+/&.:% 10 20 40 5.71429 I was too fast. You don't even need to parenthesize (+/).
--- Den tors 4/2/10 skrev Bo Jacoby <[email protected]>: > Fra: Bo Jacoby <[email protected]> > Emne: Re: [Jprogramming] A q for starters - composing without forking (% +/ %) > Til: "Programming forum" <[email protected]> > Dato: torsdag 4. februar 2010 08.33 > %&(+/)&:% 10 20 > 40 > 5.71429 > (+/)&.:% 10 20 40 > 5.71429 > > Welcome Alex. The catch is to parenthesize (+/). > > --- Den tors 4/2/10 skrev Alex Gian <[email protected]>: > > > Fra: Alex Gian <[email protected]> > > Emne: [Jprogramming] A q for starters - composing > without forking (% +/ %) > > Til: [email protected] > > Dato: torsdag 4. februar 2010 01.36 > > Hi - complete newbie to J here. > > Though I like what I've seen so far. > > > > Here's my starter question: > > I'd like to code the function that gives the inverse > of a > > sum of > > inverses (eg. like when calculating resistors in > parallel) > > > > It works fine if I just write it out as > > % +/ % 10 20 40 > > (ans 5.71429) > > > > However, if I try to make a function of it, > > invsuminv =. % +/ % > > it becomes a fork (I guess that _does_ make sense), > and > > just computes > > the "cross-sum" of the inverses, as if I'd typed > > (% +/ %) 10 20 40 > > 0.2 0.15 0.125 > > 0.15 0.1 > > 0.075 > > 0.125 0.075 0.05 > > > > How can I avoid this? I've tried all sorts of > combinations, > > using @ and > > & but can't seem to crack it. Obviously > something > > fundamental I'm not > > grasping. Any help appreciated. > > > > > > > > > > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > __________________________________________________ > Bruger du Yahoo!? > Er du træt af spam? Yahoo!Mail har den bedste > spambeskyttelse, der findes > http://dk.mail.yahoo.com > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > __________________________________________________ Bruger du Yahoo!? Er du træt af spam? Yahoo!Mail har den bedste spambeskyttelse, der findes http://dk.mail.yahoo.com ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
