Talk:Diophantine linear system solving

From Rosetta Code
Revision as of 15:44, 26 December 2021 by Petelomax (talk | contribs) (→‎Totally lost: struckout "right now")

Totally lost

Some questions:
What does any of this actually mean?
What is a basis?
What is the standard basis?
What is a vector space?
What is the dimension of the vector space?
What is linear independence?
What is spanning property?
What is a spanning set?
What is a polynomial ring?
What is a monomial?
What is a monomial basis?
What is the Steinitz exchange lemma?
What is the axiom of choice?
What is the ultrafilter lemma?
What is the dimension theory?

I think you can see where I'm going with this, and I'm not even halfway through the first of, I dunno, 30,000 wikipedia pages I would have to read.

Let's try this: what does this actually mean?

2  1| 2
6  5| 2
7  6| 2

==>

P | Hnf
  1 -1  0 |  1  1  1  0
 -1  2 -0 | -0  4  5 -0
 -2  2  1 |  0  0  0  1  -solution
loop 7

I have a very vague grasp of what the input is, but the output is pure gibberish, and obviously "Transformation matrix P (left) and the Hermite normal form" elicits qs as above.

Detailed step-by-step inner workings of all 21 puzzles might be a start... --Pete Lomax (talk) 22:24, 24 December 2021 (UTC)

Sorry Pete, this task wasn't intended to swamp you in some murky math morass.
Let me reflect on this. I have a few busy days ahead, will be back sometime after Xmas.
But for now: if more people find this task...objectionable, it probably doesn't belong on RC after all. --M.C., Udo e. (talk)

Thanks, I have slowly figured a couple of things out. That example means, I think, solve {2a+b=2, 6a+5b=2, 7a+6b=2} ==> the answer, from (-2 2)*-1, is {a=2,b=-2}. I was thinking (and about to say) that a proper set of unit tests on Reduce() would help, but actually what I think I really need right now is unit tests (/detailed examples) on Swop(), especially with what it is trying to do to d[], so I can properly visualise (and maybe even understand) it. --Pete Lomax (talk) 16:40, 25 December 2021 (UTC)

Deserves to be on rc

Regarding objectional/belong, this task has more merit than 9/10 tasks that get added to rc. I won't deny there was a little (and irrelevant) grumpage (sorry), but that was much more about timing you could not possibly have known about. If a task author wants to see an algorithm in different programming languages, it belongs on rc, and that want should be incentive enough to take some extra trouble to explain it in layman terms. From my point of view I'd like to know more about how this might be used/prove useful in some future (non-rc) project, and that requires my understanding it well enough to debug and/or extend it. Despite now having posted a Phix entry, I don't remotely feel I'm done with this task yet, and it remains on my watchlist eagerly awaiting your updates. --Pete Lomax (talk) 15:01, 26 December 2021 (UTC)