cool, dgerund *:`^`(2&^)
----- Original Message ----- From: Raul Miller <[email protected]> To: Programming forum <[email protected]> Cc: Sent: Tuesday, November 3, 2015 5:05 PM Subject: Re: [Jprogramming] derivatives of a gerund Like this? dgerund=:3 :0"0 {.(y`:6 d.1)`'' ) r=:4 :0 dx=. dgerund x ddx=. dgerund dx NB. fill in the rest... ) Note that if you have verbs which can't be handled by d. you'll have to use a cover for d.1 which does what you need for those cases. Thanks, -- Raul On Tue, Nov 3, 2015 at 4:43 PM, David Lambert <[email protected]> wrote: > In algebraic notation I have a parametric curve > x=u(t), y=v(t), z=v(t) > and need radius_of_curvature(t) > > Would like the verb r taking a gerund argument, > u`v`w r t > but requires first and second derivatives. > > In LaTeX linear notation, with \times representing cross product, curvature > is > \[\frac{\|\vec{r'}\|^3}{\|\vec{r'}\times\vec{r''}\|}\] > > This being messy, derivatives of a gerund packed back into a gerund would be > great, then `:0 would generate the vectors. > > Thanks, Dave. > ---------------------------------------------------------------------- > 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
