Life.lines: Compute dates/ages for life lines in a Lexis diagram

In Epi: Statistical Analysis in Epidemiology

Compute dates/ages for life lines in a Lexis diagram

Description

Fills out the missing information for follow up of persons in a Lexis diagram if sufficient information is given.

Usage

Life.lines( entry.date = NA,
             exit.date = NA,
            birth.date = NA,
             entry.age = NA,
              exit.age = NA,
             risk.time = NA )

Arguments

entry.date, exit.date, birth.date, entry.age, exit.age, risk.time

Vectors defining lifelines to be plotted in the diagram. At least three must be given to produce a result. Not all subsets of three will suffice, the given subset has to define life lines. If insufficient data is given, nothing is returned and a warning is given.

Value

Data frame with variables entry.date, entry.age, exit.date, exit.age, risk.time, birth.date, with all entries computed for each person. If any of entry.date, exit.date or birth.date are of class Date or if any of entry.age, exit.age or risk.time are of class difftime the date variables will be of class Date and the other three of class difftime.

See Also

Lexis.diagram, Lexis.lines

Examples

( Life.lines( entry.age = c(3,30,45),
              risk.time = c(25,5,14),
             birth.date = c(1970,1931,1925.7) ) )

# Draw a Lexis diagram
Lexis.diagram()

# Compute entry and exit age and date.
( LL <-  Life.lines( entry.age = c(3,30,45),
                     risk.time = c(25,5,14),
                    birth.date = c(1970,1931,1925.7) ) )
segments( LL[,1], LL[,2], LL[,3], LL[,4] ) # Plot the life lines.

# Compute entry and exit age and date, supplying a date variable
bd <- ( c(1970,1931,1925.7) - 1970 ) * 365.25
class( bd ) <- "Date"
( Life.lines( entry.age = c(3,30,45),
              risk.time = c(25,5,14),
             birth.date = bd ) )

Epi documentation built on Nov. 5, 2025, 7:37 p.m.