Or, more specifically, = is comparing atoms (the things that go into arrays, which includes everything in a box - including the shape of things in the box).
Thanks, -- Raul On Wed, Dec 20, 2017 at 12:48 AM, Devon McCormick <[email protected]> wrote: > Or, to put it another way, equality (=) which compares values is different > from equivalence (-:) which accounts for shape as well. > > On Wed, Dec 20, 2017 at 12:35 AM, bill lam <[email protected]> wrote: > >> = is rank 0 >> -: is rank infinity >> >> Try 0= 1$0 and 0-: 1$0 >> and note the shape of results >> >> On Dec 20, 2017 1:16 PM, "Dabrowski, Andrew John" <[email protected]> >> wrote: >> >> > Here's my latest exasperation. >> > >> > zero =: < (1$0) >> > >> > zero >> > >> > ┌─┐ >> > >> > │0│ >> > >> > └─┘ >> > >> > > zero >> > >> > 0 >> > >> > $ > zero >> > >> > 1 >> > >> > zero = <0 >> > >> > 0 >> > >> > (>zero) = 0 >> > >> > 1 >> > >> > >> > Why in God's name does J consider a singleton list 0 equal to the scalar >> > 0 but consider the boxed versions of each distinct? >> > ---------------------------------------------------------------------- >> > For information about J forums see http://www.jsoftware.com/forums.htm >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> > > > > -- > > Devon McCormick, CFA > > Quantitative Consultant > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
