[R] ROCR crashes for simple recall plot

[Yang Zhang]

I'm trying to use ROCR to create a simple cutoff vs recall plot
(recall at p) on the example ROCR.simple dataset:

library(ROCR)
data(ROCR.simple)
pred <- prediction(ROCR.simple$predictions, ROCR.simple$labels)
perf <- performance(pred, "rec")
plot(perf)

But R crashes on me on the last line.

I'm using R 2.14.1, ROCR 1.0-4.  Any ideas?  Thanks in advance.

-- 
Yang Zhang
http://yz.mit.edu/