a=. 2 3 4 5 6 7 8 9 10 +/ .(*"4)&i. 7 8 9 10
b=. ((*/2 3 4 5),6,(*/7 8 9 10)) +/ .(*"1)&i. */7 8 9 10
a-:b
0
That said, it might be interesting to replace +/ with +/@,
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Raul
On Mon, May 30, 2022 at 2:25 AM Elijah Stone wrote:
>
> That's reinforcing my point--there are no more than t
On Mon, 30 May 2022, Elijah Stone wrote:
The equivalent to 'rank', then, would specify a 'root' node within each array.
(The rank conjunction, that is.)
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Einstein Summation Notation
Not familiar with this specifically, but named axes have been suggested, and I
was discussing them with somebody recently. I think they are an interesting
idea, but do not like them; I think they are either noncompositional and
error-prone or else so incapable as
Thanks for the links to those postings by Roger and Marshall, Elijah.
During the episode Marshall does refer to Einstein Summation Notation as a
system that names the axes. https://en.wikipedia.org/wiki/Einstein_notation
The other multidimensional primitives that I can think of are Shift and Ro
That's reinforcing my point--there are no more than three significant axes
there.
a=. 2 3 4 5 6 7 8 9 10 +/ .(*"4)&i. 7 8 9 10
b=. ((*/2 3 4 5),6,(*/7 8 9 10)) +/ .(*"1)&i. */7 8 9 10
a -:&, b
1
On Mon, 30 May 2022, Raul Miller wrote:
> On Mon, May 30, 2022 at 1:31 AM Elijah Stone wr
On Mon, May 30, 2022 at 1:31 AM Elijah Stone wrote:
> Rank is about projecting a 2- or 3-dimensional structure onto
> multidimensional arrays.
Those are common cases, but the concepts behind the notation do
support operations like:
$2 3 4 5 6 7 8 9 10 +/ .(*"4)&i. 7 8 9 10
2 3 4 5 7 8 9 10
I only skimmed the transcript. I have two things to add:
1. Two postings by Marshall and Roger:
http://www.jsoftware.com/pipermail/programming/2020-February/054999.html
http://www.jsoftware.com/pipermail/programming/2020-February/055012.html
2. Rank is not, on the whole and for the most part
A bit late this week because I was travelling, but here is the most recent
ArrayCast episode on Rank and Leading Axis theory.
https://www.arraycast.com/episodes/episode28-rank-and-leading-axis
Cheers, bob
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