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!
I don't know if this you want but, you can try: table(data.frame(prev, iris$Species)) On 14/02/2008, Carla Rebelo <crebelo at liaad.up.pt> wrote:> Hello! > > May you help me? I'm trying to do a contingency table using this > > > data(iris) > > library(rpart) > > modelo <- rpart(Species ~., iris) > > prev <- predict(modelo, iris) > > Finally the contingency table > > table(iris$Species, prev) > But an error occurs: > Error in table(iris$Species, prev) : > all arguments must have the same length > > And I do not understand why, may you help me? > > Thank You! > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >-- Henrique Dallazuanna Curitiba-Paran?-Brasil 25? 25' 40" S 49? 16' 22" O
Try looking at 'prev' (it is a matrix) and then reading ?predict.rpart to see why. My guess is that you intended type="class". On Thu, 14 Feb 2008, Carla Rebelo wrote:> Hello! > > May you help me? I'm trying to do a contingency table using this > > > data(iris) > > library(rpart) > > modelo <- rpart(Species ~., iris) > > prev <- predict(modelo, iris) > > Finally the contingency table > > table(iris$Species, prev) > But an error occurs: > Error in table(iris$Species, prev) : > all arguments must have the same length > > And I do not understand why, may you help me? > > Thank You! > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >-- Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595
Have a look at length(iris$Species) length(prev) --- Carla Rebelo <crebelo at liaad.up.pt> 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! > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, > reproducible code. >