| cluster {survival} | R Documentation |
This is a special function used in the context of the Cox model. It identifies correlated groups of observations, and is used on the right hand side of a formula.
cluster(x)
x |
A character, factor, or numeric variable. |
The function's only action is semantic, to mark a variable as the cluster indicator.
x
## Not run: coxph(Surv(futime, fustat) ~ age + cluster(group), data = ovarian) ## End(Not run)