This file contains programs written in SPlus and Fortran to implement the 
methods described in "Analysis of a Randomized Trial to Prevent Vertical 
Transmission of HIV-1" by J.P. Hughes and B.A. Richardson, JASA, Dec. 2000.

This software can be freely used and redistributed for non-commercial 
purposes only.

The following programs are included in this tarfile:

README - this file
combined.s - does nonparametric estimate of joint distribution of HIV
             infection time and death (see Hughes and Richardson, JASA,
             Dec. 2000 (tent.))
combined.f - associated fortran routines called by combined.s
weibspl.s - does semiparametric estimate of joint distribution of HIV
             infection time and death (see Hughes and Richardson, JASA,
             Dec. 2000 (tent.))
weibspl.f - associated fortran routines called by weibspl.s
example.s - example S session
example.sdata - S formatted data and result objects

Both programs (combined and weibspl) are documented in the respective
.s program file. To use either program you need to do the following
(% is the unix prompt and > is the Splus prompt).

% f77 -O -c combined.f
% f77 -O -c weibspl.f
% Splus
> source("combined.s")
> source("weibspl.s")

Expect some variation across systems - I did all this on a Decstation
running Ultrix with Splus version 3.1. In particular, note that
1) both combined.s and weibspl.s include dyn.load() functions to load the
   Fortran object files. You may have to change this for your system.
2) weibspl.s loads the Therneau survival package, which is standard on
   later versions of S. The function survfit() (and supporting routines)
   is used from this package.

Report problems/comments to Jim Hughes (hughes@biostat.washington.edu)
