Opened 3 years ago
Closed 3 years ago
#18934 closed enhancement (fixed)
New (v,6,1)BIBD with v<=201
Reported by:  ncohen  Owned by:  

Priority:  major  Milestone:  sage6.8 
Component:  combinatorial designs  Keywords:  
Cc:  dimpase, vdelecroix  Merged in:  
Authors:  Nathann Cohen  Reviewers:  Dima Pasechnik 
Report Upstream:  N/A  Work issues:  
Branch:  6ed1abf (Commits)  Commit:  6ed1abf670cc7212d0f287458bd3af9588adf21c 
Dependencies:  Stopgaps: 
Description (last modified by )
This branch adds new BIBD to our database. Some are stolen from the La Jolla Covering Repository (https://www.ccrwest.org/cover.html), and other from the handbook of combinatorial designs.
They will be useful to generate strongly regular graphs from Brouwer's database #18948 (http://www.win.tue.nl/~aeb/)
Nathann
Change History (32)
comment:1 Changed 3 years ago by
 Branch set to u/ncohen/18934
 Commit set to a0cac6672fd589aaee7f10742dea975a167ecffe
 Status changed from new to needs_review
comment:2 Changed 3 years ago by
 Description modified (diff)
comment:3 Changed 3 years ago by
 Commit changed from a0cac6672fd589aaee7f10742dea975a167ecffe to e46b0583561c5c69722a306f1cd68675715556ef
Branch pushed to git repo; I updated commit sha1. New commits:
e46b058  trac #18934: New (v,6,1)BIBD with v=201

comment:4 Changed 3 years ago by
 Summary changed from new BIBD: (91,7,1), (66,6,1), (76,6,1), (96,6,1) to New (v,6,1)BIBD with v<=201
comment:5 Changed 3 years ago by
 Commit changed from e46b0583561c5c69722a306f1cd68675715556ef to a04a2fb5139cd4f1f601935f07d63e09a03fcf95
Branch pushed to git repo; I updated commit sha1. New commits:
a04a2fb  trac #18934: Broken doctests

comment:6 Changed 3 years ago by
 Commit changed from a04a2fb5139cd4f1f601935f07d63e09a03fcf95 to 11e9f1f3b3b9a64326bfe71dc1bf96c91fe52de6
Branch pushed to git repo; I updated commit sha1. New commits:
11e9f1f  trac #18934: Last one > (126,6,1)BIBD

