Akademska digitalna zbirka SLovenije - logo
E-viri
  • A combinatorial algorithm f...
    Hirai, Hiroshi; Iwamasa, Yuni

    Mathematical programming, 09/2022, Letnik: 195, Številka: 1-2
    Journal Article

    In this paper, we consider the problem of computing the rank of a block-structured symbolic matrix (a generic partitioned matrix) Formula omitted, where Formula omitted is a Formula omitted matrix over a field Formula omitted and Formula omitted is an indeterminate for Formula omitted and Formula omitted. This problem can be viewed as an algebraic generalization of the bipartite matching problem and was considered by Iwata and Murota (SIAM J Matrix Anal Appl 16(3):719-734, 1995). Recent interests in this problem lie in the connection with non-commutative Edmonds' problem by Ivanyos et al. (Comput Complex 27:561-593, 2018) and Garg et al. (Found. Comput. Math. 20:223-290, 2020), where a result by Iwata and Murota implicitly states that the rank and non-commutative rank (nc-rank) are the same for this class of symbolic matrices. The main result of this paper is a simple and combinatorial Formula omitted-time algorithm for computing the symbolic rank of a Formula omitted-type generic partitioned matrix of size Formula omitted. Our algorithm is inspired by the Wong sequence algorithm by Ivanyos et al. for the nc-rank of a general symbolic matrix, and requires no blow-up operation, no field extension, and no additional care for bounding the bit-size. Moreover it naturally provides a maximum rank completion of A for an arbitrary field Formula omitted.