Opened 3 years ago
Closed 3 years ago
#19353 closed enhancement (fixed)
A (729, 448, 277, 272)strongly regular graph
Reported by:  ncohen  Owned by:  

Priority:  major  Milestone:  sage6.9 
Component:  graph theory  Keywords:  
Cc:  dimpase  Merged in:  
Authors:  Nathann Cohen  Reviewers:  Dima Pasechnik 
Report Upstream:  N/A  Work issues:  
Branch:  c280e4d (Commits)  Commit:  c280e4d269104f9d5183eed42cff761b8aab623b 
Dependencies:  #19335  Stopgaps: 
Description
As the title says. The last of the SRG advertised in the database as coming "from a twoweight code".
Change History (15)
comment:1 Changed 3 years ago by
 Branch set to u/ncohen/19353
 Commit set to d5f10f7e308bf0fdbe9cfd2b7cc39eab6ace8eb4
 Status changed from new to needs_review
comment:2 followup: ↓ 3 Changed 3 years ago by
 Status changed from needs_review to positive_review
OK, the last, I hope. How about (729 336 153 156 ), though? Sage says
...Penttila & Royle: projective 9ary [42,3] code with weights 36, 39
I'm about to start complaining that all these 2weight codes should go to where they belong to, and we just get them from sage.codes.whatever
.
comment:3 in reply to: ↑ 2 ; followup: ↓ 4 Changed 3 years ago by
OK, the last, I hope. How about (729 336 153 156 ), though? Sage says
...Penttila & Royle: projective 9ary [42,3] code with weights 36, 39
Isn't that #19311?
I'm about to start complaining that all these 2weight codes should go to where they belong to, and we just get them from
sage.codes.whatever
.
And you would be right to. It takes a lifetime to compile this cython module, and most of it has no reason to be cython code. Would you feel like writing this twocode module in sage.coding? It is clear that it belongs there, but given that I still do not totally understand all the meaning of all parameters in a "projective 9ary [42,3] code with weights 36, 39", I do not feel much at ease implementing and documenting all that...
Nathann
comment:4 in reply to: ↑ 3 ; followup: ↓ 5 Changed 3 years ago by
Replying to ncohen:
OK, the last, I hope. How about (729 336 153 156 ), though? Sage says
...Penttila & Royle: projective 9ary [42,3] code with weights 36, 39
Isn't that #19311?
isn't #19311 about something different  twointersection code(s)?
I'm about to start complaining that all these 2weight codes should go to where they belong to, and we just get them from
sage.codes.whatever
.And you would be right to. It takes a lifetime to compile this cython module, and most of it has no reason to be cython code. Would you feel like writing this twocode module in sage.coding? It is clear that it belongs there, but given that I still do not totally understand all the meaning of all parameters in a "projective 9ary [42,3] code with weights 36, 39", I do not feel much at ease implementing and documenting all that...
I recall having a long tread, either in email, or in some google groups, or on trac, where I explained (to myself mostly) the stuff on projective codes. I can't seem to locate it. Did I just dream about it? Or perhaps you know where to find this?
comment:5 in reply to: ↑ 4 ; followup: ↓ 6 Changed 3 years ago by
isn't #19311 about something different  twointersection code(s)?
It's up to you. I read somewhere that twointersection codes were equivalent to twoweight codes.
I do not mind much myself, as long as the graph is generated.
I recall having a long tread, either in email, or in some google groups, or on trac, where I explained (to myself mostly) the stuff on projective codes. I can't seem to locate it. Did I just dream about it? Or perhaps you know where to find this?
HMmmmmmm... It does not ring a bell.. Can't tell, sorry.
Nathann
comment:6 in reply to: ↑ 5 ; followup: ↓ 7 Changed 3 years ago by
Replying to ncohen:
isn't #19311 about something different  twointersection code(s)?
It's up to you. I read somewhere that twointersection codes were equivalent to twoweight codes.
I do not mind much myself, as long as the graph is generated.
OK, so if we knew this transformation, then no need for a new way to build graphs would be needed, right?
I recall having a long tread, either in email, or in some google groups, or on trac, where I explained (to myself mostly) the stuff on projective codes. I can't seem to locate it. Did I just dream about it? Or perhaps you know where to find this?
HMmmmmmm... It does not ring a bell.. Can't tell, sorry.
ah, it's on #18960. Good. (I checked my mailboxes, google groups, but not trac ;))
comment:7 in reply to: ↑ 6 Changed 3 years ago by
OK, so if we knew this transformation, then no need for a new way to build graphs would be needed, right?
And the library would be poorer as a result. Anyway: I think that they are equivalent, but I worry that building one from the other may take a *long* time (which of course does not matter in the theory).
Nathann
comment:8 followup: ↓ 9 Changed 3 years ago by
This and #19350 need reviewer's name.
And this trac system needs automatic rejection for positive reviews without reviewer names.
comment:9 in reply to: ↑ 8 Changed 3 years ago by
And this trac system needs automatic rejection for positive reviews without reviewer names.
I don't necessarily agree. In my experience, the easiest would be for Dima to finally learn that he has to fill his name where it belongs. And we are talking of powerful magic here.
Natahnn
comment:10 followup: ↓ 11 Changed 3 years ago by
 Reviewers set to Dima Pasechnik
I live my life with an undiagnosed learning disability, you know...
comment:11 in reply to: ↑ 10 Changed 3 years ago by
I live my life with an undiagnosed learning disability, you know...
It was quite daring of you to pick a researcher's career :P
Nathann
comment:13 Changed 3 years ago by
 Commit changed from d5f10f7e308bf0fdbe9cfd2b7cc39eab6ace8eb4 to c280e4d269104f9d5183eed42cff761b8aab623b
Branch pushed to git repo; I updated commit sha1. New commits:
c280e4d  trac #19353: Merged with 6.10.beta0

comment:14 Changed 3 years ago by
 Status changed from needs_work to positive_review
comment:15 Changed 3 years ago by
 Branch changed from u/ncohen/19353 to c280e4d269104f9d5183eed42cff761b8aab623b
 Resolution set to fixed
 Status changed from positive_review to closed
New commits:
trac #19353: A (729, 448, 277, 272)strongly regular graph