Hi Linda, I think the explanation is in the fact that:
(,1)#"1 '' |length error But 1#"1 '' works OK. i suspect empty is not an appropriate right arg for the verb, but if you insist, then perhaps you may need to special case it. enjoy ken -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Linda Alvord Sent: 04 October 2012 06:41 To: [email protected] Subject: [Jprogramming] Why the length error? rad=: 13 :'(A=:1,-. 2-:/\|:y)#"1 y' NB. Remove adjacent duplicates ]B=:2 4 $3 5 5 4 2 1 1 6 3 5 5 4 2 1 1 6 rad B 3 5 4 2 1 6 The verb rad works as expected, but suppose in an earlier step B has become empty, I get a length error. Why does this happen? C=:'' rad C |length error: rad | (A=:1,-.2-:/\|:y) #"1 y A 1 1#"1 C What can I do to get an empty result? Linda ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
