Explicit: I.x=y ; tacit: I.@:= , with the latter being supported by special code.
x=: 1e6 [EMAIL PROTECTED] 5e5 y=: ? 5e5 ts=: 6!:2 , 7!:[EMAIL PROTECTED] ts 'I. x=y' 0.00606027 1.04922e6 ts 'x I.@:= y' 0.0024654 524992 http://www.jsoftware.com/help/release/edot504.htm ----- Original Message ----- From: "metaperl.j" <[EMAIL PROTECTED]> Date: Tuesday, October 9, 2007 5:04 Subject: [Jgeneral] finding the index of an element in a list To: [email protected] > I would be interested in seeing an explicit solution to this... > implicitwould be interesting, but I mainly want to see the > explicit solution: > > NB. find the index of a value in a list > NB. list indexOf value > NB. 9 4 6 indexOf 4 would yield 1 > indexOf =: 4 : 0 > indices =: i. # x > tally_map =: value = y > tally_map # indices > ) ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
