Get link-function from model object

Returns the link-function from a model object.

Usage

link_function(x, ...)

# S3 method for betamfx
link_function(x, what = c("mean", "precision"), ...)

# S3 method for gamlss
link_function(x, what = c("mu", "sigma", "nu", "tau"), ...)

# S3 method for betareg
link_function(x, what = c("mean", "precision"), ...)

# S3 method for DirichletRegModel
link_function(x, what = c("mean", "precision"), ...)

Arguments

x

A fitted model.

...

Currently not used.

what

For gamlss models, indicates for which distribution parameter the link (inverse) function should be returned; for betareg or DirichletRegModel, can be "mean" or "precision".

Value

A function, describing the link-function from a model-object. For multivariate-response models, a list of functions is returned.

Examples

# example from ?stats::glm
counts <- c(18, 17, 15, 20, 10, 20, 25, 13, 12)
outcome <- gl(3, 1, 9)
treatment <- gl(3, 3)
m <- glm(counts ~ outcome + treatment, family = poisson())

link_function(m)(0.3)
#> [1] -1.203973
# same as
log(0.3)
#> [1] -1.203973