[R] Finding indices of NA values in a data frame

[Ken Termiso]

Hi all,

I've got a data frame with NA values scattered throughout. I would like to 
find the rows which contain an NA. Trying to find the indices of the NAs 
with grep() doesn't work (apparently you can't convert NA to "NA" character 
value, even with as.character()) so I was hoping someone could tell me how 
to find rows which contain NA.

Thanks in advance,
-Ken