Lexis function not found in R - r

Question

I am using this code from the R help guide in the Epi
package:
# A small bogus cohort
xcoh <- structure( list( id = c("A", "B", "C"),
birth = c("14/07/1952", "01/04/1954",
"10/06/1987"),
entry = c("04/08/1965", "08/09/1972",
"23/12/1991"),
exit = c("27/06/1997", "23/05/1995",
"24/07/1998"),
fail = c(1, 0, 1) ),
.Names = c("id", "birth", "entry", "exit",
"fail"),
row.names = c("1", "2", "3"),
class = "data.frame" )
# Define a Lexis object with timescales calendar time and
age
Lcoh <- Lexis( entry = list( per=entry ),
exit = list( per=exit,
age=exit-birth ),
exit.status = fail,
data = xcoh )
But I get this error:
Error in Lexis(entry = list(per = entry), exit = list(per = exit, age = exit - :
could not find function "Lexis"
Any thoughts?

Answer 1

Epi package first needs to be installed in the environment using:
install.packages("Epi")
And then the library for Epi needs to be loaded.
library(Epi)
Hence your code being modified as follows:
install.packages("Epi")
library(Epi)
xcoh <- structure( list( id = c("A", "B", "C"),
birth = c("14/07/1952", "01/04/1954",
"10/06/1987"),
entry = c("04/08/1965", "08/09/1972",
"23/12/1991"),
exit = c("27/06/1997", "23/05/1995",
"24/07/1998"),
fail = c(1, 0, 1) ),
.Names = c("id", "birth", "entry", "exit",
"fail"),
row.names = c("1", "2", "3"),
class = "data.frame" )
# Define a Lexis object with timescales calendar time and
Lcoh <- Lexis( entry = list( per=entry ),
exit = list( per=exit,
age=exit-birth ),
exit.status = fail,
data = xcoh )
Note: I have removed the line that says age. Assuming it is not relevant to the question posted here.