Error while calculating metrics like AUC, ACC in R

Question

I am trying to make predictions on my validation data using a decision tree model created with training data set. I am able to do that with success but, I am not able to calculate various metrics like Area under curve (AUC), and overall classification rate (ACC) using mmetric() command in R. Here is the screen shot with errors and commands that I used. Note: Right click the image and select view image to see it clearly. "t" is my training data set and "v" is validation data set.

Note: You can download my training data set "t" and validation data set "v" as a .csv files from here: Click here I used the same commands for a different data set and it worked perfectly, so could be this due to some problem with my data set.

Thanks,

P

Answer 1

You need to tell predict() to return classes and not probabilities:

vpredict=predict(tree,t,type="class")

The default for classification with predict.rpart() is to return a matrix with probabilities of each class. However, mmetric wants the classes.

(I also think people are having / have had difficulty helping because you did not include your data or information on the libraries your commands came from and you used a screenshot rather than text that people could copy and paste. Help us to help you! :-) )