The following could probably behave better: > test$TESTFAC <- NULL > test NULL data frame with 8 rows > summary(test) Error in z[[i]] : subscript out of bounds In addition: Warning message: no finite arguments to max; returning -Inf (rw2001 on win XP) Kjetil -- Kjetil Halvorsen. Peace is the most effective weapon of mass construction. -- Mahdi Elmandjra