[R] Jackknife and rpart

chumpmonkey@hushmail.com chumpmonkey at hushmail.com
Wed Apr 16 19:28:08 CEST 2003


First, thanks to those who helped me see my gross misunderstanding of
randomForest. I worked through a baging tutorial and now understand the
"many tree" approach. However, it is not what I want to do! My bagged
errors are accpetable but I need to use the actual tree and need a single
tree application. 

I am using rpart for a classification tree but am interested in a more
unbaised estimator of error in my tree. I lack sufficent data to train
and test the tree and I'm hoping to bootstrap, or rather jacknife, an
error estimate.

I do not think the rpart.object can be applied to the jackknife function
in bootstrap but can I do something as simple as:

for(i in 1:number of samples){
  remove i from the data
  run the tree
  compare sample[i] to the tree using predict
  create an error matrix}

This would give me a confussion matrix of data not included in the tree's

Am I being obtuse again?

Thanks, CM

More information about the R-help mailing list