[R] To get more digits in precision of predict function of randomForests

[Nagu]

Thank you Uwe Ligges.

Yes. I had only 50 trees. I come across memory problems running for
big number of trees. Also, I am going to post my next question in a
separate thread, but, it does not harm me to ask here. How do I deal
with large datasets when using randomForests. I have approximately,
datasets of size 500000X650, and R just can't deal with it (pops up
memory allocation problems). Are there any better ways to deal with
large datasets in R, for example, Splus had something like bigData
library.

Thank you,
Nagu

On Mon, Feb 25, 2008 at 1:56 AM, Uwe Ligges
<ligges at statistik.tu-dortmund.de> wrote:
>
>
>
>  Nagu wrote:
>  > Hi,
>  >
>  > I am using randomForests for a classification problem. The predict
>  > function in the randomForest library, when asked to return the
>  > probabilities, has precision of two digits after the decimal. I need
>  > at least four digits of precision for the predicted probabilities. How
>  > do I achieve this?
>
>  For me it gives the desired precision, adapting the
>  ?predict.randomForest example:
>
>  data(iris)
>  set.seed(111)
>  ind <- sample(2, nrow(iris), replace = TRUE, prob=c(0.8, 0.2))
>  iris.rf <- randomForest(Species ~ ., data=iris[ind == 1,], ntree = 2000)
>  iris.pred <- predict(iris.rf, iris[ind == 2,], type = "prob")
>  iris.pred
>
>  Maybe you do not have much more than 1000 trees in your bag?
>
>  Uwe Ligges
>
>
>
>
>
>
>
>  >
>  > Thank you,
>  > Nagu
>  >
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