[R] AFTREG with ID argument

[Philipp Rappold]

Dear all,

I have some trouble using the "id"-argument with aftreg (accelerated 
failure time regression analysis from the eha library).

As far as I understand it, the id argument is used to group 
individuals together if there are time-varying covariates and the 
data is arranged in counting process style.

Unfortunately, i cannot figure out how to use the "id"-argument. The 
most straight-forward way would be to simply state the grouping 
variable, but it throws an error. I've included an example below: 
the dataframe for regression is called "test", with the grouping 
variable "person".

 > test
   start end censor person var1
1     0   1      0      1  0.5
2     1   2      0      1  0.4
3     2   3      0      1  0.6
4     3   4      1      1 -0.3
5     0   1      0      2  0.6
6     1   2      0      2  0.7
7     2   3      0      2  0.6

 > fit <- aftreg(Surv(start, end, censor)~var1, data=test, id=person)
Error in order(id, Y[, 1]) : argument 1 is not a vector

 > fit <- aftreg(Surv(start, end, censor)~var1, data=test, 
id=test["person"])
Error in `[.data.frame`(id, ord) : undefined columns selected



What would be the correct way to fit this example model?

Thanks + all the best
Philipp