#16884: Quasi-difference matrices (database+is_QDM)
-------------------------------------+-------------------------------------
Reporter: ncohen | Owner:
Type: enhancement | Status: needs_info
Priority: major | Milestone: sage-6.4
Component: combinatorial | Resolution:
designs | Merged in:
Keywords: | Reviewers:
Authors: Nathann Cohen | Work issues:
Report Upstream: N/A | Commit:
Branch: public/16884 | f0b7bab049e078a663702a935ea5f09facd396ed
Dependencies: #16879 | Stopgaps:
-------------------------------------+-------------------------------------
Changes (by vdelecroix):
* status: needs_review => needs_info
Comment:
Replying to [comment:11 ncohen]:
> > 2) You did not modify the doctests, is it on purpose
>
> Nonono it is a mistake, I first wrote those functions when we had no
`is_quasi_difference_matrix` function and I had no other choice. It is
fixed. Plus the '0' in the functions was actually a 1 and I had forgotten
to update it.
>
> I also changed the layout of the QDM dictionary: as for other
dictionaries, the 'k' is a key.
You mean a value I gues. As the code is
{{{
for ((n,k,lmbda,mu,u),f) in [...]:
if not (n+u,lmbda) in QDM:
QDM[n+u,lmbda] = {}
QDM[n+u,lmbda][n,lmbda,mu,u] = (k,f)
}}}
> And after the Brouwer-van Rees construction is reviewed I will have to
thing hard about a `find_*` function. The good news is that it should make
many - disappear `:-P`
You can also set the values by hand (but still try hard to find more
values).
More comments:
3) When there does exist a good `QDM` to build an `OA(k,n)`, could we use
`_OA_cache_set(kk,n,True)` instead of `_OA_cache_set(k,n,True)`. We will
win some few calls (especially when running `MOLS_table`).
4) I wonder if such things as 3) above is doable with `difference_matrix`
as well. For example we could put a call to `_OA_cache_set` inside
`difference_matrix` to set the existence to a potentially bigger `k`.
Alternatively, one can write
`_OA_cache_set(n,difference_matrix(n,None,existence=True))` in the core of
`orthogonal_array` but it might be slower.
Vincent
--
Ticket URL: <http://trac.sagemath.org/ticket/16884#comment:15>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.
