rfrailty {rsurv}

Frailties random generation

Description

The frailty function for adding a simple random effects term to the linear predictor of a given survival regression model.

Usage

rfrailty(
  cluster,
  frailty = c("gamma", "gaussian", "ps"),
  sigma = 1,
  alpha = NULL,
  ...
)

Arguments

cluster

the variable to be entered as a random effect (always converted to a factor object internally).

frailty

the frailty distribution; current implementation includes the gamma (default), lognormal and positive stable (ps) distributions.

sigma

standard deviation assumed for the frailty distribution; sigma = 1 by default; this value is ignored for positive stable (ps) distribution.

alpha

stability parameter of the positive stable distribution; alpha must lie in (0,1) interval and an NA is return otherwise.

...

further arguments passed to other methods.

Value

a vector with the generated frailties.