R help - Jul 2012 - ROC curves with ROCR

Hi, 

I don't really understand how ROCR works.  Here's another example with a
randomforest model: I have the training dataset(bank_training) and testing
dataset(bank_testing) and I ran a randomForest as below:

    bankrf<-randomForest(y~., bank_training, mtry=4, ntree=2,  
    keep.forest=TRUE,importance=TRUE)         
    bankrf.pred<-predict(bankrf, bank_testing)
    library(ROCR)
    pred<-prediction(bankrf.pred$y, bank_testing$y)

Here I get the error that the prediction format is incorrect? Where is the
mistake?

Thanks in advance

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Wild guess :
You need to have some kind of score for ROC to work (so you can work with a
threshold), so a predict() that only returns classlabels probably won't
work.

On 13.07.2012, at 15:25, blerta wrote:
> Hi, 
> 
> I don't really understand how ROCR works.  Here's another example
with a
> randomforest model: I have the training dataset(bank_training) and testing
> dataset(bank_testing) and I ran a randomForest as below:
> 
>    bankrf<-randomForest(y~., bank_training, mtry=4, ntree=2,  
>    keep.forest=TRUE,importance=TRUE)         
>    bankrf.pred<-predict(bankrf, bank_testing)
>    library(ROCR)
>    pred<-prediction(bankrf.pred$y, bank_testing$y)
> 
> Here I get the error that the prediction format is incorrect? Where is the
> mistake?
> 
> Thanks in advance
> 
> --
> View this message in context:
http://r.789695.n4.nabble.com/ROC-curves-with-ROCR-tp4636435.html
> Sent from the R help mailing list archive at Nabble.com.
> 
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