This is basically what I was looking for and is quite nice 2010/12/27 bob therriault <bobtherria...@mac.com>
> A bit more elegant solution: > > g2=:((>:@:])^:([>f@:])^:_)~ > > A do while loop. The trick here is that the ~ adverb allows me to use two > arguments (x) and (y) when I only supply (y). The (x) can be used as a > reference and I just increment and test until f(x) > y > > ts 'g2 6037' > 0.106917 371328 > > g=: i.~ f"0@:i.@:+: > > ts 'g 6037' > 12.5618 869376 > > Cheers, bob > > On 2010-12-26, at 3:38 PM, bob therriault wrote: > > > Whoops, too much turkey!! > > > > I meant to say that: > > g=: i.~ f"0@:i.@:+: > > g 75 > > 87 > > > > Cheers, bob > > > > On 2010-12-26, at 1:48 PM, bob therriault wrote: > > > >> Hi Björn, > >> > >> This is a bit brute force but it seems to work. > >> g=: i.~ f"0@:i.@:+: > >> g 87 > >> 75 > >> > >> Essentially applying f to a list up to twice the argument (y) and > returning the index (x) of the first spot f(x)=y > >> > >> Cheers, bob > >> > >> ps. I believe your original f can also be written as: > >> f1=: [: # i. -./ 2 3 ^~ i. > >> > >> On 2010-12-26, at 11:47 AM, Björn Helgason wrote: > >> > >>> I have a small task that looks like this > >>> > >>> f=: [: # i. -. (2 ^~ i.) , 3 ^~ i. > >>> f 87 > >>> 75 > >>> > >>> I want to use tacit to find what number gives me 75 numbers (the answer > >>> being 87) > >>> > >>> Could be asking what argument y do I need to find x numbers according > to the > >>> formula above > >>> > >>> -- > >>> Björn Helgason, Verkfræðingur > >>> Fornustekkum II > >>> 781 Hornafirði, > >>> t-póst: gos...@gmail.com > >>> gsm: +3546985532 > >>> sími: +3544781286 > >>> http://groups.google.com/group/J-Programming > >>> > >>> > >>> Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari > einfaldleikans > >>> > >>> góður kennari getur stigið á tær án þess að glansinn fari af skónum > >>> /|_ .-----------------------------------. > >>> ,' .\ / | Með léttri lund verður | > >>> ,--' _,' | Dagurinn í dag | > >>> / / | Enn betri en gærdagurinn | > >>> ( -. | `-----------------------------------' > >>> | ) | (\_ _/) > >>> (`-. '--.) (='.'=) ♖♘♗♕♔♙ > >>> `. )----' (")_(") ☃☠ > >>> ---------------------------------------------------------------------- > >>> 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 > -- Björn Helgason, Verkfræðingur Fornustekkum II 781 Hornafirði, t-póst: gos...@gmail.com gsm: +3546985532 sími: +3544781286 http://groups.google.com/group/J-Programming Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari einfaldleikans góður kennari getur stigið á tær án þess að glansinn fari af skónum /|_ .-----------------------------------. ,' .\ / | Með léttri lund verður | ,--' _,' | Dagurinn í dag | / / | Enn betri en gærdagurinn | ( -. | `-----------------------------------' | ) | (\_ _/) (`-. '--.) (='.'=) ♖♘♗♕♔♙ `. )----' (")_(") ☃☠ ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
