In
probability theory
Probability theory is the branch of mathematics concerned with probability. Although there are several different probability interpretations, probability theory treats the concept in a rigorous mathematical manner by expressing it through a set ...
, a hyper-Erlang distribution is a
continuous probability distribution
In probability theory and statistics, a probability distribution is the mathematical function that gives the probabilities of occurrence of different possible outcomes for an experiment. It is a mathematical description of a random phenomenon ...
which takes a particular
Erlang distribution
The Erlang distribution is a two-parameter family of continuous probability distributions with support x \in independent exponential distribution">exponential variables with mean 1/\lambda each. Equivalently, it is the distribution of the tim ...
E
''i'' with probability ''p''
''i''. A hyper-Erlang distributed random variable ''X'' has a
probability density function
In probability theory, a probability density function (PDF), or density of a continuous random variable, is a function whose value at any given sample (or point) in the sample space (the set of possible values taken by the random variable) ca ...
given by
:
where each ''p''
''i'' > 0 with the ''p''
''i'' summing to 1 and each of the E
''l''''i'' being an
Erlang distribution
The Erlang distribution is a two-parameter family of continuous probability distributions with support x \in independent exponential distribution">exponential variables with mean 1/\lambda each. Equivalently, it is the distribution of the tim ...
with ''l''
''i'' stages each of which has parameter ''λ''
''i''.
See also
*
Phase-type distribution
References
{{ProbDistributions, continuous-semi-infinite
Continuous distributions