upper
• #### nextSecureHexString

String nextSecureHexString(int len)
throws NotStrictlyPositiveException
Deprecated.
Generates a random string of hex characters from a secure random sequence.

If cryptographic security is not required, use nextHexString(int).

Parameters:
len - the length of the string to be generated
Returns:
a random string of hex characters of length len
Throws:
NotStrictlyPositiveException - if len <= 0
• #### nextSecureInt

int nextSecureInt(int lower,
int upper)
throws NumberIsTooLargeException
Deprecated.
Generates a uniformly distributed random integer between lower and upper (endpoints included) from a secure random sequence.

Sequences of integers generated using this method will be cryptographically secure. If cryptographic security is not required, nextInt(int, int) should be used instead of this method.

Definition: Secure Random Sequence

Parameters:
lower - lower bound for generated integer
upper - upper bound for generated integer
Returns:
a random integer greater than or equal to lower and less than or equal to upper.
Throws:
NumberIsTooLargeException - if lower >= upper.
• #### nextSecureLong

long nextSecureLong(long lower,
long upper)
throws NumberIsTooLargeException
Deprecated.
Generates a uniformly distributed random long integer between lower and upper (endpoints included) from a secure random sequence.

Sequences of long values generated using this method will be cryptographically secure. If cryptographic security is not required, nextLong(long, long) should be used instead of this method.

Definition: Secure Random Sequence

Parameters:
lower - lower bound for generated integer
upper - upper bound for generated integer
Returns:
a random long integer greater than or equal to lower and less than or equal to upper.
Throws:
NumberIsTooLargeException - if lower >= upper.
• #### nextPoisson

long nextPoisson(double mean)
throws NotStrictlyPositiveException
Deprecated.
Generates a random value from the Poisson distribution with the given mean.

Definition: Poisson Distribution

Parameters:
mean - the mean of the Poisson distribution
Returns:
a random value following the specified Poisson distribution
Throws:
NotStrictlyPositiveException - if mean <= 0.
• #### nextGaussian

double nextGaussian(double mu,
double sigma)
throws NotStrictlyPositiveException
Deprecated.
Generates a random value from the Normal (or Gaussian) distribution with specified mean and standard deviation.

Definition: Normal Distribution

Parameters:
mu - the mean of the distribution
sigma - the standard deviation of the distribution
Returns:
a random value following the specified Gaussian distribution
Throws:
NotStrictlyPositiveException - if sigma <= 0.
• #### nextExponential

double nextExponential(double mean)
throws NotStrictlyPositiveException
Deprecated.
Generates a random value from the exponential distribution with specified mean.

Definition: Exponential Distribution

Parameters:
mean - the mean of the distribution
Returns:
a random value following the specified exponential distribution
Throws:
NotStrictlyPositiveException - if mean <= 0.
• #### nextUniform

double nextUniform(double lower,
double upper)
throws NumberIsTooLargeException,
NotFiniteNumberException,
NotANumberException
Deprecated.
Generates a uniformly distributed random value from the open interval (lower, upper) (i.e., endpoints excluded).

Definition: Uniform Distribution lower and upper - lower are the location and scale parameters, respectively.

Parameters:
lower - the exclusive lower bound of the support
upper - the exclusive upper bound of the support
Returns:
a uniformly distributed random value between lower and upper (exclusive)
Throws:
NumberIsTooLargeException - if lower >= upper
NotFiniteNumberException - if one of the bounds is infinite
NotANumberException - if one of the bounds is NaN
• #### nextUniform

double nextUniform(double lower,
double upper,
boolean lowerInclusive)
throws NumberIsTooLargeException,
NotFiniteNumberException,
NotANumberException
Deprecated.
Generates a uniformly distributed random value from the interval (lower, upper) or the interval [lower, upper). The lower bound is thus optionally included, while the upper bound is always excluded.

Definition: Uniform Distribution lower and upper - lower are the location and scale parameters, respectively.

Parameters:
lower - the lower bound of the support
upper - the exclusive upper bound of the support
lowerInclusive - true if the lower bound is inclusive
Returns:
uniformly distributed random value in the (lower, upper) interval, if lowerInclusive is false, or in the [lower, upper) interval, if lowerInclusive is true
Throws:
NumberIsTooLargeException - if lower >= upper
NotFiniteNumberException - if one of the bounds is infinite
NotANumberException - if one of the bounds is NaN
• #### nextPermutation

int[] nextPermutation(int n,
int k)
throws NumberIsTooLargeException,
NotStrictlyPositiveException
Deprecated.
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.

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:
NumberIsTooLargeException - if k > n.
NotStrictlyPositiveException - if k <= 0.
• #### nextSample

Object[] nextSample(Collection<?> c,
int k)
throws NumberIsTooLargeException,
NotStrictlyPositiveException
Deprecated.
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.

Parameters:
c - the collection to be sampled
k - the size of the sample
Returns:
a random sample of k elements from c
Throws:
NumberIsTooLargeException - if k > c.size().
NotStrictlyPositiveException - if k <= 0.

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