Crate rand_distr

Generating random samples from probability distributions.

Re-exports

This crate is a super-set of the rand::distributions module. See the rand::distributions module documentation for an overview of the core Distribution trait and implementations.

The following are re-exported:

• The Distribution trait and DistIter helper type
• The Standard, Alphanumeric, Uniform, OpenClosed01, Open01 and Bernoulli distributions
• The weighted sub-module

Distributions

This crate provides the following probability distributions:

• Related to real-valued quantities that grow linearly (e.g. errors, offsets):
  • Normal distribution, and StandardNormal as a primitive
  • Cauchy distribution
• Related to Bernoulli trials (yes/no events, with a given probability):
  • Binomial distribution
• Related to positive real-valued quantities that grow exponentially (e.g. prices, incomes, populations):
  • LogNormal distribution
• Related to the occurrence of independent events at a given rate:
  • Pareto distribution
  • Poisson distribution
  • Exponential distribution, and Exp1 as a primitive
  • Weibull distribution
• Gamma and derived distributions:
  • Gamma distribution
  • ChiSquared distribution
  • StudentT distribution
  • FisherF distribution
• Triangular distribution:
  • Beta distribution
  • Triangular distribution
• Multivariate probability distributions
  • Dirichlet distribution
  • UnitSphere distribution
  • UnitBall distribution
  • UnitCircle distribution
  • UnitDisc distribution

Modules

uniform	A distribution uniformly sampling numbers within a given range.
weighted	Weighted index sampling

Structs

Alphanumeric	Sample a char, uniformly distributed over ASCII letters and numbers: a-z, A-Z and 0-9.
Bernoulli	The Bernoulli distribution.
Beta	The Beta distribution with shape parameters alpha and beta.
Binomial	The binomial distribution Binomial(n, p).
Cauchy	The Cauchy distribution Cauchy(median, scale).
ChiSquared	The chi-squared distribution χ²(k), where k is the degrees of freedom.
Dirichlet	The dirichelet distribution Dirichlet(alpha).
DistIter	An iterator that generates random values of T with distribution D, using R as the source of randomness.
Exp	The exponential distribution Exp(lambda).
Exp1	Samples floating-point numbers according to the exponential distribution, with rate parameter λ = 1. This is equivalent to Exp::new(1.0) or sampling with -rng.gen::<f64>().ln(), but faster.
FisherF	The Fisher F distribution F(m, n).
Gamma	The Gamma distribution Gamma(shape, scale) distribution.
LogNormal	The log-normal distribution ln N(mean, std_dev**2).
Normal	The normal distribution N(mean, std_dev**2).
Open01	A distribution to sample floating point numbers uniformly in the open interval (0, 1), i.e. not including either endpoint.
OpenClosed01	A distribution to sample floating point numbers uniformly in the half-open interval (0, 1], i.e. including 1 but not 0.
Pareto	Samples floating-point numbers according to the Pareto distribution
Pert	The PERT distribution.
Poisson	The Poisson distribution Poisson(lambda).
Standard	A generic random value distribution, implemented for many primitive types. Usually generates values with a numerically uniform distribution, and with a range appropriate to the type.
StandardNormal	Samples floating-point numbers according to the normal distribution N(0, 1) (a.k.a. a standard normal, or Gaussian). This is equivalent to Normal::new(0.0, 1.0) but faster.
StudentT	The Student t distribution, t(nu), where nu is the degrees of freedom.
Triangular	The triangular distribution.
Uniform	Sample values uniformly between two bounds.
UnitBall	Samples uniformly from the unit ball (surface and interior) in three dimensions.
UnitCircle	Samples uniformly from the edge of the unit circle in two dimensions.
UnitDisc	Samples uniformly from the unit disc in two dimensions.
UnitSphere	Samples uniformly from the surface of the unit sphere in three dimensions.
Weibull	Samples floating-point numbers according to the Weibull distribution

Enums

BetaError	Error type returned from Beta::new.
BinomialError	Error type returned from Binomial::new.
CauchyError	Error type returned from Cauchy::new.
ChiSquaredError	Error type returned from ChiSquared::new and StudentT::new.
DirichletError	Error type returned from Dirchlet::new.
ExpError	Error type returned from Exp::new.
FisherFError	Error type returned from FisherF::new.
GammaError	Error type returned from Gamma::new.
NormalError	Error type returned from Normal::new and LogNormal::new.
ParetoError	Error type returned from Pareto::new.
PertError	Error type returned from Pert constructors.
PoissonError	Error type returned from Poisson::new.
TriangularError	Error type returned from Triangular::new.
WeibullError	Error type returned from Weibull::new.

Traits

Distribution	Types (distributions) that can be used to create a random instance of T.
Float	Trait for floating-point scalar types