I like the atan2 suggested by Tom. 13.03.2014, в 5:17, EelVex <[email protected]> написал(а):
> Isn't > > atan2 =: 12&o.@j./~ > > a very good candidate for inclusion in math/misc/trig.ijs ? > > > On Wed, Mar 12, 2014 at 4:07 AM, Tom Arneson <[email protected]> wrote: > >> The circle verb o. with 12 as the left argument >> >> NB. radian to degree >> r2d=: 180p_1*[ >> >> atan2=: 12&o. >> >> [r=. atan2 0j0 1j1 0j1 _1j1 _1j0 _1j_1 0j_1 1j_1 1j0 >> 0 0.785398 1.5708 2.35619 3.14159 _2.35619 _1.5708 _0.785398 0 >> >> r2d r >> 0 45 90 135 180 _135 _90 _45 0 >> >> 360|r2d r >> 0 45 90 135 180 225 270 315 0 >> >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]] On Behalf Of Raul Miller >> Sent: Tuesday, March 11, 2014 19:00 >> To: Programming forum >> Subject: Re: [Jprogramming] atan2 ? >> >> This might be what you are looking for? >> atan2trivial=: _3 o. %~ >> atan2=: 0 { [: +. [: r.^:_1 j. >> >> For the principal domain, atan2trivial matches atan2 >> 1 (atan2trivial -: atan2) 2 >> 1 >> >> However, atan2 can distinguish direction when x=0 >> 0 atan2 1 >> 1.5708 >> 0 atan2 _1 >> _1.5708 >> >> I'd like more test cases, though. I've not been doing much trig recently, >> and it's possible I made a mistake. >> >> Maybe someone who has been working with this kind of math can judge from >> what viewmat displays? >> >> require 'viewmat' >> viewmat atan2"0/~ i:100 >> >> Thanks, >> >> -- >> Raul >> >> >> >> >> On Tue, Mar 11, 2014 at 7:05 PM, EelVex <[email protected]> wrote: >> >>> Is there an atan2 anywhere in some library? >>> >>> If not maybe we could add it? >>> >>> A simple start could be: >>> atan2 =: +:@(_3&o.)@([ %~ ] -~ +/&.:*:) >>> ---------------------------------------------------------------------- >>> 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
