Variate Types¶
Variate¶
Variate
is an abstract type that serves as the basis for several concrete types in the Mamba package. Conceptually, it represents a data structure that stores numeric values sampled from a target distribution. As an abstract type, Variate
cannot be instantiated and cannot have fields. It can, however, have method functions, which descendant subtypes will inherit. Such inheritance allows one to endow a core set of functionality to all subtypes by simply defining the functionality once on the abstract type (see julia Types). Accordingly, a core set of functionality is defined for the Variate
type through the field and method functions summarized below. Although the (abstract) type does not have fields, its method functions assume that all subtypes will be declared with the value
field shown.
Declaration¶
abstract Variate{T<:Union(VariateType, Array{VariateType})}
Aliases¶
typealias VariateType Float64
typealias UniVariate Variate{VariateType}
typealias MultiVariate{N} Variate{Array{VariateType,N}}
typealias VectorVariate MultiVariate{1}
typealias MatrixVariate MultiVariate{2}
Field¶
value::T
: a scalar or array ofVariateType
values that represent samples from a target distribution.
Methods¶
Method functions supported on all Variate
types are summarized in the following sections; and, unless otherwise specified, are detailed in The Julia Standard Library documentation.
Array Functions¶
cummin cumsum maximum prod
cummax cumsum_kbn minimum sum
cumprod diff norm sum_kbn
Collections¶
endof size show
length getindex showcompact
ndims setindex!
Distributions¶
The univariate, multivariate, and matrix distributions described in the Distributions Section are supported.
Linear Algebra¶
dot
Mathematical Operators and Elementary Functions¶
The basic numerical Mathematical Operators and Elementary Functions of the julia language are supported, and the ones below added.
Function | Description |
---|---|
logit(x) |
log-odds |
invlogit(x) |
inverse log-odds |
Statistics¶
cor median var
cov std varm
mean stdm
Subtypes¶
Subtypes of Variate
include the Dependent, Logical, and Stochastic types, as well as the those defined for supplied Sampling Functions.