Henry Rich wrote: > OK, the inverses of 9-12&o. are reasonable, as good as any. > But the inverses of _9-_12&o. should be, respectively, > > _9&o. _10&o. _11&o.@:- (or 0j_1&*) 0j_1&[EMAIL PROTECTED] >
Henry: Since _9&o. , _10&o. and _11&o. are 1-1 on the complex numbers, it makes sense to me to have their full inverses, as you indicate. For _12&o. , I think that it is intended to be restricted to the reals, in an Euler's formula context. expi=:_12&o. expi^:_1 expi 2 NB. OK: in principal domain 2 expi^:_1 expi 17 NB. real, outside principal domain _1.84956 expi^:_1 expi 1j1 NB. Not OK 1 Overall, I think these functions need a bit more explanation. Specifying principal domains for inverse purposes would go a long way. Best wishes, John ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
