Hi!
>How to compute probabilities of survival from rpart object? Consider the
>following example:
>
>library(rpart)
>survtree <- rpart(Surv(time,status)~., data=aml)
>
>This code will produce the following survival tree:
>
> 1. root 23 26.44184 1.0000000
> 2. x=Maintained 11 12.61182 0.6848303 *
> 3. x=Nonmaintained 12 10.81338 1.4426070 *
>
>If I am not wrong the rightmost numbers are relative risks compared to
>whole population (e.g. root >node). How to get survival probability
>function S(t|x)?
After (almost) one year I am finally able to answer myself "from the
future"
:).
Create rpart tree and for every population from tree's leaf generate
Kaplan-Meier curve. For new sample use curve which corresponds to
combination of example's attributes.
For details refer to:
M. Radespiel-Troeger et al. (2003), Comparison of tree-based methods for
prognostic stratication of survival data, Articial Intelligence in
Medicine 28 (3): 323--341.
Regards,
Ludvik