Distance descending ordering method: An O(n) algorithm for inverting the mass matrix in simulation of macromolecules with long branches
| Autor: | Xiankun Xu, Peiwen Li |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Physics and Astronomy (miscellaneous)
FOS: Physical sciences Single-entry matrix Incomplete Cholesky factorization 010402 general chemistry 01 natural sciences law.invention Matrix decomposition Combinatorics law 0103 physical sciences Applied mathematics Symmetric matrix Mathematics Sparse matrix Numerical Analysis 010304 chemical physics Applied Mathematics Minimum degree algorithm Computational Physics (physics.comp-ph) LU decomposition 0104 chemical sciences Computer Science Applications Computational Mathematics Modeling and Simulation Physics - Computational Physics Cholesky decomposition |
| Zdroj: | Journal of Computational Physics. 349:253-264 |
| ISSN: | 0021-9991 |
| Popis: | Fixman's work in 1974 and the follow-up studies have developed a method that can factorize the inverse of mass matrix into an arithmetic combination of three sparse matrices—one of them is positive definite and needs to be further factorized by using the Cholesky decomposition or similar methods. When the molecule subjected to study is of serial chain structure, this method can achieve O ( n ) time complexity. However, for molecules with long branches, Cholesky decomposition about the corresponding positive definite matrix will introduce massive fill-in due to its nonzero structure. Although there are several methods can be used to reduce the number of fill-in, none of them could strictly guarantee for zero fill-in for all molecules according to our test, and thus cannot obtain O ( n ) time complexity by using these traditional methods. In this paper we present a new method that can guarantee for no fill-in in doing the Cholesky decomposition, which was developed based on the correlations between the mass matrix and the geometrical structure of molecules. As a result, the inverting of mass matrix will remain the O ( n ) time complexity, no matter the molecule structure has long branches or not. |
| Databáze: | OpenAIRE |
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