Easy way of counting precision, recall and F1-score in R

Question

I am using an rpart classifier in R. The question is - I would want to test the trained classifier on a test data. This is fine - I can use the predict.rpart<

Answer 1

The ROCR library calculates all these and more (see also http://rocr.bioinf.mpi-sb.mpg.de):

library (ROCR);
...

y <- ... # logical array of positive / negative cases
predictions <- ... # array of predictions

pred <- prediction(predictions, y);

# Recall-Precision curve             
RP.perf <- performance(pred, "prec", "rec");

plot (RP.perf);

# ROC curve
ROC.perf <- performance(pred, "tpr", "fpr");
plot (ROC.perf);

# ROC area under the curve
auc.tmp <- performance(pred,"auc");
auc <- as.numeric(auc.tmp@y.values)

...