That was a good math lesson! I couldn't believe I hadn't noticed that a negative divided by a negative is always a negative. You used some cleveer ways of simplifying the expression. I liked how you Went outside the parentheses or were "thinking outside the box"
Linda -----Original Message----- From: programming-boun...@forums.jsoftware.com [mailto:programming-boun...@forums.jsoftware.com] On Behalf Of Bo Jacoby Sent: Monday, April 21, 2014 7:16 AM To: programm...@jsoftware.com Subject: Re: [Jprogramming] Logarithmic Mean Hi Linda. Translating from your version to mine: 5(13 :'(|x-y)%|(^.x)-^.y')20 NB. Linda's lm3 10.8202 5(13 :'(x-y)%(^.x)-^.y')20 NB. omitting '|' 10.8202 5*1(13 :'(x-y)%(^.x)-^.y')20%5 NB. homogeneity 10.8202 5*(13 :'(1-y)%(^.1)-^.y')20%5 NB. fix x=1 10.8202 5*(13 :'(<:y)%^.y')20%5 NB. (x%y) = (-x)%-y 10.8202 13 :'(<:y)%^.y' NB. tacit <: % ^. 5*(<:%^.)20%5 NB. check 10.8202 5(13 :'y* (<:%^.) x%y') 20 NB. linearity 10.8202 13 :'y* (<:%^.) x%y' NB. tacit ] * [: (<: % ^.) % 5(] * [: (<: % ^.) %)20 NB. check 10.8202 Den 11:17 mandag den 21. april 2014 skrev Linda Alvord <lindaalv...@verizon.net>: I should have gone to the original website a lot sooner. > > lm3=: 13 :'(|x-y)%|(^.x)-^.y' > 5 lm2 20 >10.8202 > > lm3 >([: | -) % [: | ([: ^. [) - [: ^. ] > > Now this agrees with Bo's shorter version.. > >Linda > >-----Original Message----- >From: programming-boun...@forums.jsoftware.com >[mailto:programming-boun...@forums.jsoftware.com] On Behalf Of Bo Jacoby >Sent: Monday, April 21, 2014 12:48 AM >To: programm...@jsoftware.com >Subject: Re: [Jprogramming] Logarithmic Mean > >Try this: > > l=. 13 : '(<:y)%^.y' > lm=. 13 : 'y*l x%y' f. NB. logarithmic mean > lm >] * [: (<: % ^.) % > 3 lm 3.000002 >3 > 3 lm 3.00002 >3.00001 > >Thanks. Bo. > > >Den 2:04 mandag den 21. april 2014 skrev Raul Miller ><rauldmil...@gmail.com>: > >On Sun, Apr 20, 2014 at 7:08 PM, Henry Rich <henryhr...@nc.rr.com> wrote: >>> More exact equality isn't enough - as you can see from the example, it >>> calculates a mean of 2.7 when 3 is the right answer. The problem there >is >>> roundoff error I expect. >> >>I doubt the numbers I am working with would have even 10 digits of >>accuracy, so I'm actually not too worried. >> >>Thanks, >> >> >>-- >>Raul >>---------------------------------------------------------------------- >>For information about J forums see http://www.jsoftware.com/forums.htm > >> >> >> >---------------------------------------------------------------------- >For information about J forums see http://www.jsoftware.com/forums.htm >---------------------------------------------------------------------- >For information about J forums see http://www.jsoftware.com/forums.htm > > > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
