Hadamard equivalence via graph isomorphism

✍ Scribed by Brendan D. McKay

• Publisher: Elsevier Science
• Year: 1979
• Tongue: English
• Weight: 180 KB
• Volume: 27
• Category: Article
• ISSN: 0012-365X
• DOI: 10.1016/0012-365x(79)90113-4

✦ Synopsis

Two ~1 x n matrices with f I entries are H rdamard equivalent if one may be obtained from the other by a sequence of operations involvir g independent row and column permutations and multiplications of rows or columns by -1. We solve the computational problem of recognising Hadamard equivalence by reducing it to the problem of determining an isomorphism between two graphs with 2(rn + tt) vertices, Existing graph isomorphism algorithms permit the practical determination of Hadamard equivalence when nt and n are of the order of several hundred.