That's a good point. That ambiguity you called out would indeed be a
problem.
Meanwhile, the functionality which I was reaching for could be expressed as:
(10 $ 2{. 1) # i. 10
0 2 4 6 8
or, equivalently:
2 (i.@] #~ ] $ [ {. 1:) 10
0 2 4 6 8
Or, better yet:
2 (i.@] #~ ] $ [ {. 1:) 11
0 2 4 6 8 10
But what's a word to describe this issue of step size? I'd like to use it
with thru:
thru=: <./ + i.@(+ *)@-~
0 thru 10
0 1 2 3 4 5 6 7 8 9 10
Perhaps:
stepsize=: ] #~ $@] $ [ {. 1:
2 stepsize 0 thru 10
0 2 4 6 8 10
2 stepsize 10 thru _2
10 8 6 4 2 0 _2
Of course, there's a limitation here. If I ask for a step size which clips
off the ending point, I will not see it in my results. And, there's nothing
really wrong with using i. directly. Still, this kind of thing can be fun
to play with.
Thanks,
--
Raul
On Fri, Mar 21, 2014 at 9:11 AM, Pascal Jasmin <[email protected]>wrote:
> exploring i: with j parameters is very impressive.
>
> it creates equal intervals from -xj to xj.
>
> even jy will include 0 in the interval list.
>
> i: 10j3
> _10 _3.33333 3.33333 10
> i: 10j4
> _10 _5 0 5 10
>
> I can understand not including a i. definition, bc if you wanted
>
> 0 5 10
>
>
> should you call i. 10j2 or i. 10j4 ?
>
> The latter keeps the mirror properties of i. and i:, but the result is 2
> intervals instead of 4. It doesn't seem overwhelmingly difficult to filter
> out the results of i: to get what you want. Odd jy params are interesting,
> and might be lost with a definition for i. that strives for conceptual
> simplicity relative to its y arguments rather than to i: reference.
>
>
> ----- Original Message -----
> From: Raul Miller <[email protected]>
> To: Programming forum <[email protected]>
> Cc:
> Sent: Friday, March 21, 2014 8:06:23 AM
> Subject: Re: [Jprogramming] A curious omission
>
> I was trying to draw a contrast between the domains of i. and i:
>
> Also, my use of !. (fit) was not meant to be ! (out of). I was talking
> about potential language enhancements (which should focus on taking error
> cases and re-using them for something that makes sense) and not about using
> the language as it is now. Perhaps I should have used the chat forum, given
> the subject matter?
>
> Thanks,
>
> --
> Raul
>
>
>
> On Fri, Mar 21, 2014 at 5:09 AM, Linda Alvord <[email protected]
> >wrote:
>
> > Perhaps you meant:
> >
> > i:2!10
> > _45 _44 _43 _42 _41 _40 _39 _38 _37 _36 _35 _34 _33 _32 _31 _30 _29 _28
> _27
> > _26 _25 _24 _23 _22 _21 _20 _19 _18 _17 _16 _15 _14 _13 _12 _11 _10 _9 _8
> > _7
> > _6 _5 _4 _3 _2 _1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
> > 22
> > 23 24 25 26 27 28 29 30 31...
> >
> > Linda
> > --
> > ---Original Message-----
> > From: [email protected]
> > [mailto:[email protected]] On Behalf Of Raul
> Miller
> > Sent: Friday, March 21, 2014 2:22 AM
> > To: Programming forum
> > Subject: [Jprogramming] A curious omission
> >
> > i: 10j2
> > _10 0 10
> > i. 10j2
> > |domain error
> >
> > Not quite sure why we can use complex numbers with i: but not i.
> >
> > Of course it might also be useful to specify the step size instead of the
> > number of steps. But !. could be used for that:
> >
> > i.!.2]10
> >
> > |domain error
> >
> >
> > Curious...
> >
> >
> > --
> >
> > 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
>
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
