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
