linkfun {VGAM}R Documentation

Link Functions for VGLMs

Description

Returns the link functions, and parameter names, for vector generalized linear models (VGLMs).

Usage

linkfun(object, ...)
linkfunvlm(object, earg = FALSE, ...)

Arguments

object

An object which has parameter link functions, e.g., has class "vglm".

earg

Logical. Return the extra arguments associated with each link function? If TRUE then a list is returned.

...

Arguments that might be used in the future.

Details

All fitted VGLMs have a link function applied to each parameter. This function returns these, and optionally, the extra arguments associated with them.

Value

Usually just a (named) character string, with the link functions in order. It is named with the parameter names. If earg = TRUE then a list with the following components.

link

The default output.

earg

The extra arguments, in order.

Note

Presently, the multinomial logit model has only one link function, multilogitlink, so a warning is not issued for that link. For other models, if the number of link functions does not equal M then a warning may be issued.

Author(s)

Thomas W. Yee

See Also

linkfun, multilogitlink, vglm.

Examples

pneumo <- transform(pneumo, let = log(exposure.time))
fit1 <- vglm(cbind(normal, mild, severe) ~ let, propodds, data = pneumo)
coef(fit1, matrix = TRUE)
linkfun(fit1)
linkfun(fit1, earg = TRUE)

fit2 <- vglm(cbind(normal, mild, severe) ~ let, multinomial, data = pneumo)
coef(fit2, matrix = TRUE)
linkfun(fit2)
linkfun(fit2, earg = TRUE)

[Package VGAM version 1.1-10 Index]