That is a dot product, a scalar zero on the left and a matrix on the right. If you follow the rules of a dot product the scalar zero is treated as (1 2$0) giving the result.
On Thu, May 5, 2016 at 3:54 PM, Geoff Canyon <[email protected]> wrote: > So there are a few learning opportunities here -- euphemism for things I > don't understand ;-) > > I get how adding 0 = transforms the modulo results into a 1 for "divisible" > and 0 for "not divisible": > > 3 5 (0 = (|/ i.)) 20 > > 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 0 1 0 > > 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 > > > But I'm not seeing how this combines those results with an OR: > > > 3 5 (0 +./ .= (|/ i.)) 20 > > 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 0 0 1 0 > > > Maybe I'm just not seeing how the forks/hooks resolve themselves? I seem to > recall there was a command to get J to box a command to show how that flow > works, but I don't remember it. Or maybe that's not it at all and I'm just > confused. > > > thx > > > gc > > On Wed, May 4, 2016 at 11:35 PM, Raul Miller <[email protected]> > wrote: > > > On Wed, May 4, 2016 at 10:35 PM, Geoff Canyon <[email protected]> wrote: > > > So I tried to write code to solve the general case of Project Euler > > problem > > > 1. The problem given is to find the sum of all the positive integers > less > > > than 1000 that are divisible by 3 or 5. Obviously the specific case is > > > highly optimizable. But I wanted to solve the general, with any number > of > > > divisors and any upper limit. > > > > ... > > > Here's the code. As always, I suck at J, so improvements/suggestions > are > > > welcome. > > > > > > pe1 =: +/@(([:i.]) * 1&-@(0&i.)@*/"1@|:@(|"0 1 i.)) > > > > Maybe: > > pe1=: [:+/@I. 0 +./ .= (|/ i.) > > > > ? > > > > Assuming email anti-spam bots do not eat my line for including an @ > > character. Maybe, instead: > > > > pe1=: [:+/ [:I. 0 +./ .= (|/ i.) > > > > ... > > > > -- > > Raul > > ---------------------------------------------------------------------- > > 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
