R xgboost on caret attempts to perform classification instead of regression

Question

everyone.

first, data sample is here:

> str(train)
\'data.frame\':   30226 obs. of  71 variables:
 $ sal              : int  2732 2732 2732 2328 2560         


        

Answer 1

It's not strange that caret thinks you are asking for classification, because you are actually doing so in these 2 lines of your trainControl function:

classProbs = TRUE,     
summaryFunction = twoClassSummary

Remove both these lines (so as they take their default values - see the function documentation), and you should be fine.

Notice also that AUC is only applicable to classification problems.

UPDATE (after comments): Seems that the target variable being integer causes the problem; convert it to double before running the model with

train$sal <- as.double(train$sal)