Opened 5 years ago

Closed 5 years ago

#16500 closed enhancement (fixed)

New recursive constructions of Orthogonal Arrays

Reported by: ncohen Owned by:
Priority: major Milestone: sage-6.3
Component: combinatorial designs Keywords:
Cc: vdelecroix, knsam Merged in:
Authors: Nathann Cohen Reviewers: Vincent Delecroix
Report Upstream: N/A Work issues:
Branch: 697dd0c (Commits) Commit: 697dd0ca8284485897b051015af74b385c345fb4
Dependencies: #16499 Stopgaps:

Description

Here they are ! They have been sitting on my HD for a long time :-P

Nathann

Change History (29)

comment:1 Changed 5 years ago by ncohen

  • Status changed from new to needs_review

comment:2 Changed 5 years ago by ncohen

  • Branch set to u/ncohen/16500

comment:3 Changed 5 years ago by git

  • Commit set to 70f7046fea49d3ae47cfd3670a9c53f34791e462

Branch pushed to git repo; I updated commit sha1. New commits:

004833atrac #16347: Wilson's construction with two truncated groups
f5069f0trac #16347: Merged with 6.3.beta4
f182d36trac #16499: Cheap speedup in the OA recursive constructions
70f7046trac #16500: New recursive constructions of Orthogonal Arrays

comment:4 follow-up: Changed 5 years ago by vdelecroix

  • Status changed from needs_review to needs_info

EDIT: deleted comment as I messed up ticket numbers...

Last edited 5 years ago by vdelecroix (previous) (diff)

comment:5 in reply to: ↑ 4 Changed 5 years ago by vdelecroix

(Replying to comment:4) sorry, this comment was for #16430. Not this one!!

comment:6 Changed 5 years ago by vdelecroix

  • Status changed from needs_info to needs_review

comment:7 Changed 5 years ago by ncohen

Rebased on top of #16499. But....

sage -t --long latin_squares.py
    [40 tests, 35.08 s]

T_T

Nathann

comment:8 Changed 5 years ago by git

  • Commit changed from 70f7046fea49d3ae47cfd3670a9c53f34791e462 to 770a28da24236a2b13f905eab3d827e0fbfe34d8

Branch pushed to git repo; I updated commit sha1. This was a forced push. Last 10 new commits:

0fa89d5trac #16347: Wilson's construction with two truncated groups
828ff22trac #16437: cut the branches in W. dec. with two trunc. blocks
8ebd21btrac #16347: use is_sum_of_squares_pyx instead of two_squares
0175134trac #16347: doc + simplifications
9ff5062trac #16423: Table of MOLS from the handbook and comparison with Sage
e64be98trac #16423: tiny code improvement and alignment
e948cf6trac #16423: Aligning the alignment
0a7d853trac #16423: Broken doctests
b329351trac #16499: Cheap speedup in the OA recursive constructions
770a28dtrac #16500: New recursive constructions of Orthogonal Arrays

comment:9 follow-up: Changed 5 years ago by vdelecroix

Hi Nathann,

Stupid questions to start:

  • It would be nice to have references! You provide [AC07]_ for construction_3_4 but that's all.
  • Why you did not move product, one_truncated_group and two_trucated_group in the recursive construction?
  • Why not put the cache only for find_recursive_construction? (less cached function and less function calls)

Vicent

comment:10 in reply to: ↑ 9 ; follow-up: Changed 5 years ago by ncohen

Yo !

I updated the "find" functions a bit. Nothing smart, just common sense, and the MOLS_table function is fast again. Yeepeeeeeeeeee !!! :-P

  • It would be nice to have references! You provide [AC07]_ for construction_3_4 but that's all.

Ahahahah. I had nothing else :-P

I tried to reverse-engineer the construction from the theorem's claim, and when I was not able too I asked Julian R. Abel for a hint. This being said, the explanations I give in the docstring are more or less like a proof.

  • Why you did not move product, one_truncated_group and two_trucated_group in the recursive construction?

Because I thought that it would be abusing your kindness. I waste my health implementing those things, but I still try to makes patches somehow readable so that reviewing them will not be hell for you. I can add a commit for that if you don't mind. As I told you by email, "this is in the plan" :-P

  • Why not put the cache only for find_recursive_construction? (less cached function and less function calls)

Because this function returns both OA and True/False answers. The find_* functions I cached only return immutable stuff.

Nathann

comment:11 Changed 5 years ago by git

  • Commit changed from 770a28da24236a2b13f905eab3d827e0fbfe34d8 to a67c04f13bd0aa2b46e6998d2b996437f342470c

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

a67c04ftrac #16500: New recursive constructions of Orthogonal Arrays

comment:12 in reply to: ↑ 10 ; follow-up: Changed 5 years ago by vdelecroix

Replying to ncohen:

  • Why you did not move product, one_truncated_group and two_trucated_group in the recursive construction?

Because I thought that it would be abusing your kindness. I waste my health implementing those things, but I still try to makes patches somehow readable so that reviewing them will not be hell for you. I can add a commit for that if you don't mind. As I told you by email, "this is in the plan" :-P

Ok. Will see that later. I postponed to #16535 if you agree.

  • Why not put the cache only for find_recursive_construction? (less cached function and less function calls)

Because this function returns both OA and True/False answers. The find_* functions I cached only return immutable stuff.

