sorry about the typo - it's 80 not 800.
"A J-sparse array implementation would have 10 sparse axis. This means that for every observation there would 10 extra numbers (i.e. integers). i.e. for each 8 bytes of useful data there needs to be 80 bytes of support (J64)." ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
