scatter selection, transitive closure and state transition

Community Support
1

Hi,

Can anyone throw some light on how the features mentioned in the subject work ?
They are present since K2, but couldn’t find any documentation.

The old K online help just shows the syntax:

scatter selection    matrix’
transitive closure    vector/   vector\
state transition       matrix/  matrix   matrix’:

I’ve figured out how one case of state transition works, but that was trial and error.

Thanks,
Andras Pahi

2

Andras wrote:
“They are present since K2”

  1.  Are you saying that these features exist in k4 and in q?

  2.  Also in k5?

  3.  Can you post the source where you found the references to these features (for context)?

3

> 2)  Also in k5?
Sorry for the dumb question, what is k5?

4

The following post never made it to the group:

Hi,

1)  Are you saying that these features exist in k4 and in q?
Yes. When you switch to K mode in q, then they work.

2)  Also in k5?
I don’t know. k5 (kparc.com) is a moving target. I don’t have access to the executable.

3)  Can you post the source where you found the references to these features (for context)?
In K 2.9t (2001-03-12) and K 3.2 (2005-06-25) they are on the adverbs help page '
The script http://kx.com/a/k/examples/read.k uses state transition.

Regards,
Andras Pahi

5

Andras wrote:
“They are present since K2”

Yes. They are all super logical choices in retrospect given that juxtaposition denotes top-level indexing (@)

(but at the same time I think k2-3 users were not aware of these for quite a while)

6

Thank you for the examples and references!

Andras Pahi