Here's a breakdown of how I wrote that.
First, consider how oblique works:
</. i.3 4
+-+---+-----+-----+----+--+
|0|1 4|2 5 8|3 6 9|7 10|11|
+-+---+-----+-----+----+--+
It captures diagonals from a matrix. And, also, it's J verb is
spelled the same as key -- so it would make sense if they were
related. So, what would the key be?
This looks promising:
(i.3) +/ i.4
0 1 2 3
1 2 3 4
2 3 4 5
So I am going to want to insert a verb between the first two elements
of the shape.
3 +/&i. 4
0 1 2 3
1 2 3 4
2 3 4 5
+/&i./ 3 4
0 1 2 3
1 2 3 4
2 3 4 5
Now I just need to ravel them and put the pieces together. Oh, and I
also need to merge the first two dimensions of y so that key can work
properly:
(,+/&i./ 2{. $y) u key ,/y
This works, but if I left it like this, I would have to add a comment
about how it does not work right when the argument (y) has less than
two dimensions. 2 {. $y will fill in 0s for those dimensions, and I
want 1s. So I added a couple 1s so that those cases would work right.
--
Raul
On Fri, Dec 9, 2011 at 12:18 PM, Linda Alvord <[email protected]> wrote:
> Where did you get this. Is there some way that you capture code like this or
> do you just write it yourself?
>
> oblique=:1 :0
> (,+/&i./ 2{.1 1,~$y) u key ,/y
> )
>
> Thanks in advance.
>
> Linda
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Raul Miller
> Sent: Friday, December 09, 2011 11:09 AM
> To: Programming forum
> Subject: Re: [Jprogramming] Oblique Road to Success!
>
> On Fri, Dec 9, 2011 at 10:46 AM, Linda Alvord <[email protected]> wrote:
>> b=:5 3 5
>> Either definition has only one argument so isn't the function oblique rather
>> than key? So Ric has taken the "Oblique oad To Success!". One wonders if it
>> is faster than the other one.
>
> My previous post about equivalents to /. was confused.
>
> /.~ uses key
> /. without ~ and using only one argument is oblique
>
> key=:1 :0
> :
> (=x) u@#"1 _ y
> )
>
> oblique=:1 :0
> (,+/&i./ 2{.1 1,~$y) u key ,/y
> )
>
> FYI,
>
> --
> Raul
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