Error in ConfusionMatrix the data and reference factors must have the same number of levels

Question

I\'ve trained a tree model with R caret. I\'m now trying to generate a confusion matrix and keep getting the following error:

Error in confusionMatrix

Answer 1

Might be there are missing values in the testdata, Add the following line before "predictionsTree <- predict(treeFit, testdata)" to remove NAs. I had the same error and now it works for me.

testdata <- testdata[complete.cases(testdata),]