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I have a question about what is considered good style in R. I have a function which returns several arguments, say [x,y,z]=f(), where sometimes I only care about the first few (so in Matlab, I can write...

I would like to specify that certain columns in a data frame should be treated as ordered factors. I know what numbers these columns are, but not their names. How do I do this? For example, if I know columns...

I am having trouble installing the tree package on linux. I followed all the steps in section 5.2 of the FAQ http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html#How%20can%20add-on%20packages%20be%20installed...

The following code tr <- rpart(Y ~ ., dat, method="class") dev <- residuals(tr, "deviance") produces the following error Error in log(x) : Non-numeric argument to mathematical function > .Traceback [[1]] [1] "log(yhat)" # line 588 of rpart [[2]] [1] "switch(type...

Re: teaching computer science - I'm surprised nobody has recommended using the classic "Structure and Interpretation of Computer Programs", by Abelson, Sussman, and Sussman (1984/1996) (http://mitpress.mit.edu/sicp/sicp.html), especially since R is so closely modelled...

Has anyone implemented AIC for trees? I realise that the tree growing procedure does variable selection automatically - my goal is to learn belief net structure where the local conditional probability distributions (CPDs) are represented by trees (as in e.g...

I can build a tree at the command line using tr <- tree(V4 ~ ., dat) but I don't know how to build one inside a function - the following does not work foo <- function(dummy) { tr <- tree(V4 ~ ., dummy) } tr2 <- foo...

Hi, I have noticed that aperm is very slow, and I wondered if there was a way of speeding it up. Let me tell you a bit about the context of my problem, because perhaps I shouldn't be using...

I am new to R, and didn't know which list to send this to, since it is a bug report about a package, not about core R... I have created a regression tree using 4 predictors: 3 are unordered...