I am not quite sure what you are saying, but (* _1 ^ >:)# does not give an alternating sign.
-- Raul On Sat, Sep 11, 2021 at 3:44 PM Hauke Rehr <hauke.r...@uni-jena.de> wrote: > > Okay, before anyone else wastes time on this: > I forgot the factorial, you’ll need to add a > ! or !@] or something. That doesn’t do it yet. > I’ll try to find a correct phrasing first. > > What I still find puzzling is that changing > the alt sign (* _1 ^ >:) (applied to # of a > list growing with the iterations) to replacing > +/ by -/ gave different results. > > But let’s see if that still holds once I get > the sequence right. > > > Am 11.09.21 um 21:33 schrieb Raul Miller: > > While I don't have a specific explanation (I have not looked closely > > enough), I was somewhat bemused by the consequences of executing: > > > > NXT1=: 4 : 'x nxt1 y [ echo x;y' > > PS1=: 0 +/@:((NXT1 ,^:(0 ~: [) ])^:_)~ ] > > (PS1 - ^.@>:)"0 % 2^>:i.5 > > > > Sums of alternating signed floating point numbers of similar magnitude > > have a tendency to lose precision. (And, values in the range of 1e_323 > > also tend to run into issues, if that matters.) > > > > Take care, > > > > -- > ---------------------- > mail written using NEO > neo-layout.org > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
