Extract the name of the distribution family

Some distributions (such as dist_mixture(), dist_convolved(), dist_inflated() and dist_transformed()) are defined in terms of one or more other distributions. By default, family() only identifies the outermost distribution. Setting recursive = TRUE will also identify the families of these embedded distributions, returning a nested list describing the full family tree of each distribution.

# S3 method for class 'distribution'
family(object, recursive = FALSE, ...)

Arguments

object

The distribution(s).

recursive

If TRUE, the families of any distributions embedded within object (such as the components of a dist_mixture(), or the base distribution of a dist_inflated() or dist_transformed()) are also identified, and returned as a nested list instead of a flat character vector.

...

Additional arguments used by methods.

Value

If recursive = FALSE (the default), a character vector giving the family name of each distribution. If recursive = TRUE, a list with one element per distribution: a distribution with no embedded distributions is represented by a character scalar (as before), while a distribution built from others is represented by a named list with a family element and one element per embedded distribution (containing its recursive family() result, or a list of such results if that element holds more than one embedded distribution).

Examples

dist <- c(
  dist_normal(1:2),
  dist_poisson(3),
  dist_multinomial(size = c(4, 3),
  prob = list(c(0.3, 0.5, 0.2), c(0.1, 0.5, 0.4)))
  )
family(dist)
#> [1] "normal"      "normal"      "poisson"     "multinomial" "multinomial"

# Distributions composed of other distributions (such as the mixture
# below) only identify the outer family by default.
mix_dist <- dist_mixture(dist_normal(0, 1), dist_normal(5, 2),
  weights = c(0.3, 0.7))
family(mix_dist)
#> [1] "mixture"

# With recursive = TRUE, the families of the mixture's components are
# also identified.
family(mix_dist, recursive = TRUE)
#> [[1]]
#> [[1]]$family
#> [1] "mixture"
#> 
#> [[1]]$dist
#> [[1]]$dist[[1]]
#> [1] "normal"
#> 
#> [[1]]$dist[[2]]
#> [1] "normal"
#> 
#> 
#>