[Nauty] graph for matrix automorphism

Pieter Eendebak pieter.eendebak at gmail.com
Fri Feb 12 00:58:46 AEDT 2016


Hi all,

On the nauty+traces webpage there are some examples of matrix ismorphism
problems formulated as a graph isomorphism problem (which can be solved by
nauty).

I am looking for a correspondence between matrices and graphs for the
following isomorphism.
We have matrices which have values +1, 0 and -1. Allowed matrix
transformations are row permutations, column permutations, negation of rows
and negation of columns.
(this is essentialy Hadamard equivalence with the addition of zeros in the
matrix)

As an alternative a correspondence between the matrix and a graph allowing
for row permutations, column permutations, permutation of the symbols in a
row and permutations of the symbols in a column will work for me. (because
of the numbers of 0's, +1 and -1's in the matrix I know that 0 cannot be
permuted to either +1 or -1).


With kind regards,
Pieter


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