Specify the values of k,n in the exceptions

[nathanncohen]

Simple thing, that can be useful for recursive constructions. You don't always know what "this" design exactly is in complicated functions.

Nathann

CC: @videlec @KPanComputes @brettpim

Component: combinatorial designs

Author: Nathann Cohen

Branch/Commit: 79178b6

Reviewer: Vincent Delecroix

Issue created by migration from https://trac.sagemath.org/ticket/16388

[nathanncohen]

Branch: u/ncohen/16388

[sagetrac-git]

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

767e091

trac #16388: Specify the values of k,n in the exceptions

[sagetrac-git]

Commit: 767e091

[videlec]

comment:3

Hi Nathann,

All right, why not doing it for BIBD as well?

Vincent

[nathanncohen]

comment:4

Indeed. You can add a commit.

Nathann

[videlec]

comment:5

I can do that, but I do care about merge conflicts with other tickets.

[nathanncohen]

comment:6

I can do that, but I do care about merge conflicts with other tickets.

Caring is good. Do you have a specific ticket in mind ?

Nathann

[videlec]

comment:7

For example #16347 (Wilson's constructions of OA with 2 truncated groups) modifies bibd.py

[nathanncohen]

comment:8

For example #16347 (Wilson's constructions of OA with 2 truncated groups) modifies bibd.py

Indeed. You can see that none of the lines near where the exceptions are raised or doctested are touched, so this is safe.

Nathann

[videlec]

comment:9

The two commits at u/vdelecroix/16388 take care of BIBD. All test pass. Can set to positive review if you like.

Vincent

[nathanncohen]

comment:10

Yo !

The two commits at u/vdelecroix/16388 take care of BIBD. All test pass. Can set to positive review if you like.

I added a small commit as one usually writes (v,k,lambda)-BIBD.

Nathann

[sagetrac-git]

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

a460169	merge Sage version 6.3.beta3
c365a39	trac #16388: use format for OA + specify (k,n) for BIBD
ec26ca2	trac #16388: a missing one in BIBD_from_TD
79178b6	trac #16388: (v,k,1)-BIBD instead of BIBD(v,k,1)

[sagetrac-git]

Changed commit from 767e091 to 79178b6

[nathanncohen]

comment:12

By the way the modifications you did to the exception of OA/TD will probably cost a LOT of conflicts.

Just mentionning it because you said that you cared.

Nathann

[nathanncohen]

Reviewer: Vincent Delecroix

[nathanncohen]

comment:13

Oh, my mistake. Those modifications cannot hurt more than the patch did before you wrote this commit. Sorry for that.

I hope I had conflicts in mind when I first wrote it. Otherwise I will pay it.

Nathann

[videlec]

comment:14

The terminology is not understandable:

• MOLS(n,k) but TD(k,n)
• (v,k,lambda)-BIBD but TD(v,k,lambda)

good luck for your future merges... (now you are used to it ;-P)

Vincent

[nathanncohen]

comment:15

Yo !

The terminology is not understandable:

I just sent you "Combinatorial Designs: Construction and Analysis" from Douglas Stinson which uses (v,k,lambda)-BIBD, TD(k,n) and OA(k,n). I believed that the Handbook of Combinatorial Designs did the same but they actually write BIBD(v,k,lambda). Their purpose was probably to unify notations, given that (v,k,lambda)-BIBD is a pretty common :

http://www.maths.qmul.ac.uk/~leonard/repeated11.pdf
http://www.argilo.net/files/bibd.pdf

You will also find other occurrences of this naming in the references of the Handbook.

Othey guys say 2-(v,k,lambda) design.

• MOLS(n,k) but TD(k,n)
• (v,k,lambda)-BIBD but TD(v,k,lambda)

Two remarks :

• MOLS(n,k) does not appear in Sage's code
• It is true that the constructor of MOLS takes first a n then an k as input. It is true that it can lead to mistakes, and perhaps we should change it.
• If you insist on using BIBD(v,k,lambda) it can be done but it has to be a global change as some pages, eg http://sagemath.org/doc/reference/combinat/sage/combinat/designs/bibd.html already use this terminology. Same for PBD.

good luck for your future merges... (now you are used to it ;-P)

Nathann

[vbraun]

Changed branch from u/ncohen/16388 to 79178b6