Anssi Seppälä: > (+/ % #) 0$0 NB. mean of empty sample is also zero ! > 0 > > I wonder why (+/0$0) could not be 0$0 instead of 0 ? Because it must be scalar and there is no such thing as empty scalar.
You can use (+/ % $) 0$0 In this case result will be 1-element vector in case of non-empty list argument and empty vector in case of empty list argument. nsg ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
