[R] using bootstrap for tree selection step in rpart

[Fiona Callaghan]

Hi Chris.  Thanks for replying.  I want to take the pruned list of
subtrees, and select the final tree from this list using a bootstrap
technique (rather than cross validation).   I think, and I could be wrong,
that bagging takes a bunch of bootstrap samples, grows one tree per
boostrap sample and then combines the estimates, but this is not want I
want to do.   I hope this is clearer.  It is difficult to describe these
things with eamil.
Cheers
Fiona
> Fiona Callaghan wrote:
>> I was wondering if someone could help me with an rpart problem.  I can
>> see
>> that cross-validation is the default for tree selection in rpart -- has
>> a
>> bootstrap method been implemented anywhere?  I think this is a different
>> thing to 'bagging' or 'boosting' -- I still want 'one' tree at the end,
>> I
>> just would like it chosen using a bootstrap method.  Any ideas???
>
> Hi Fiona,
>
> I'm not sure if I understand you correctly.
> To get one single rpart tree trained on one bootstrap sample, try
> bagging() from the 'ipred' package and set nbagg=1.
>
> Bye,
> Chris
>
>


-- 
Fiona Callaghan, MA MS
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Department of Biostatistics
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