I should note that your example connection matrix does not seem to
match the oid, nid values you displayed.
OID=: 1 9 6 2 10 7 3 11 4
NID=: 2 10 7 3 11 12 4 8 5
Here's the connection matrix I see represented:
]CM=: 1 (<:OID,.NID)} 0$~,~>./OID,NID
0 1 0 0 0 0 0 0 0 0 0 0
0 0 1 0 0 0 0 0 0 0 0 0
0 0 0 1 0 0 0 0 0 0 0 0
0 0 0 0 1 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 1 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 1
0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 1 0 0
0 0 0 0 0 0 0 0 0 0 1 0
0 0 0 0 0 0 0 1 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
Note that I am using a recent J version here. In older versions of J,
that would have to be 1 (<"1<:OID,.NID)} 0$~,~>./OID,NID
Anyways, its transitive closure would be:
(+. +./ .*~)^:_ CM
0 1 1 1 1 0 0 0 0 0 0 0
0 0 1 1 1 0 0 0 0 0 0 0
0 0 0 1 1 0 0 0 0 0 0 0
0 0 0 0 1 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 1 0 0 0 0 1
0 0 0 0 0 0 0 0 0 0 0 1
0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 1 0 1 1 0
0 0 0 0 0 0 0 1 0 0 1 0
0 0 0 0 0 0 0 1 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
But that does not match your suggested grouping operation (foo), so
let's assume that connections work both ways:
]TC=: (+. +./ .*~)^:_ CM+.|:CM
1 1 1 1 1 0 0 0 0 0 0 0
1 1 1 1 1 0 0 0 0 0 0 0
1 1 1 1 1 0 0 0 0 0 0 0
1 1 1 1 1 0 0 0 0 0 0 0
1 1 1 1 1 0 0 0 0 0 0 0
0 0 0 0 0 1 1 0 0 0 0 1
0 0 0 0 0 1 1 0 0 0 0 1
0 0 0 0 0 0 0 1 1 1 1 0
0 0 0 0 0 0 0 1 1 1 1 0
0 0 0 0 0 0 0 1 1 1 1 0
0 0 0 0 0 0 0 1 1 1 1 0
0 0 0 0 0 1 1 0 0 0 0 1
That gives us something close to the grouping you asked for:
TC </. 1+i.#TC
+---------+------+---------+
|1 2 3 4 5|6 7 12|8 9 10 11|
+---------+------+---------+
The ordering here is different, but if that's important we could try to fix it:
(/: {:@>) TC </. 1+i.#TC
+---------+---------+------+
|1 2 3 4 5|8 9 10 11|6 7 12|
+---------+---------+------+
I hope this helps,
--
Raul
On Fri, Sep 3, 2021 at 11:21 AM Pablo Landherr <pablo.landh...@gmail.com> wrote:
>
> I want to group items that are linked to each other. I tried to use some
> kind of connection matrix
>
> nid =/ oid NB. an example
>
> 0 0 0 1 0 0 0 0 0
>
> 0 0 0 0 1 0 0 0 0
>
> 0 0 0 0 0 1 0 0 0
>
> 0 0 0 0 0 0 1 0 0
>
> 0 0 0 0 0 0 0 1 0
>
> 0 0 0 0 0 0 0 0 0
>
> 0 0 0 0 0 0 0 0 1
>
> 0 0 0 0 0 0 0 0 0
>
> 0 0 0 0 0 0 0 0 0
>
>
> to group items linked to each other but I can't figure out how to proceed
> from there. I'm hoping someone has a trick in their toolbox to share with
> me.
>
> oid is the first number of all connections and nid is the second number. So
> in this example 6 is connected to 7, 7 is connected to 12 and 12 has no
> further connection. What should foo be?
>
>
> oid,.nid
>
> 1 2
>
> 9 10
>
> 6 7
>
> 2 3
>
> 10 11
>
> 7 12
>
> 3 4
>
> 11 8
>
> 4 5
>
> oid foo nid
>
> ┌─────────┬─────────┬──────┐
>
> │1 2 3 4 5│9 10 11 8│6 7 12│
>
> └─────────┴─────────┴──────┘
>
>
> Thank you,
>
> Pablo
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