Yoooooooooooooooooooo !! But, of course, this design extends uniquely to a (necessarily) 2-(4n, 2n, > n-1) design: the blocks of this design are blocks of the old design union a > new point infinity and complements (in the old point set) of the blocks of > old design. And, any contraction is isomorphic to a Hadamard 2-design we > started off with. So, unsurprisingly, this family is called Hadamard > 3-designs. > > As you see, implementing the 3-design is trivial but we should settle down > on the nomenclature! >
I did not know about this construction, but the Handbook agrees with you, so why not ? :-D By the way your proof of it is very cool. So, what do you guys think? > Do you feel like creating a ticket and writing this patch ? I will be glad to review it quickly. p/s/ Thanks Nathann for implementing the combinat.designs! I am a big fan > of designs and it is nice to have them in SAGE. > Well, I am pretty glad that you noticed the changes and that you like them. If you have time to review some code, there are a couple of things that are still waiting on the trac server : A straightforward one : http://trac.sagemath.org/ticket/16091 A more interesting one : http://trac.sagemath.org/ticket/15310 (Vincent just reviewed http://trac.sagemath.org/ticket/15431 ) The second one is a very interesting recursive construction that I need to add the general construction of BIBD with k=5 (which already works on my computer). There will also be a need for a patch that just cleans the code in between before that. Well, this just to say that if you feel like getting your hands dirty for Sage's designs... ;-) Have fuuuuuuuuuuuun ! Nathann -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