comment:7 followup: ↓ 9 Changed 3 years ago by
Was this interface https://www.ccrwest.org/cover/sage.html, to the database you get these designs, removed?
comment:8 Changed 3 years ago by
comment:9 in reply to: ↑ 7 Changed 3 years ago by
Was this interface https://www.ccrwest.org/cover/sage.html, to the database you get these designs, removed?
sage: designs.best_known_covering_design_from_LJCR?
Nathann
comment:10 followup: ↓ 11 Changed 3 years ago by
Most of these designs do not come from there, though. The references are in the doc.
comment:11 in reply to: ↑ 10 ; followup: ↓ 12 Changed 3 years ago by
Replying to ncohen:
Most of these designs do not come from there, though. The references are in the doc.
well, I read the ticket description, and it tells a different story :)
Still, why just do
sage: designs.best_known_covering_design_from_LJCR(66,6,2) (66,6,2)covering design of size 143 Lower bound: 143 Created by: Colin Barker Submitted on: 20081114 09:35:27 sage: designs.best_known_covering_design_from_LJCR(76,6,2) (76,6,2)covering design of size 190 Lower bound: 190 Created by: Colin Barker Submitted on: 20081114 09:37:55
for these values for parameters? (And contributing the other implementations upstream?)
comment:12 in reply to: ↑ 11 Changed 3 years ago by
 Description modified (diff)
Yo,
well, I read the ticket description, and it tells a different story :)
Oh, true.
for these values for parameters? (And contributing the other implementations upstream?)
Because it would means that anything that uses those constructions requires internet. And that database does not contain anything above v=100.
Nathann
comment:13 Changed 3 years ago by
And this data is "not exactly" the one found upstream either. What is advertised there as a covering has a nice automorphism group, and is actually a difference family. So I added it as such in Sage.
comment:14 followup: ↓ 16 Changed 3 years ago by
Anyhow, the references to the database better be in the form
designs.best_known_covering_design_from_LJCR(66,6,2) designs.best_known_covering_design_from_LJCR(76,6,2)
Otherwise, looks good to go.
comment:15 followup: ↓ 17 Changed 3 years ago by
and, by the way:
sage: designs.best_known_covering_design_from_LJCR(91,7,2) (91,7,2)covering design of size 195 Lower bound: 195 Created by: Jan de Heer and Steve Muir Method: Cyclic Steiner System Submitted on: 20081207 02:34:05
is this the same (91,7,1)example as on this ticket?
comment:16 in reply to: ↑ 14 Changed 3 years ago by
Anyhow, the references to the database better be in the form
designs.best_known_covering_design_from_LJCR(66,6,2) designs.best_known_covering_design_from_LJCR(76,6,2)
I do not understand what you mean.
comment:17 in reply to: ↑ 15 Changed 3 years ago by
is this the same (91,7,1)example as on this ticket?
Yes it is. I fixed the reference.
comment:18 Changed 3 years ago by
 Commit changed from 11e9f1f3b3b9a64326bfe71dc1bf96c91fe52de6 to 6ed1abf670cc7212d0f287458bd3af9588adf21c
comment:19 Changed 3 years ago by
 Reviewers set to Dima Pasechnik
 Status changed from needs_review to needs_work
merges cleanly in Sage 6.8.
What I meant by comment 14, is that it takes some research to dig up the way to actually get these from the database (e.g. instead of ...,1)
it needs ...,2)
), and it would be good to include the corresponding Sage commands in the doc. Otherwise good to go.
comment:20 Changed 3 years ago by
I still do not understand what you mean.
comment:21 Changed 3 years ago by
Can you say what modification to this branch you request?
comment:22 Changed 3 years ago by
OK, OK, you will get my branch in a moment...
comment:23 Changed 3 years ago by
 Branch changed from u/ncohen/18934 to public/18934
 Commit changed from 6ed1abf670cc7212d0f287458bd3af9588adf21c to 819bfa02346262814a0ff5ef3a9831eda7579739
 Description modified (diff)
 Status changed from needs_work to needs_review
comment:24 Changed 3 years ago by
O_o
Bu *WHY* would you want to make sure that they are the same as upstream? What if upstream changes them? O_o
comment:25 followup: ↓ 26 Changed 3 years ago by
By the way: you do not need to import BalancedIncompleteBlockDesign nor the individual functions because they are imported in the previous doctest. Also, .sort()
returns 'None' and that's why b==b0
always returns 'True'.
Finally, there is an equality test defined over incidence which you should use (and it says that they are not equal, though they will be isomorphic as I relabeled them).
Nathann
comment:26 in reply to: ↑ 25 ; followup: ↓ 27 Changed 3 years ago by
Replying to ncohen:
By the way: you do not need to import BalancedIncompleteBlockDesign nor the individual functions because they are imported in the previous doctest.
ah, OK, I never knew whether EXAMPLES and TESTS are done in the same sweep...
Also,
.sort()
returns 'None' and that's whyb==b0
always returns 'True'.
oops. Anyhow, I merely wanted the actual calls to that designs...._LJCR
be shown in the docs somewhere.
We can try isomorphism testing, but I bet it is as slow as a turtle...
comment:27 in reply to: ↑ 26 ; followup: ↓ 28 Changed 3 years ago by
oops. Anyhow, I merely wanted the actual calls to that
designs...._LJCR
be shown in the docs somewhere.
I still can't see the point of that. All we care about (all that the function promises) is that it returns "some" bibd. If that works, then it rolls.
We can try isomorphism testing, but I bet it is as slow as a turtle...
If it is, install 'bliss'. Should go way faster.
Nathann
comment:28 in reply to: ↑ 27 ; followup: ↓ 29 Changed 3 years ago by
Replying to ncohen:
oops. Anyhow, I merely wanted the actual calls to that
designs...._LJCR
be shown in the docs somewhere.I still can't see the point of that. All we care about (all that the function promises) is that it returns "some" bibd. If that works, then it rolls.
Well, you seem to prefer to hide the knowhow how to use LJCR in this case. It's not fair to a user that might need to use it for a similar task.
We can try isomorphism testing, but I bet it is as slow as a turtle...
If it is, install 'bliss'. Should go way faster.
Nathann
comment:29 in reply to: ↑ 28 ; followup: ↓ 30 Changed 3 years ago by
Well, you seem to prefer to hide the knowhow how to use LJCR in this case.
The interface with LJCR has nothing to do with this function. There is no certitude that their entry will not change, there is no reason to carve in doctests that ours and theirs should match. This doctest tests more than the function claims, so it has no reason to be.
It's not fair to a user that might need to use it for a similar task.
Nobody will have to. With this addition, there is no BIBD to be found on LJCR that Sage cannot build alone:
sage: missing = [(v,k) for v in range(101) for k in range(1,v) if designs.balanced_incomplete_block_design(v,k,existence=True) is Unknown] sage: for v,k in missing: ....: try: ....: designs.balanced_incomplete_block_design(v,k,use_LJCR=True) ....: print "found" ....: except: ....: pass ....: sage:
Do you intend to remove/fix the commit that contains the 'None == None' tests?
Nathann
comment:30 in reply to: ↑ 29 Changed 3 years ago by
 Branch changed from public/18934 to u/ncohen/18934
 Commit changed from 819bfa02346262814a0ff5ef3a9831eda7579739 to 6ed1abf670cc7212d0f287458bd3af9588adf21c
 Status changed from needs_review to positive_review
Replying to ncohen:
Well, you seem to prefer to hide the knowhow how to use LJCR in this case.
The interface with LJCR has nothing to do with this function. There is no certitude that their entry will not change, there is no reason to carve in doctests that ours and theirs should match. This doctest tests more than the function claims, so it has no reason to be.
It's not fair to a user that might need to use it for a similar task.
Nobody will have to. With this addition, there is no BIBD to be found on LJCR that Sage cannot build alone:
sage: missing = [(v,k) for v in range(101) for k in range(1,v) if designs.balanced_incomplete_block_design(v,k,existence=True) is Unknown] sage: for v,k in missing: ....: try: ....: designs.balanced_incomplete_block_design(v,k,use_LJCR=True) ....: print "found" ....: except: ....: pass ....: sage:Do you intend to remove/fix the commit that contains the 'None == None' tests?
never mind. You get your branch back :)
comment:31 Changed 3 years ago by
Thanks !
comment:32 Changed 3 years ago by
 Branch changed from u/ncohen/18934 to 6ed1abf670cc7212d0f287458bd3af9588adf21c
 Resolution set to fixed
 Status changed from positive_review to closed
New commits:
trac #18934: new BIBD: (91,7,1), (66,6,1), (76,6,1), (96,6,1)