Opened 7 years ago

Closed 7 years ago

#16476 closed enhancement (fixed)

New difference family (25,4,1) and cleanup in bibd.py

Reported by: vdelecroix Owned by:
Priority: major Milestone: sage-6.3
Component: combinatorial designs Keywords:
Cc: ncohen Merged in:
Authors: Vincent Delecroix Reviewers: Nathann Cohen
Report Upstream: N/A Work issues:
Branch: 032ee82 (Commits) Commit: 032ee826d06ce0241917277938defcc968c38c71
Dependencies: #16461 Stopgaps:

Description (last modified by vdelecroix)

In the construction of Stinson book the BIBD(25,4,1) comes from a difference family so we can just add it to the database. Moreover the function PBD_4_5_8_9_12 previously failed for v=4,5,8,9,12 where the trivial answer [range(v)] just fits.

Change History (15)

comment:1 Changed 7 years ago by vdelecroix

  • Description modified (diff)
  • Status changed from new to needs_review

All right, this is rather trivial, but it cleans a bit the bibd stuff.

comment:2 Changed 7 years ago by vdelecroix

  • Branch set to u/vdelecroix/16461
  • Commit set to 8b1e6cefc5d2bae89d9a23c75a78e558ef6d3826

Last 10 new commits:

f0474bbtrac #16464: be more careful with errors
21cb1a8trac #16464: handle correctly arguments for cyclotomic_cosets
b07ad01trac #16464: Second review
136e870trac #16464: tiny improvements for is_a_splitting
965f550trac #16464: replace bool(S1&S2) by S1.isdisjoint(S2)
9b199c7trac #16461: merge #16464
2d12cc0trac #16461: adapt the implementation with #16464
d3d6a31trac #16461: reset finite_field_base.pyx to its previous state
2638697trac #16461: always check the difference family
8b1e6cetrac #16461: get rid of _nonzero_and_have_distinct_images

comment:3 Changed 7 years ago by vdelecroix

  • Branch changed from u/vdelecroix/16461 to u/vdelecroix/16476
  • Commit changed from 8b1e6cefc5d2bae89d9a23c75a78e558ef6d3826 to ee3b03584f8a60e892734193793dc1c20b6007c0

Last 10 new commits:

90f828ftrac #16391: use OrthogonalArrayBlockGraph instead of OrthogonalArrayGraph
6e3c685trac #16391: reviewer's comments
52c2de8trac #16391: Removing the holes
d0885f7trac #16391: bugfix
c1de597trac #16391: doc clean + remove some list construction
41a9a24trac #16391: Typo
42239cctrac #16391: Undoing stuff
24ac3a8trac #16391: Broken doc
70c9805trac #16391: Merged with #16460
ee3b035trac #16461: Merged with #16391

comment:4 Changed 7 years ago by git

  • Commit changed from ee3b03584f8a60e892734193793dc1c20b6007c0 to 868e0b0a40d0706e599cd60c7fedb013accbfd66

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

868e0b0trac #16476: new (25,4,1) DF and clean bibd.py

comment:5 follow-up: Changed 7 years ago by ncohen

Good to go ! I wondered about that though... Do we care ? Should we check that the set of block sizes contains integer > 1 ?

sage: from sage.combinat.designs.bibd import _check_pbd
sage: _check_pbd([[1],[]],1,[1,0])
...
RuntimeError: This is not a nice honest PBD from the good old days!

Nathann

comment:6 in reply to: ↑ 5 ; follow-up: Changed 7 years ago by vdelecroix

Replying to ncohen:

Good to go ! I wondered about that though... Do we care ? Should we check that the set of block sizes contains integer > 1 ?

sage: from sage.combinat.designs.bibd import _check_pbd
sage: _check_pbd([[1],[]],1,[1,0])
...
RuntimeError: This is not a nice honest PBD from the good old days!

Actually, it would make more sense to have is_pairwise_balanced_design in designs_pyx.pyx... and testing that blocks are non-empty certainly needed! What do you want do be added to that ticket?

comment:7 in reply to: ↑ 6 Changed 7 years ago by ncohen

Actually, it would make more sense to have is_pairwise_balanced_design in designs_pyx.pyx... and testing that blocks are non-empty certainly needed! What do you want do be added to that ticket?

I will add a commit in a second to check this, before we move it to another file.

In the meantime could you check the doc of #16461 ? It does not build on my computer and Volker will set it back to needs_work.

Nathann

comment:8 Changed 7 years ago by ncohen

  • Reviewers set to Nathann Cohen

New commit at public/16476.

Nathann

comment:9 follow-up: Changed 7 years ago by vdelecroix

Block of size 1 are not allowed? The Handbook says "Let K be a subset of positive integers"...

comment:10 in reply to: ↑ 9 ; follow-up: Changed 7 years ago by ncohen

Block of size 1 are not allowed? The Handbook says "Let K be a subset of positive integers"...

What do we do with the PBD with v=1 or v=0 and many sets of size 0,1 ?

Nathann

comment:11 in reply to: ↑ 10 ; follow-up: Changed 7 years ago by vdelecroix

Replying to ncohen:

Block of size 1 are not allowed? The Handbook says "Let K be a subset of positive integers"...

What do we do with the PBD with v=1 or v=0 and many sets of size 0,1 ?

Yup. You are right. Makes more sense to exclude them.

Are we happy with this?

comment:12 in reply to: ↑ 11 Changed 7 years ago by ncohen

Are we happy with this?

Are you willing to add my commit ?

Nathann

comment:13 Changed 7 years ago by vdelecroix

  • Branch changed from u/vdelecroix/16476 to public/16476
  • Commit changed from 868e0b0a40d0706e599cd60c7fedb013accbfd66 to 032ee826d06ce0241917277938defcc968c38c71

Of course, we take it!


New commits:

032ee82trac #16476: Additional check

comment:14 Changed 7 years ago by ncohen

  • Status changed from needs_review to positive_review

comment:15 Changed 7 years ago by vbraun

  • Branch changed from public/16476 to 032ee826d06ce0241917277938defcc968c38c71
  • Resolution set to fixed
  • Status changed from positive_review to closed
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