Rafa OR Rafa OR - 11 months ago 55
R Question

Change default arguments of ROC computation (pROC) in the RFE process (caret) - R

I am computing a SVM-RFE model using

as the metric, with the
function (
package). To my knowledge, the
algorithm optimizes the AUC values using the
function of the
package, with its predefined arguments. However, I would like to set the
argument to
instead of
because in some cases the resulting average AUC is computed in reverse (my data is not very good...). This problem is explained in the answer here: Difference in average AUC computation using ROCR and pROC (R)

How could I change this default argument value of the
function in the

I have tried this simple option, but it does not work:

svmRFE_NG3 <- rfe(x = TAll[,2:50],
y = TAll[,1],
sizes = seq(1,42),
metric = "ROC",
levels = c("BREAST","LUNG"),
direction = "<",
rfeControl = FSctrl,
## Options to train()
method = "svmLinear",
tuneLength = 10,
preProc = c("center", "scale"),
## Inner resampling process
trControl = TRctrl)

Answer Source

I had a look at the source code of caret, and it doesn't seem to be readily possible at the moment. Arguments are not passed down to the call to the roc function.

I would suggest submitting a request for enhancement on the github repository of the package. Max Kuhn the maintainer is pretty responsive and you have a good chance to see this implemented in a future version.