Aha! except! I had no idea that from '{' had such a useful option.
(<<< 1 4 5 7) { 2 3 5 7 11 14 56 78 95
2 5 7 56 95 NB. Cool!
If i wanted to make a dyadic verb 'ex' that worked just like the above, how
could I do that?
1 4 5 7 ex 2 3 5 7 11 14 56 78 95
2 5 7 56 95
ex =: [:@<@<@<[{]
2 3 ex 1 2 3 4 5
|index error: ex
| 2 3 ex 1 2 3 4 5
Nope! that didn't work.
Skip
Skip Cave
Cave Consulting LLC
On Tue, Nov 8, 2016 at 12:32 AM, Raul Miller <[email protected]> wrote:
> 2 { 2 3 5 7 11
> 5
> (<<<2) { 2 3 5 7 11
> 2 3 7 11
>
> Look for the word "except" at http://www.jsoftware.com/help/
> dictionary/d520.htm
>
> Thanks,
>
> --
> Raul
>
>
> On Tue, Nov 8, 2016 at 12:17 AM, Skip Cave <[email protected]>
> wrote:
> > Nice! Xiao-Yong's verb does exactly what I need.
> >
> > f=:(] +:@{`[`]} <@<@<@]{[)"_ 0 [:I.2=/\]
> >
> > t =. 1 2 2 4 1 5 3 4 4 4 2 3 3
> >
> > f t
> >
> > 1 4 4 1 5 3 4 4 4 2 3 3
> >
> > 1 2 2 4 1 5 3 8 4 2 3 3
> >
> > 1 2 2 4 1 5 3 4 8 2 3 3
> >
> > 1 2 2 4 1 5 3 4 4 4 2 6
> >
> >
> > I can understand [:I.2=/\]. Using I. is the perfect way to find the
> > indices of the dups. However, the rest of that big infinite-rank tacit
> > expression to the left must generate each of the reduced items. I'm
> totally
> > lost trying to figure that out. Why the zero? Why three <@? I thought [
> > represented a left argument, but there isn't a left argument. Any help is
> > appreciated.
> >
> >
> > Skip
> >
> > Skip Cave
> > Cave Consulting LLC
> >
> > On Mon, Nov 7, 2016 at 10:25 PM, Xiao-Yong Jin <[email protected]>
> > wrote:
> >
> >> So you probably just need this:
> >> f=:(] +:@{`[`]} <@<@<@]{[)"_ 0 [:I.2=/\]
> >> or really the adverb
> >> a=:1 :'u@(] +:@{`[`]} <@<@<@]{[)"_ 0 [:I.2=/\]'
> >>
> >> You may find different solutions if you abstract your problem
> differently.
> >>
> >> > On Nov 7, 2016, at 9:30 PM, Skip Cave <[email protected]>
> wrote:
> >> >
> >> > Very interesting. Quite a difference in space and time usage, not to
> >> > mention length of the tacit code.
> >> >
> >> > For my application, a rank 0 or 1 in the summed result isn't all that
> >> > critical. As long as the contents of each box can be used in further
> >> > arithmetic and Boolean operations (e.g. it's not text), then I'm ok.
> >> >
> >> >
> >> > It looks like nouns with ranks 0 or 1 don't affect the outcome of
> simple
> >> > arithmetic operations:
> >> >
> >> >
> >> > ($4);($,4);(4=,4);(1+4);(1+,4);((1+4)=1+,4);($1+4);($1+,4)
> >> >
> >> > ┌┬─┬─┬─┬─┬─┬┬─┐
> >> >
> >> > ││1│1│5│5│1││1│
> >> >
> >> > └┴─┴─┴─┴─┴─┴┴─┘
> >> >
> >> > The only time the difference becomes an issue:
> >> >
> >> > ($4)=($,4)
> >> >
> >> > |length error
> >> >
> >> > | ($4) =($,4)
> >> > But I don't care about this.
> >> >
> >> > Actually, Mike Day spotted what I was really trying to attempt.
> >> > The original starting vector is:
> >> >
> >> > n =: 1 2 2 4 1 5 3 4 4 4 2 3 3
> >> >
> >> > Then I box at each possible pair of integers using an infix
> >> sliding-window
> >> > on each pair of integers. This sliding box scheme was just to identify
> >> all
> >> > the duped pairs in the original vector.
> >> >
> >> > ]N =: 2<\pp
> >> >
> >> > ┌───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┬───┐
> >> >
> >> > │1 2│2 2│2 4│4 1│1 5│5 3│3 4│4 4│4 4│4 2│2 3│3 3│
> >> >
> >> > └───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┴───┘
> >> >
> >> >
> >> > What I ultimately wanted is a verb that will replace the duped pairs
> in
> >> the
> >> > *original* un-boxed vector, one at a time:
> >> >
> >> > n =: 1 2 2 4 1 5 3 4 4 4 2 3 3
> >> >
> >> > f n
> >> >
> >> > 1 4 4 1 5 3 4 4 4 2 3 3
> >> >
> >> > 1 2 2 4 1 5 3 8 4 2 3 3
> >> >
> >> > 1 2 2 4 1 5 3 4 8 2 3 3
> >> >
> >> > 1 2 2 4 1 5 3 4 4 4 2 6
> >> >
> >> > Of course, the final row lengths will be one shorter that the original
> >> row
> >> > length.
> >> >
> >> > Skip
> >> > ------------------------------------------------------------
> ----------
> >> > For information about J forums see http://www.jsoftware.com/
> forums.htm
> >>
> >> ----------------------------------------------------------------------
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> >>
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