But why not having orthogonal_array implements the three lines that are right now in find_recursive_construction? My main concern is about readability. I would prefer

@cached_method
def find_recursive_construction(k,n):
    for find_c in [find_construction_3_3,
                   find_construction_3_4,
                   find_construction_3_5,
                   find_construction_3_6]:
        res = find_c(k,n)
        if res: return res

That way:

  • you still have the freedom to update find_recursive_construction without touching orthogonal_array
  • you keep an eye on who did what with the cache
  • you perform the work of adapting your answer only in orthogonal_array
  • if you changed your mind about the syntax existence=True and such you will not have to touch to find_recursive_construction
  • the file orthogonal_array_recursive.py will look like a "dynamical" database in the very same way that database.py is a static one

Vincent

comment:13 in reply to: ↑ 12 Changed 5 years ago by ncohen

Yo !

Ok. Will see that later. I postponed to #16535 if you agree.

I will have to rebase what is currently above this patch, then.

Well.... does not matter...

But why not having orthogonal_array implements the three lines that are right now in find_recursive_construction?

Oh, you mean only the part that actually creates the design ? Yeah, why not !...

I will add a commit for that in a second.

Nathann

comment:14 Changed 5 years ago by git

  • Commit changed from a67c04f13bd0aa2b46e6998d2b996437f342470c to 41c50d5a256d9e746d8acfb33a4ff7c58e05789b

Branch pushed to git repo; I updated commit sha1. New commits:

41c50d5trac #16500: Simplified find_recursive_construction

comment:15 follow-up: Changed 5 years ago by vdelecroix

Hi,

small commit at u/vdelecroix/16500

Be careful that a truncated OA is not an incomplete OA. In truncated OA you removed points in columns whereas in incomplete OA you have less blocks than an OA (but columns are not changed)... it is very confusing to read your doc. And moreover you use block or column indifferently but it would be better to have a unique name for that.

In the doc of the construction 3.4 there is

- If there exists an `OA(k,m+r+1)` the column of size `s` is truncated in
  order to intersect `B_0`.

- If there exists an `OA(k,m+r+1)`, the last column must not intersect `B_0`

which is contradictory!

The rest is fine except that there is no need to use linear programming to build an oval, see #16552.

Vincent

comment:16 Changed 5 years ago by vdelecroix

  • Status changed from needs_review to needs_work

comment:17 in reply to: ↑ 15 Changed 5 years ago by ncohen

Yo !

small commit at u/vdelecroix/16500

Looks good !

Be careful that a truncated OA is not an incomplete OA.

Arg yes yes, I always mix the two words ^^;

And moreover you use block or column indifferently but it would be better to have a unique name for that.

Do you mean "column or group" ? There are n^2 blocks in an OA(k,n) but k columns.

In the doc of the construction 3.4 there is

- If there exists an `OA(k,m+r+1)` the column of size `s` is truncated in
  order to intersect `B_0`.

- If there exists an `OA(k,m+r+1)`, the last column must not intersect `B_0`

which is contradictory!

I don't se how O_o

The rest is fine except that there is no need to use linear programming to build an oval, see #16552.

Oh ? Cool. Free ovals ! :-D

Nathann

comment:18 Changed 5 years ago by git

  • Commit changed from 41c50d5a256d9e746d8acfb33a4ff7c58e05789b to e1992ce4c0a145ce8fd61fae0abe0809cd6ff173

Branch pushed to git repo; I updated commit sha1. New commits:

e1992cetrac #16500: doc + speedup

comment:19 follow-up: Changed 5 years ago by ncohen

What exactly needs work ?

Nathann

comment:20 in reply to: ↑ 19 Changed 5 years ago by vdelecroix

Replying to ncohen:

What exactly needs work ?

the doc of construction 3.4

comment:21 Changed 5 years ago by ncohen

Then please answer my question above : what is wrong in those sentences ?

Nathann

comment:22 Changed 5 years ago by ncohen

Oh. Right.

comment:23 Changed 5 years ago by git

  • Commit changed from e1992ce4c0a145ce8fd61fae0abe0809cd6ff173 to 697dd0ca8284485897b051015af74b385c345fb4

Branch pushed to git repo; I updated commit sha1. New commits:

697dd0ctrac #16500: Typoes in the doc

comment:24 Changed 5 years ago by ncohen

  • Status changed from needs_work to needs_review

comment:25 follow-up: Changed 5 years ago by vdelecroix

  • Status changed from needs_review to positive_review

This one was much easier once the Wilson construction is understood!

Do you already did the even more general construction from Brouwer-Rees 1982 (they consider generalization of truncated OA where the extra columns are partitioned in possibly more than two parts)?

Vincent

comment:26 Changed 5 years ago by vdelecroix

  • Reviewers set to Vincent Delecroix

comment:27 in reply to: ↑ 25 ; follow-up: Changed 5 years ago by ncohen

Yo !

This one was much easier once the Wilson construction is understood!

Yep yep. That's what I will remember of design theory. Deadly scary stuff that becomes totally straightforward once you pay attention to it.

Still, a lot of stuff remains deadly scary in the field :-P

Do you already did the even more general construction from Brouwer-Rees 1982 (they consider generalization of truncated OA where the extra columns are partitioned in possibly more than two parts)?

Now yet, but I will have to. What scares me is not the implementation of the construction, but how to properly write the input part of the function T_T

Nathann

comment:28 in reply to: ↑ 27 Changed 5 years ago by ncohen

This one was much easier once the Wilson construction is understood!

Some smarter comment: I believe that it is thanks to work like the one we do that we can get to understand such things. That's how it happened to me with LP : I had to implement very basic things 1000 times for Sage, and in the end I find myself understanding the basics properly, which would have NEVER happened if I had just had a book in front of me. Or even if it was in Sage's code.

When you implement Sage stuff you are forced to spend time on things you would quickly look at otherwise.

Nathann

comment:29 Changed 5 years ago by vbraun

  • Branch changed from u/ncohen/16500 to 697dd0ca8284485897b051015af74b385c345fb4
  • Resolution set to fixed
  • Status changed from positive_review to closed
Note: See TracTickets for help on using tickets.