In Sean's case I'd use:

100 3 ?@$ 2 100 100

if a verb is needed for x numbers with specs y I'd use:

stargen=: (, #) ?@$ ]

Don't worry about feeling stupid, I did so for a while too, and it goes
away. Not because you know everything, but because you realise J is really
deep, and there's so many nooks and crannies to discover (and rediscover,
once forgotten again). Better start enjoying it, it's a long trip ;) and
very rewarding. Aside of that, there's plenty of help to be gotten, both in
documentation and the very knowledgable and friendly community (on this
mailing list, but also on stackoverflow.com[0]). For a beginner, I would
really recommend reading the books (e.g. Learning J[1], and JforC [2]), the
labs (after installing the addon labs/labs, in the jqt menu
help>studio>labs).

Good luck with your J journey, and all the best for the festive season.

Jan-Pieter

[0]: https://stackoverflow.com/questions/tagged/j
[1]: https://www.jsoftware.com/help/learning/contents.htm
[2]: https://www.jsoftware.com/help/jforc/contents.htm

On Thu, Dec 24, 2020, 14:01 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,
> >
>
>
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