Dirichlet distribution

E466249

The Dirichlet distribution is a family of continuous multivariate probability distributions commonly used as a prior over categorical or multinomial parameters in Bayesian statistics.

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Observed surface forms (1)

Surface form Occurrences
Dirichlet distribution density 1

Statements (49)

Predicate Object
instanceOf conjugate prior
continuous distribution
exponential family distribution
multivariate distribution
probability distribution
appearsIn Bayesian text modeling NERFINISHED
document clustering
ecology
genetics
belongsTo multivariate continuous distributions
belongsToFamily Dirichlet family NERFINISHED
conjugateTo categorical distribution
multinomial distribution NERFINISHED
definedOn probability simplex
field machine learning
probability theory
statistics
generalizes beta distribution
hasDensityFunction proportional to product of powers of components
hasLimitingCase degenerate distribution on simplex as concentration goes to infinity
distribution concentrated on vertices of simplex as concentration goes to zero
hasProperty components are nonnegative
components sum to 1
exchangeable when parameters equal
mean equals normalized alpha parameters
variance decreases as concentration increases
hasSpecialCase beta distribution
namedAfter Peter Gustav Lejeune Dirichlet NERFINISHED
normalizingConstant multivariate beta function
parameterizedBy alpha vector
concentration parameters
parameterSpace positive real numbers
relatedTo Dirichlet process NERFINISHED
Dirichlet-multinomial distribution NERFINISHED
samplingMethod normalized gamma variables
support k-dimensional probability simplex
usedAs prior for categorical distribution
prior for multinomial distribution
usedFor Bayesian inference for multinomial parameters
modeling uncertainty over discrete probability vectors
prior over mixture weights
prior over topic proportions
smoothing categorical frequency estimates
usedIn Bayesian machine learning NERFINISHED
Bayesian mixture models NERFINISHED
Bayesian nonparametrics NERFINISHED
Bayesian statistics NERFINISHED
Latent Dirichlet Allocation NERFINISHED
topic modeling

Referenced by (2)

Full triples — surface form annotated when it differs from this entity's canonical label.

Gamma function normalizationConstantFor Dirichlet distribution
this entity surface form: Dirichlet distribution density
Peter Gustav Lejeune Dirichlet notableWork Dirichlet distribution