Readme

This is my survival tree program (STREE).  It is free to use and
distribute provided that (a) I bear no responsibility as the
consequence of using this program although I welcome collaborations of
using my program for data analysis; (b) the users must acknowledge the
use of this STREE program; and (c) the users are recommended to cite
my book:

H.P. Zhang and B. Singer. (1999) Recursive Partitioning in the
Health Sciences, Springer, New York.


Thanks.

Heping Zhang (December 7, 2000)

sample.dat: This is a sample data file. The first row indicates the 
         type of covariates. "d" implies deleting that covariate from the
         analysis; "o" implies a continuous or an ordinal covariate; "n" 
         implies a nominal covariate; "r" implies the survival time; and
         "c" is for censoring indicator (1=death, 0=alive).

sample.inf:   The output file. The file can be read as follows:
         Column 1: node number. Node 1 is the root node.
         Column 2: number of subjects in the node, e.g., 2418 subjects
                   in node 2.
         Column 3: left daughter node, e.g. node 2 is the left daughter
                   node of node 1.
         Column 4: right daughter node, e.g. node 3 is the right daughter
                   node of node 1.
         Column 5: The splitting variables. For example, variable 1 splits
                   node 1.
         Column 6: The splitting value corresponds to the splitting 
                   variable.

sample.ps:  A postscript file for the final tree that can be viewed or
         printed. For each node on a tree, median survival time and death
         rate are printed. You have to make your own survival curves within
         the terminal nodes.

Final notes: I won't be surprised that you might have questions when you
         try to use this program. I would appreciate your understanding
         for not asking me questions, because this is a freeware.