Opened 9 years ago

Closed 9 years ago

Last modified 9 years ago

#8745 closed enhancement (fixed)

Steiner Triple Systems

Reported by: ncohen Owned by: sage-combinat
Priority: major Milestone: sage-4.4.1
Component: combinatorics Keywords:
Cc: wdj Merged in: sage-4.4.1.alpha2
Authors: Nathann Cohen Reviewers: David Joyner
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Description

This patch adds a function to block_design returning a Steiner Triple System on any number of vertices n congruent to 1 or 3 modulo 6. There is none otherwise :-)

The function is pretty short, a satisfiable decomposition being explicitely given in the reference : ​http://www.utu.fi/~honkala/designs.ps

Nathann

Attachments (1)

trac_8745.patch​ (4.6 KB) - added by ncohen 9 years ago.

Download all attachments as: .zip

Change History (7)

Changed 9 years ago by ncohen

comment:1 Changed 9 years ago by ncohen

  • Status changed from new to needs_review

comment:2 Changed 9 years ago by wdj

  • Status changed from needs_review to positive_review

Applies fine to 4.4.a1, passes sage -testall on a 10.6.2 mac (except for the r.py failure, which is unrelated), and looks good to me in terms of examples and references.

Thanks Nathann!

comment:3 Changed 9 years ago by ncohen

Whaouuuuuuu !!! Such a quick review :-)

Thank you very much too !! :-)

Nathann

comment:4 Changed 9 years ago by was

  • Merged in set to 4.4.1.alpha2
  • Resolution set to fixed
  • Status changed from positive_review to closed

comment:5 Changed 9 years ago by mvngu

  • Authors set to Nathann Cohen
  • Reviewers set to David Joyner

comment:6 Changed 9 years ago by mvngu

  • Merged in changed from 4.4.1.alpha2 to sage-4.4.1.alpha2
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