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

Life.lines {Epi} | R Documentation

## 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 ) )

[Package Epi version 2.37 Index]