[R] contingency table

[Prof Brian Ripley]

Try looking at 'prev' (it is a matrix) and then reading ?predict.rpart to 
see why.  My guess is that you intended type="class".

On Thu, 14 Feb 2008, Carla Rebelo wrote:

> Hello!
>
> May you help me? I'm trying to do a contingency table using this
>
> > data(iris)
> > library(rpart)
> > modelo <- rpart(Species ~., iris)
> > prev <- predict(modelo, iris)
>
> Finally the contingency table
> > table(iris$Species, prev)
> But an error occurs:
> Error in table(iris$Species, prev) :
>  all arguments must have the same length
>
> And I do not understand why, may you help me?
>
> Thank You!
>
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-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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