[R] How to prune using a validation set

[Therneau, Terry M., Ph.D.]

You will need to give more detail of exactly what you mean by "prune using a validation 
set".  THe prune.rpart function will prune at any value you want, what I suspect you are 
looking for is to compute the error of each possible tree, using a validation data set, 
then find the best one, and then prune there.

How do you define "best"?

Terry Therneau


On 02/26/2017 05:00 AM, r-help-request at r-project.org wrote:
> I'd like to use a different data ( validation) set for pruning my
> classification tree. Unfortunately there aren't arguments to get this in
> prune.rpart().
>
> Any suggestions?
>
> Thanks!
>
> Alfredo
>