| baseCH {extrafrail} | R Documentation |
Computes the baseline cumulative hazard function.
Description
Provides the baseline cumulative hazard function (\Lambda_0) for an object with extrafrail class.
Usage
baseCH(t, fit)
Arguments
t |
the vector of times for which the baseline cumulative hazard function should be computed. |
fit |
an object with extrafrail class. |
Details
Provides the baseline cumulative hazard function. When the baseline distribution is assumed as
the Weibull model, this function is \Lambda_0(t)=\lambda t^{\rho}. For the piecewise
exponential model, this function is \Lambda_0(t)=\sum_{j=1}^L \lambda_j \nabla_j(t),
where \nabla_j(t)=0, if t<a_{j-1}, \nabla_j(t)=t-a_{j-1}, if a_{j-1}\leq t < a_{j}
and \nabla_j(t)=a_j-a_{j-1}, if t\geq a_{j}, with a=(a_0=0, a_1, \ldots, a_{j-1}), the
corresponding partition time.
Value
a vector with the same length that t, including the baseline cumulative hazard function related to t.
Author(s)
Diego Gallardo and Marcelo Bourguignon.
References
Gallardo, D.I., Bourguignon, M. (2022) The multivariate weighted Lindley frailty model for cluster failure time data. Submitted.
Examples
#require(frailtypack)
require(survival)
data(rats, package="frailtyHL")
#Example for WL frailty model
fit.WL <- frailty.fit(survival::Surv(time, status) ~ rx + survival::cluster(litter),
dist.frail="WL", data = rats)
baseCH(c(80,90,100),fit.WL)