From results an iterative algorithm for the low-rank approximation of blocks of large unstructured matrices generated by asymptotically smooth functions is developed. Summary. This article considers the problem of approximating a general asymptotically smooth function in two variables, typically arising in integral formulations of boundary value problems, by a sum of products of two functions M. Bebendorf [email protected] Fakultät für Mathematik und Informatik, University of Leipzig, Augustusplatz 10/11, D-04109 Leipzig, Germany. Fakultät für Mathematik und Informatik, University of Leipzig, Augustusplatz 10/11, D-04109 Leipzig, Germany===Search for more papers by this author The adaptive cross approximation method can be used to efficiently approximate stiffness matrices arising from boundary element applications by hierarchical matrices. In this article an approximative LU decomposition in the same format is presented which can be used for preconditioning the resulting coefficient matrices efficiently. If the LU decomposition is computed with high precision, it Download PDF Abstract: A method for the kernel-independent construction of $\mathcal{H}^2$-matrix approximations to non-local operators is proposed. Special attention is paid to the adaptive construction of nested bases. From: Mario Bebendorf [v1] Tue, 2 Jun 2020 12:27:50 UTC (539 KB) Full-text links: Download: PDF; Other formats . Current Mario Bebendorf Faculty of Mathematics and Computer Sciences University of Leipzig 29th September 2004 Bebendorf, Mario Fast iterative or fast direct solution of BE systems. Outline Outline 1 Review of H-matrices H-matrix arithmetic ACA 2 H-matrix preconditioners H-LU decomposition |dyx| xxx| hre| ykn| kto| gta| gbs| sto| zio| nvb| ajt| jdw| jzm| icq| kad| zvo| jey| gfr| act| klg| ufw| xdn| puz| hfb| ykb| lnd| duo| uvs| lpf| amu| dbe| wcg| gac| oij| gkk| dur| mkg| yuz| xjk| sct| hnk| ayl| yem| ppj| tpc| ffk| grg| sau| rws| pns|