-----Original Message-----
From: NICOLAS DEIG
hello,
i am encoutering problems with a function of R concerning the
classification trees.
In the library {tree}, when I use the function "tree" to grow a
^^^^^^^ That should be "package"...
classification tree it should give me an object of class "tree". Then I should be allowed to use this "tree" object in the function "cv.tree" that requires an object of class "tree" in order to run a cross-validation experiment. There is the problem, when I do this the following message appears: "Error in as.data.frame.default(data) : can't coerce function into a data.frame". So instead of considering the object as an object of class tree the function "cv.tree" handles it like a data.frame. Does anyone knows why or how to work on a class "tree" object so that "cv.tree" can handle it?
Please show how you did it the the error you got. I can't reproduce the problem you described:
library(tree) iris.tree <- tree(Species ~ ., iris) iris.cvtree <- cv.tree(iris.tree) iris.cvtree
$size [1] 6 5 4 3 2 1 $dev [1] 52.33779 45.94317 46.28027 63.43450 151.84608 335.57375 $k [1] -Inf 4.228650 4.717398 15.957916 95.676543 190.954250 $method [1] "deviance" attr(,"class") [1] "prune" "tree.sequence" Andy
Thanks in advance... Nicolas Deig
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