my attempt at expressing them in J greeting =: '+#007';'&+5,670$6';'*';'%.+*2' o =: >./ q: ". > (, , [)&.>/ greeting o =: o + +`*:`%:`<:"0 , $&> |. greeting o (4 : '(+&x)&.(a.&i.)&.> y')"0 greeting
Am 24.12.20 um 14:05 schrieb emacstheviking: > Henry, > > What's the upper bound on that pre-allocated list, that's a good technique > actually. But what do I know? > My main issue was more the fact I couldn't see another way to do it but > both Raul and Clifford have shown me the way. > > Seasons greeting to all, I'd express that in J but... > > On Thu, 24 Dec 2020 at 13:01, Henry Rich <[email protected]> wrote: > >> i. 100 returns a section of a pre-allocated list, so it doesn't even >> have to generate anything. >> >> (? 100 $ y) is a smidgen slower than (100 ?@$ y) >> >> Henry Rich >> >> On 12/24/2020 7:37 AM, Raul Miller wrote: >>> Generating that list of numbers is trivial, compared to typical >>> language processing. >>> >>> Consider a classic "for" loop, which calls a function 100 times. Here, >>> you are also generating 100 numbers. It's true that they are not >>> stored in memory simultaneously, but you're also generating 100 stack >>> frames, one after another -- and the cost of constructing those is >>> significant. Writing to one memory location is less work than >>> populating a typical stack frame. >>> >>> Also, in terms of actual memory consumed -- unless you're up in the >>> megabytes, you aren't going to even notice it on modern machines. >>> >>> That said, if your concern is the *relevance* of the numbers, I'd go >>> with something like: >>> >>> 1,.~? 100 $ ,: 2 1024 768 >>> >>> Which, looking at what Cliff Reiter suggested, is basically the same >> concept. >>> >>> Good luck, >>> >> >> >> -- >> This email has been checked for viruses by AVG. >> https://www.avg.com >> >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm >> > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- ---------------------- mail written using NEO neo-layout.org ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
