Hybridizing Nested Dissection and

نویسندگان

  • François Pellegrini
  • Jean Roman
  • Patrick Amestoy
چکیده

Minimum degree and nested dissection are the two most popular reordering schemes used to reduce ll-in and operation count when factoring and solving sparse matrices. Most of the state-of-the-art ordering packages hybridize these methods by performing incomplete nested dissection and ordering by minimum degree the subgraphs associated with the leaves of the separation tree, but most often only loose couplings have been achieved, resulting in poorer performance than could have been expected. This paper presents a tight coupling of the nested dis-section and halo approximate minimum degree algorithms, which allows the minimum degree algorithm to use exact degrees on the boundaries of the subgraphs passed to it, and to yield back not only the ordering of the nodes of the subgraph, but also the amalgamated assembly subtrees, for eecient block computations. Experimental results show the performance improvement of this hy-bridization, both in terms of ll-in reduction and increase of concurrency on a parallel sparse block symmetric solver.

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Hybridizing Nested Dissection and Halo Approximate Minimum Degree for Efficient Sparse Matrix Ordering

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تاریخ انتشار 1999