[R] rpart unbalanced data

[Gabor Grothendieck]

Check this thread:

http://finzi.psych.upenn.edu/R/Rhelp02a/archive/40898.html

On 7/21/06, helen.mills at yale.edu <helen.mills at yale.edu> wrote:
> Hello all,
> I am currently working with rpart to classify vegetation types by spectral
> characteristics, and am comming up with poor classifications based on the fact
> that I have some vegetation types that have only 15 observations, while others
> have over 100. I have attempted to supply prior weights to the dataset, though
> this does not improve the classification greatly. Could anyone supply some
> hints about how to improve a classification for a badly unbalanced datase?
>
> Thank you,
> Helen Mills Poulos
>
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