#4341: [with patch, needs review] Optimisations + corrections to latin.py
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Reporter: carlohamalainen | Owner: mhansen
Type: enhancement | Status: new
Priority: minor | Milestone: sage-3.2.1
Component: combinatorics | Resolution:
Keywords: |
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Comment (by wdj):
Regarding the "to do" using nauty: please don't. Robert Miller's code NICE
does this fine:
{{{
sage: from sage.combinat.matrices.latin import *
sage: M = matrix([(0, 1, 2, 3), (2, 3, 0, 1), (3, 2, 1, 0), (1, 0, 3, 2)])
sage: L = LatinSquare(M)
sage: L.is_latin_square()
True
sage: from sage.groups.perm_gps.partn_ref.refinement_matrices import
MatrixStruct
sage: A = MatrixStruct(M)
sage: autgp = A.automorphism_group()
sage: gens = [[j+1 for j in autgp[0][i]] for i in range(len(autgp[0]))]
sage: S4 = SymmetricGroup(4)
sage: G = PermutationGroup([S4(x) for x in gens]); G
Permutation Group with generators [(1,2)(3,4)]
}}}
An easy "to do": take the very short MOLS codes in Guava (included in
Sage), at
http://sage.math.washington.edu/home/wdj/guava/lib/matrices.gi,
and translate it into Python/Sage/latin.py code. (MOLS are used to
construct optimal non-linear codes, but non-linear codes have not yet been
implemented in Sage.)
I'm currently running tests on this (second) patch and will post again
soon.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/4341#comment:2>
Sage <http://sagemath.org/>
Sage - Open Source Mathematical Software: Building the Car Instead of
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