Opened 2 years ago
Closed 2 years ago
#30037 closed enhancement (fixed)
Added a construction for BIBDs from symmetric BIBDs
Reported by: | gh-Ivo-Maffei | Owned by: | |
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Priority: | major | Milestone: | sage-9.2 |
Component: | combinatorial designs | Keywords: | bibd |
Cc: | Dima Pasechnik | Merged in: | |
Authors: | Ivo Maffei | Reviewers: | Dima Pasechnik |
Report Upstream: | N/A | Work issues: | |
Branch: | aac95be (Commits, GitHub, GitLab) | Commit: | aac95beaa3de54a990b06be27b1ca7a529884634 |
Dependencies: | #29959 | Stopgaps: |
Description
Given a symmetric (v, k, lambd)
-BIBD one can build a (v-k, k-lambd, lambd)
-BIBD by removing a block from the former.
For more on BIBDs see https://en.wikipedia.org/wiki/Block_design#Definition_of_a_BIBD_(or_2-design)
Change History (5)
comment:1 Changed 2 years ago by
Commit: | e608ef8346e58e62b0b9eb76358f110511ec5451 → aac95beaa3de54a990b06be27b1ca7a529884634 |
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comment:2 Changed 2 years ago by
Cc: | Dima Pasechnik added |
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Status: | new → needs_review |
comment:3 Changed 2 years ago by
to test this recursive builder, it would be nice to have a (maybe internal) function to build all the 2-designs known to Sage with at most v points and with lambda in a given range.
comment:4 Changed 2 years ago by
Reviewers: | → Dima Pasechnik |
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Status: | needs_review → positive_review |
Please do what I propose in comment:3 on another ticket.
As an example of such a test, cf. _check_database()
in sage.graphs.strongly_regular_db
.
comment:5 Changed 2 years ago by
Branch: | u/gh-Ivo-Maffei/recursive_bibd → aac95beaa3de54a990b06be27b1ca7a529884634 |
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Resolution: | → fixed |
Status: | positive_review → closed |
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Branch pushed to git repo; I updated commit sha1. New commits:
changed docstring
Merge branch 'bibd' into recursive_bibd
fixed bug; added tests