Programs related to splitting of time as for example follow-up
through a Lexis diagram. The functionality in the stata-function
stsplit is implemented in R in the function splitLexis (in the 
R-package Epi) and for SAS in the macro %Lexis in the file Lexis.sas.

xLexis.R     - Example of running time-splitting in R
Lexis.sas    - SAS-macro for time splitting
xLexis.sas   - Example of running time-splitting in SAS using the Lexis macro.
xLexis.do    - Example of running time-splitting in Stata
Pois-ex.sas  - Example program showing how to use logistic regression to mimick
               Poisson regression with any desired accuracy.
PYtab.sas    - SAS-macro for person-years tabulation, to be used on output from
               the Lexis macro.