R help - Feb 2015 - xerror and xstd are missing from cptable of the Rpart package

Hello all, 
I'm making a decision tree with the rpart package. I want to prune the tree
and in many tutorials it says to use cptable. Like so: opt <-
which.min(model_rpart$cptable[, "xerror"])
The problem is that when I look up model_rpart$cptable it only show the columns
CP, nsplit, rel error. So xerror and xstd are missing. How can this be?
Model looks like this: model <- rpart(Product~. , data=trainData,
control=rpart.control(minsplit=50, cp=0.002, xval=0))

Thank you. 
Kim  		 	   		  
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Kim,

The "x" in "xerror" and "xstd" stands for cross
validation.  But you have
specified no cross validations, xval=0.

Try:

model <- rpart(Product ~ ., data=trainData,
control=rpart.control(minsplit=50,
cp=0.002))
model$cptable

Jean


On Tue, Feb 3, 2015 at 7:09 AM, Kim C. <minorthreatx at hotmail.com>
wrote:
> Hello all,
> I'm making a decision tree with the rpart package. I want to prune the
> tree and in many tutorials it says to use cptable. Like so: opt <-
> which.min(model_rpart$cptable[, "xerror"])
> The problem is that when I look up model_rpart$cptable it only show the
> columns CP, nsplit, rel error. So xerror and xstd are missing. How can this
> be?
> Model looks like this: model <- rpart(Product~. , data=trainData,
> control=rpart.control(minsplit=50, cp=0.002, xval=0))
>
> Thank you.
> Kim
>         [[alternative HTML version deleted]]
>
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