Re: [R] randomForest Error passing string argument

From: Uwe Ligges <ligges_at_statistik.uni-dortmund.de>
Date: Tue 16 Aug 2005 - 06:12:42 EST

mmv wrote:

> I'm attempting to pass a string argument into the function
> randomForest but I get an error:
>
> state <- paste(list("fruit ~", "apples+oranges+blueberries",
> "data=fruits.data, mtry=2, do.trace=100, na.action=na.omit,
> keep.forest=TRUE"), sep= " ", collapse="")

I really don't understand why you want it as a character. I think you probably want to generate arguments dynamically and specify them in form of a list, which leads to constructions using do.call() at the end.

Anyway, if you really want to call randomForest with the abouve text, I guess this is one of tzhe few circumstances where you can do eval(parse(.....)):

state <- paste("fruit ~", "apples+oranges+blueberries,",

   "data=fruits.data, mtry=2, do.trace=100, na.action=na.omit,     keep.forest=TRUE")
the_call <- paste("randomForest(", state, ")") eval(parse(text=the_call))

Uwe Ligges

> model.rf <- randomForest(state)
>
> Error in if (n==0) stop ("data(x) has 0 rows") argument is of length zero.
>
> -Thanks in advance,
>
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R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Tue Aug 16 06:12:40 2005

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