I want an effecient method of finding nub and key of a inverted table (rank-1 box array with equal number of items in each cells). eg.
]i=. (,.0 2 1 0 2 1 1 1 2 1);10 2$'aaaabaaaabbabbbababb' +-+--+ |0|aa| |2|aa| |1|ba| |0|aa| |2|ab| |1|ba| |1|bb| |1|ba| |2|ba| |1|bb| +-+--+ NB. nub of i ifa ~. a=. afi i +-+--+ |0|aa| |2|aa| |1|ba| |2|ab| |1|bb| |2|ba| +-+--+ NB. key of i a i.~ ~.a 0 1 2 0 3 2 4 2 5 4 NB. definition of afi and ifa afi |:@:(<"_1@>) ifa <@(>"1)@|: Although nub and key can be found using afi/ifa, it involves a lot of box, I worry the time and space efficency when the table is large. Can anyone suggest other ways to do it. -- regards, ==================================================== GPG key 1024D/4434BAB3 2008-08-24 gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3 gpg --keyserver subkeys.pgp.net --armor --export 4434BAB3 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
