R help - Feb 2008 - To get more digits in precision of predict function of randomForests

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?

Thank you,
Nagu

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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