Dear all,

I have been doing some frailty calculations and been facing some
difficulties.
I can extract coefficients, value of theta and the following things

library(survival)
fit<-coxph(Surv(time,status)~covariate+frailty(group), data=simulated.data)
fit$coef
fit$history[[1]]$theta
fit$history[[1]]$c.loglik
fit$var
fit$var2

from a frailty included coxph object:
but how can i know what other possible things that i can extract from the
same object "fit"?

Also, i cannot use var2 (defined on page 122) as a function as Therneau,
Grembsch (2000) page 249 implemented in apply(), unlike var: why is that? Do
i need to define it first, or, the function is not for R?

Again, is there any already written complete program in R for estimating
frailty models with nested effects (at leat 2 stage)?

Thanks for you time: Thanks in advance: hope some one may help me with the
above quaries.


Mohammad Ehsanul Karim
Institute of Statistical Research and Training
University of Dhaka

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