## Heuristics for a matrix symmetrization problem

### Bora Uçar

Abstract.
We consider the following problem: given a square, nonsymmetric,
(0,1)-matrix, find a permutation of its columns that yields a
zero-free diagonal and maximizes the symmetry. The problem is known to
be NP-hard. We propose a fast iterative-improvement based heuristic
and evaluate the performance of the heuristic on a large set of
matrices.

Key words. unsymmetric sparse matrices, bipartite matching, matrix symmetrization.