Other S Functions

A variety of functions for correspondence analysis are available from Bernard Perbal of the Centre de Recherche Public - Centre Universitaire, Luxenbourg (perbal@crpcu.lu) and from Susan Holmes of INRA, Paris (susan@helios.montpellier.inra.fr). Holmes also has a very general PC analysis function.

See the Venables and Ripley MASS library for the latest functions for multidimensional scaling, clustering, correspondence analysis, and other multivariate techniques (http://www.stats.ox.ac.uk/pub/MASS2/sites.html).

Joseph Schafer has several S-PlUS functions for multiple imputation. See http://www.stat.psu.edu/~jls/.

Elizabeth Atkinson and Terry Therneau have written a very comprehensive recursive partitioning function, rpart, that is available on statlib. For now the Windows version may be obtained from http://www.stats.ox.ac.uk/pub/SWin/RPart.zip.

Segal and Wagner have written a program called TSSA (Tree Structured Survival Analysis) which runs on S-plus 3.1, 3.2, 3.3 and 4. I have run the program successfully on version 4 but have not been able to get the many of the "point and click" graphics options to work. I suspect this is a problem with my system configuration and not the program itself.

You can grab the source code from:

http://lib.stat.cmu.edu/S/tssa (Splus for Unix + standalone C)
http://www.stats.ox.ac.uk/pub/SWin/tssa.zip (Splus for Windows)

references are:

Segal (1988) Biometrics, 44:35-47
Segal and Bloch (1989) Statistics in Medicine, 8:539-550
Bacchetti and Segal (1995) Lifetime Data Analysis, 1,:35-47

Wim Penninx of the Delft University of Technology, The Netherlands (W.H.Penninx@TWI.TUDelft.nl) and Robert Gentleman of the University of Auckland, New Zealand (rgentle@mat.aukuni.ac.nz) have written S-PLUS functions for nonparametric estimation of S(t) with left, right, and interval-censored data (Penninx's functions allow multiple intervals per subject).

Newer functions for general censored data by Michael Fay faym@exchange.nih.gov are described below:

Motivated by previous postings to S-news (see Mark Stevenson's entries 5 Mar 1999, 10 Mar 1999), I have submitted 3 functions to statlib under the heading interval.tar.gz (or a zip version for windows) for handling interval censoring in survival -type data (i.e., if X is failure time, we ony observe L and R, where L < X <=R).

The functions are:

icfit - does nonparametric survival estimates using the self-consistent algorithm with some modifications suggested by Aragon and Eberly (1992) and Gentleman and Geyer (1994).
icplot - plots those estimates
ictest - does logrank or Wilcoxon type tests (see Finkelstein, 1986, Fay, 1996, Sun, 1996, Fay, 1999).
See the help files of the functions for the exact references.

See Lindsey and Ryan (Stat in Med 17:219-238; 1998) for a nice tutorial on interval censoring.

-- FrankHarrell - 15 Feb 2004