Opened 3 years ago

Closed 3 years ago

#19861 closed enhancement (fixed)

Janko-Kharaghani strongly regular graphs of orders 936 and 1800

Reported by: ncohen Owned by:
Priority: major Milestone: sage-7.0
Component: graph theory Keywords:
Cc: dimpase Merged in:
Authors: Nathann Cohen Reviewers: Dima Pasechnik
Report Upstream: N/A Work issues:
Branch: 58a483c (Commits) Commit: 58a483c98f044e88dc6d1a419632df9862f79f2d
Dependencies: Stopgaps:

Description

Here is one of the few missing SRG with v<1300.

Nathann

Change History (16)

comment:1 Changed 3 years ago by ncohen

  • Branch set to u/ncohen/19861
  • Commit set to caadbe3bb007230b2269f13b22e9233c129a9286
  • Status changed from new to needs_review
  • Summary changed from JankoKharaghani strongly regular graphs of orders 936 and 1800 to Janko-Kharaghani strongly regular graphs of orders 936 and 1800

New commits:

​caadbe3trac #19861: Janko-Kharaghani strongly regular graphs of orders 936 and 1800

comment:2 Changed 3 years ago by dimpase 

+        sage: g = JankoKharaghani(1800)              # not tested (30s)
+        sage: g.is_strongly_regular(parameters=True) # not tested (30s)
+        (936, 375, 150, 150)

huh?

comment:3 Changed 3 years ago by ncohen

Drop me a line when you will be able to communicate in full english sentences.

comment:4 Changed 3 years ago by ncohen

Oh. Right. 1800.

comment:5 Changed 3 years ago by git

  • Commit changed from caadbe3bb007230b2269f13b22e9233c129a9286 to e34888ccd82ab8fa361b712cbff0883c4eb884c3

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

​e34888ctrac #19861: Janko-Kharaghani strongly regular graphs of orders 936 and 1800

comment:6 Changed 3 years ago by dimpase

As e.g. MathonStronglyRegularGraph is in graphs/generators/smallgraphs.py, this one should also be there, don't you think so? We don't have any "named graphs" in graphs/strongly_regular_db.pyx, and let's keep it this way, OK?

comment:7 follow-up: Changed 3 years ago by ncohen

Hmmmm.... Okay... I admit that I don't like much to have in graphs.<tab> a constructor that nobody will never call, but well... Okay :-/

comment:8 follow-up: Changed 3 years ago by dimpase

We perhaps should also think where H should go, in a special row of cages in Hadamard Zoo, maybe...

comment:9 Changed 3 years ago by git

  • Commit changed from e34888ccd82ab8fa361b712cbff0883c4eb884c3 to 58a483c98f044e88dc6d1a419632df9862f79f2d

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

​58a483ctrac #19861: Janko-Kharaghani strongly regular graphs of orders 936 and 1800

comment:10 in reply to: ↑ 8 Changed 3 years ago by ncohen

We perhaps should also think where H should go, in a special row of cages in Hadamard Zoo, maybe...

Hmmm?? It looks far too specific to me.

comment:11 in reply to: ↑ 7 Changed 3 years ago by ncohen

Hmmmm.... Okay... I admit that I don't like much to have in graphs.<tab> a constructor that nobody will never call, but well... Okay :-/

Done.

comment:12 Changed 3 years ago by dimpase

Would you mind if I add the v=324 case from them to this ticket?

comment:13 Changed 3 years ago by dimpase

added in public/JKandJKT

comment:14 follow-up: Changed 3 years ago by dimpase

  • Reviewers set to Dima Pasechnik
  • Status changed from needs_review to positive_review

OK, I guess it's faster to do another ticket. This one is good to go.

comment:15 in reply to: ↑ 14 Changed 3 years ago by ncohen

OK, I guess it's faster to do another ticket. This one is good to go.

Indeed.

Thanks!

Nathann

comment:16 Changed 3 years ago by vbraun

  • Branch changed from u/ncohen/19861 to 58a483c98f044e88dc6d1a419632df9862f79f2d
  • Resolution set to fixed
  • Status changed from positive_review to closed
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