Fast Sparse Selected Inversion
Fast Sparse Selected Inversion
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快速稀疏选择反演
DOI:
--
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发表时间:
2015
影响因子:
1.5
通讯作者:
V. Balakrishnan
中科院分区:
文献类型:
--
作者:
J. Xia;Yuanzhe Xi;S. Cauley;V. Balakrishnan
We propose a fast structured selected inversion method for extracting the diagonal blocks of the inverse of a sparse symmetric matrix $A$, using the multifrontal method and rank structures. When $A$ arises from the discretization of some PDEs and has a low-rank property (the intermediate dense matrices in the factorization have small off-diagonal numerical ranks), structured approximations of the diagonal blocks and certain off-diagonal blocks of $A^{-1}$ (that are needed to find the diagonal blocks of $A^{-1}$) can be quickly computed. A structured multifrontal LDL factorization is first computed for $A$ with a forward traversal of an assembly tree, which yields a sequence of local data-sparse factors. The factors are used in a backward traversal of the tree for the structured inversion. The intermediate operations in the inversion are performed in hierarchically semiseparable or low-rank forms. With the assumptions of data sparsity and appropriate rank conditions, the theoretical structured inversion co...