risksets: Finds the compositions and sizes of risk sets
Description
Focus is on the risk set composition just prior to a failure.
Usage
risksets(x, strata = NULL, max.survs = NULL, members = TRUE)
Arguments
x
A Surv object.
strata
Stratum indicator.
max.survs
Maximum number of survivors in each risk set. If
smaller than the 'natural number', survivors are sampled from the
present ones. No sampling if missing.
members
If TRUE, all members of all risk sets are listed in the
resulting list, see below.
Value
A list with components
antrs
No. of risk sets in each stratum. The number of strata is
given by length(antrs).
risktimes
Ordered distinct failure time points.
eventset
If 'members' is TRUE, a vector of pointers to events
in each risk set, else NULL.
riskset
If 'members' is TRUE, a vector of pointers to
the members of the risk sets, in order. The 'n.events'
first are the events. If 'members' is FALSE, 'riskset' is NULL.
size
The sizes of the risk sets.
n.events
The number of events in each risk set.
sample_fraction
The sampling fraction of survivors in each risk
set.
Details
If the input argument max.survs is left alone, all survivors are
accounted for in all risk sets.