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In this paper, the aim is to symmetrically permute the rows and columns of a given sparse symmetric matrix so that the profile of the permuted matrix is minimized. We formulate this permutation problem by first defining the m-way ordered hypergraph partitioning (moHP) problem and then showing the correspondence between profile minimization and moHP problems. For solving the moHP problem, we propose a recursive-bipartitioning-based hypergraph partitioning algorithm, which we refer to as the moHP algorithm. This algorithm achieves a linear part ordering via left-to-right bipartitioning. In this algorithm, we utilize fixed vertices and two novel cut-net manipulation techniques in order to address the minimization objective of the moHP problem. We show the correctness of the moHP algorithm and describe how the existing partitioning tools can be utilized for its implementation. Experimental results on an extensive set of matrices show that the moHP algorithm obtains a smaller profile than the state-of-the-art profile reduction algorithms, which then results in considerable improvements in the factorization runtime in a direct solver. [ABSTRACT FROM AUTHOR]

We investigate the problem of symmetrically permuting a square sparse matrix into a block diagonal form with overlap. This permutation problem arises in the parallelization of an explicit formulation of the multiplicative Schwarz preconditioner and a more recent block overlapping banded linear solver as well as its application to general sparse linear systems. In order to formulate this permutation problem as a graph theoretical problem, we define a constrained version of the multiway graph partitioning by vertex separator (GPVS) problem, which is referred to as the ordered GPVS (oGPVS) problem. However, existing graph partitioning tools are unable to solve the oGPVS problem. So, we also show how the recursive bipartitioning framework can be utilized for solving the oGPVS problem. For this purpose, we propose a left-to-right bipartitioning approach together with a novel vertex fixation scheme so that existing 2-way GPVS tools that support fixed vertices can be effectively and efficiently utilized in the recursive bipartitioning framework. Experimental results on a wide range of matrices confirm the validity of the proposed approach. [ABSTRACT FROM AUTHOR]