Learn R Programming
Epi (version 1.1.71)

start.Lexis: Time series methods for Lexis objects

Description

Extract the entry time, exit time, status or duration of follow-up from a Lexis object.

Usage

entry(x, time.scale = NULL, by.id=FALSE)
  exit(x, time.scale = NULL, by.id=FALSE)
status(x, at="exit"        , by.id=FALSE)
   dur(x,                    by.id=FALSE)

Arguments

x
an object of class Lexis.
time.scale
a string or integer indicating the time scale. If omitted, all times scales are used.
by.id
Logical, if TRUE, only one record per unique value of lex.id is returned; either the first, the last or for dur, the sum of lex.dur. If TRUE, the returned object have the lex.id<
at
string indicating the time point(s) at which status is to be measured.

Value

  • The entry and exit functions return a vector of entry times and exit times, respectively, on the requested time scale. If multiple time scales are requested, then a matrix is returned.

    The status function returns a vector giving the status at entry or exit and dur returns a vector with the lengths of the follow-up intervals.

See Also

Lexis