Opened 3 years ago

Closed 3 years ago

#19180 closed enhancement (fixed)

A (220,84,38,28)-strongly regular graph

Reported by: ncohen Owned by:
Priority: major Milestone: sage-6.9
Component: graph theory Keywords:
Cc: dimpase Merged in:
Authors: Nathann Cohen Reviewers: Dima Pasechnik
Report Upstream: N/A Work issues:
Branch: 6ce1899 (Commits) Commit: 6ce189941a6a7d63f0fd100ef3cc8c680483c1f0
Dependencies: #19133 Stopgaps:

Description

A new graph to be added to our collection.

Nathann

Change History (10)

comment:1 Changed 3 years ago by ncohen

  • Branch set to public/19180
  • Commit set to d9be4b94f02e6cb0ce6335025916098c2c0e770f
  • Status changed from new to needs_review

New commits:

302e6bctrac #19133: Three Witt-based strongly regular graphs
6c0c890trac #19133: Merged with 6.9.beta5
3bc31a1trac #19133: Broken doctests
d9be4b9trac #19180: A (220,84,38,28)-strongly regular graph

comment:2 Changed 3 years ago by git

  • Commit changed from d9be4b94f02e6cb0ce6335025916098c2c0e770f to 7cbfa8b1425fccb6ca404a6f72f253b5ccf99eeb

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

7cbfa8btrac #19180: A (220,84,38,28)-strongly regular graph

comment:3 follow-up: Changed 3 years ago by jsrn

You mentioned (on https://groups.google.com/forum/#!topic/sage-support/dPG73HQZK-Y) that the function takes 40s. I don't have time right now to check out the ticket and compile and test, but I get

sage: %timeit L = [ w for w in codes.ExtendedQuadraticResidueCode(47,GF(2)) if w.hamming_weight() == 12 ]
1 loops, best of 3: 16.4 s per loop

By the way, glancing through your code, you should probably use hamming_weight and not sum to determine the hamming weight. Sum could (should?) behave as over GF(2) in something like this code.

comment:4 follow-up: Changed 3 years ago by jsrn

Pretty awesome way you compacted and cached the results, btw :-)

comment:5 in reply to: ↑ 3 Changed 3 years ago by ncohen

By the way, glancing through your code, you should probably use hamming_weight

Right, it is faster indeed. It now takes ~12s. hamming_weight does the job at a much lower level.

and not sum to determine the hamming weight. Sum could (should?) behave as over GF(2) in something like this code.

I apply it to ints, not to GF(2) elements.

Thanks,

Nathann

comment:6 Changed 3 years ago by git

  • Commit changed from 7cbfa8b1425fccb6ca404a6f72f253b5ccf99eeb to 6ce189941a6a7d63f0fd100ef3cc8c680483c1f0

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

6ce1899trac #19180: Speedup

comment:7 in reply to: ↑ 4 Changed 3 years ago by ncohen

Pretty awesome way you compacted and cached the results, btw :-)

The first version was in base 10, but I know Dima does not like to see long lists like that. So I tried to make it a bit smaller :-P

Nathann

comment:8 Changed 3 years ago by dimpase

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

looks good to me.

comment:9 Changed 3 years ago by ncohen

Thaaaaaaaaaaaaaanks !!!

comment:10 Changed 3 years ago by vbraun

  • Branch changed from public/19180 to 6ce189941a6a7d63f0fd100ef3cc8c680483c1f0
  • Resolution set to fixed
  • Status changed from positive_review to closed
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