Opened 9 years ago
Closed 9 years ago
#16476 closed enhancement (fixed)
New difference family (25,4,1) and cleanup in bibd.py
Reported by: | vdelecroix | Owned by: | |
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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, GitHub, GitLab) | Commit: | 032ee826d06ce0241917277938defcc968c38c71 |
Dependencies: | #16461 | Stopgaps: |
Description (last modified by )
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 9 years ago by
Description: | modified (diff) |
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Status: | new → needs_review |
comment:2 Changed 9 years ago by
Branch: | → u/vdelecroix/16461 |
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Commit: | → 8b1e6cefc5d2bae89d9a23c75a78e558ef6d3826 |
Last 10 new commits:
f0474bb | trac #16464: be more careful with errors
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21cb1a8 | trac #16464: handle correctly arguments for cyclotomic_cosets
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b07ad01 | trac #16464: Second review
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136e870 | trac #16464: tiny improvements for is_a_splitting
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965f550 | trac #16464: replace bool(S1&S2) by S1.isdisjoint(S2)
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9b199c7 | trac #16461: merge #16464
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2d12cc0 | trac #16461: adapt the implementation with #16464
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d3d6a31 | trac #16461: reset finite_field_base.pyx to its previous state
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2638697 | trac #16461: always check the difference family
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8b1e6ce | trac #16461: get rid of _nonzero_and_have_distinct_images
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comment:3 Changed 9 years ago by
Branch: | u/vdelecroix/16461 → u/vdelecroix/16476 |
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Commit: | 8b1e6cefc5d2bae89d9a23c75a78e558ef6d3826 → ee3b03584f8a60e892734193793dc1c20b6007c0 |
Last 10 new commits:
90f828f | trac #16391: use OrthogonalArrayBlockGraph instead of OrthogonalArrayGraph
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6e3c685 | trac #16391: reviewer's comments
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52c2de8 | trac #16391: Removing the holes
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d0885f7 | trac #16391: bugfix
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c1de597 | trac #16391: doc clean + remove some list construction
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41a9a24 | trac #16391: Typo
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42239cc | trac #16391: Undoing stuff
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24ac3a8 | trac #16391: Broken doc
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70c9805 | trac #16391: Merged with #16460
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ee3b035 | trac #16461: Merged with #16391
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comment:4 Changed 9 years ago by
Commit: | ee3b03584f8a60e892734193793dc1c20b6007c0 → 868e0b0a40d0706e599cd60c7fedb013accbfd66 |
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Branch pushed to git repo; I updated commit sha1. New commits:
868e0b0 | trac #16476: new (25,4,1) DF and clean bibd.py
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comment:5 follow-up: 6 Changed 9 years ago by
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 follow-up: 7 Changed 9 years ago by
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 Changed 9 years ago by
Actually, it would make more sense to have
is_pairwise_balanced_design
indesigns_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:9 follow-up: 10 Changed 9 years ago by
Block of size 1 are not allowed? The Handbook says "Let K be a subset of positive integers"...
comment:10 follow-up: 11 Changed 9 years ago by
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 follow-up: 12 Changed 9 years ago by
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 Changed 9 years ago by
Are we happy with this?
Are you willing to add my commit ?
Nathann
comment:13 Changed 9 years ago by
Branch: | u/vdelecroix/16476 → public/16476 |
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Commit: | 868e0b0a40d0706e599cd60c7fedb013accbfd66 → 032ee826d06ce0241917277938defcc968c38c71 |
comment:14 Changed 9 years ago by
Status: | needs_review → positive_review |
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comment:15 Changed 9 years ago by
Branch: | public/16476 → 032ee826d06ce0241917277938defcc968c38c71 |
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Resolution: | → fixed |
Status: | positive_review → closed |
All right, this is rather trivial, but it cleans a bit the bibd stuff.