Opened 6 years ago
Closed 6 years ago
#16922 closed enhancement (fixed)
find_brouwer_van_rees_with_one_truncated_column
Reported by:  ncohen  Owned by:  

Priority:  major  Milestone:  sage6.4 
Component:  combinatorial designs  Keywords:  
Cc:  vdelecroix  Merged in:  
Authors:  Nathann Cohen  Reviewers:  Vincent Delecroix 
Report Upstream:  N/A  Work issues:  
Branch:  955b67f (Commits)  Commit:  955b67f0cf7f5f0e584a8f7fb0d3520c675fc37e 
Dependencies:  #16920  Stopgaps: 
Description
Here is what we have been waiting for. Removes a lot of '', but in parts of the table that we do not see :P
Change History (16)
comment:1 Changed 6 years ago by
 Branch set to public/16922
 Status changed from new to needs_review
comment:2 Changed 6 years ago by
 Commit set to 822f174b04d1fbea062e4431bbba4a95215c4071
comment:3 Changed 6 years ago by
 Status changed from needs_review to needs_work
Hi Nathann,
I got a lot of segmentation error while running the tests with this branch! Do you know what happen?
Vincent
comment:4 Changed 6 years ago by
 Status changed from needs_work to needs_review
Sorry about that. Don't know where the segfaults came from, but when I solved the bug about the "more than 4 values needed to unpack" there was none left.
Also, I rewrote history to move this last commit above its dependencies (in which commits had been added in the meantime).
This should be better now.
By the way: the current implementation may look a bit "hacky". The thing is that it is 'a bit too early' to implement this construction, because at the moment there are no 'nice' functions to query the database of incomplete orthogonal arrays, and there is none yet because caching incomplete orthogonal arrays is much harder than caching orthogonal arrays (more parameters, mainly !). In the future we may even have find functions for incomplete orthogonal arrays and stuff.
Well, I have to write that and because it is not exactly straightforward to get a good design (and because it requires a lot of 'administrative' code) I implemented that first.
Still, it works and it is not so bad.
Well, just know that I am not intending to leave that code in the current state. Though I tried to not make it too awful either, and of course the review is there to fix anything you will not like.
Branch updated.
Nathann
comment:5 Changed 6 years ago by
 Commit changed from 822f174b04d1fbea062e4431bbba4a95215c4071 to 0d26d101552d5c279f849f17fbc7186a421d709e
Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:
9b8ba79  trac #16559: Fixes reported by Julian R. Abel

b0419b8  trac #16559: Merged with 6.4.beta6

fe62ae4  trac #16559: Bugfix

12177d8  trac #16559: fix documentation

3825155  trac #16559: remove simple_wilson_construction

9bbd1f2  trac #16559: A description for the Brouwervan Rees construction

cf90906  trac #16920: Correct bibliographical references

cf378ab  trac #16920: Merged with updated #16559

0d26d10  trac #16922: find_brouwer_van_rees_with_one_truncated_column

comment:6 Changed 6 years ago by
 Commit changed from 0d26d101552d5c279f849f17fbc7186a421d709e to b71013a5ffb081f77fc8a0a75338c8a39c3a378c
Branch pushed to git repo; I updated commit sha1. New commits:
b71013a  trac #16922: big optim. + small optim. + doctest

comment:7 followups: ↓ 8 ↓ 9 Changed 6 years ago by
Hi Nathann,
I changed the complexity of multiple
by one order. And we can win more by cutting some of the branches (if I got the value v
in m
steps then I can not be bigger than v + (km) max_value
at the end).
Have a look and tell me if it is worth it to add this cut.
Vincent
comment:8 in reply to: ↑ 7 Changed 6 years ago by
I changed the complexity of
multiple
by one order.
True, True. Well done O_o
And we can win more by cutting some of the branches (if I got the value
v
inm
steps then I can not be bigger thanv + (km) max_value
at the end).
Well, technically can't we do it with log(k)
iterations instead of k
?
I mean, if you call S^n={x_1+...+x_n: x_i \in S}
then you can use the log algorithm to compute the power of a matrix, can't you ? And you can do even faster is you initialize D
with D = {r*x:tuple([x]*r) for x in S for r in tuple(range(cutoff/x+1))}
.
Keep in mind that this function will change, somehow. I mean... If we want to be able to do the same for the Brouwervan Rees decomposition with 2 truncated columns, the problem is very different: in each column you can have any combinations of 'allowed value', but you cannot have a multiplier x in column 1 and a multiplier y in column 2 unless you have an OA(k,m+x+y)OA(k,x)OA(k,y)
.
I still don't know how to write that nicely T_T
Nathann
comment:9 in reply to: ↑ 7 Changed 6 years ago by
Yo !
Have a look and tell me if it is worth it to add this cut.
It is up to you. I am not sure that it is necessary at the moment: I hope that this will all be rewritten in not so long to handle two columns.
Nathann
comment:10 Changed 6 years ago by
 Commit changed from b71013a5ffb081f77fc8a0a75338c8a39c3a378c to 955b67f0cf7f5f0e584a8f7fb0d3520c675fc37e
Branch pushed to git repo; I updated commit sha1. New commits:
955b67f  trac #16922: rewrite multiple (new name int_as_sum)

comment:11 Changed 6 years ago by
All right. Done.
I find it much clearer. Perhaps less nicer to make it works for two columns...
Vincent
comment:12 followup: ↓ 13 Changed 6 years ago by
What is the point of making it decrease toward zero ? O_o
To have more meaningful comments like
if (vv > 0 and # The new integer i is too big
?
Honestly I do not care, this will be rewritten soon anyway. But why would you do something like that ?
You even do for j in range(k1,1,1)
which is totally equivalent to for j in range(k)
given that you do not use j. Only to make it more complicated ?...
Nathann
comment:13 in reply to: ↑ 12 Changed 6 years ago by
Replying to ncohen:
What is the point of making it decrease toward zero ?
O_o
To have more meaningful comments like
if (vv > 0 and # The new integer i is too big
?Honestly I do not care, this will be rewritten soon anyway. But why would you do something like that ?
You even do
for j in range(k1,1,1)
which is totally equivalent tofor j in range(k)
given that you do not use j. Only to make it more complicated ?...
Hum. j
is useful as it is the remaining number of steps and allow to cut branches when the maximum number of steps allowed (i.e. k_max
) is relatively small.
+ if (vv > 0 and # The new integer i is too big + vv <= j*max_value and # The new integer i is too small + vv not in D and # We had it in D already + vv not in new_D): # We had it in new_D already
Vincent
comment:14 Changed 6 years ago by
This code is awful.
Anyway, I will rewrite it soon.
Nathann
comment:15 Changed 6 years ago by
 Reviewers set to Vincent Delecroix
 Status changed from needs_review to positive_review
comment:16 Changed 6 years ago by
 Branch changed from public/16922 to 955b67f0cf7f5f0e584a8f7fb0d3520c675fc37e
 Resolution set to fixed
 Status changed from positive_review to closed
Branch pushed to git repo; I updated commit sha1. Last 10 new commits:
trac #16884: A database entry for Quasidifference matrices. +doc and stuff
trac #16884: Convert OA(9,514) into a Vmt
trac #16884: is_quasi_difference_matrix
trac #16884: A V(12,185) that yields a OA(11,2406)
trac #16559: BrouwerVan Rees version of Wilson's decomposition
trac #16559: Fixed error message for large holes and smaller example
trac #16920: New V(m,t) vectors
trac #16920: Make the V(m,t) database more compact
trac #16920: Even more MOLS
trac #16922: find_brouwer_van_rees_with_one_truncated_column