J has no explicit NA value. It is not simple to produce results like you want because even with all numeric data that include missing values, the missing values of "NA" are not numeric and complicate the production of results. Numeric NA values can be represented with J _. but this is very tricky and has been frowned upon whenever it is mentioned by the developer of J.
Wait for more responses from others who have used R. Maybe they have developed workarounds. -- (B=) <-----my sig Brian Schott ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
