arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1806.07028math.NAcs.NA
收藏

基于路径覆盖的自适应多网格方法

An Adaptive Multigrid Method Based on Path Cover

Tufts University(塔夫茨大学);The Pennsylvania State University(宾夕法尼亚州立大学)

Xiaozhe Hu, Junyuan Lin, Ludmil T. Zikatanov

AI总结:

本文提出基于路径覆盖的自适应代数多网格方法,用于求解加权图拉普拉斯线性系统,并可应用于离散的二阶椭圆偏微分方程。该方法通过构建多级结构实现高效求解。

摘要:

我们提出了一种基于路径覆盖的自适应代数多网格(PC-αAMG)方法,用于求解加权图拉普拉斯线性系统,并可应用于离散的二阶椭圆偏微分方程。PC-αAMG基于未平滑聚合AMG(UA-AMG)。为了将平滑误差结构保持到粗化级别,我们通过形成顶点不相交的路径覆盖来近似平滑误差的水平集。然后通过在路径覆盖中匹配路径来构建聚合。这样,我们能够在较低的计算成本下构建多级结构。所提出的PC-αAMG提供了一种机制,在迭代过程中高效重建多级层次结构,从而导致快速的非线性多级算法。传统上,UA-AMG需要更复杂的循环技术,如AMLI-cycle或K-cycle,但根据我们的数值结果,所提出的PC-αAMG导致几乎最优的标准V-循环算法用于求解加权图拉普拉斯线性系统。一些真实世界图问题的数值实验也展示了PC-αAMG的有效性和鲁棒性,尤其是在处理病态图时。

英文摘要:

We propose a path cover adaptive algebraic multigrid (PC-$α$AMG) method for solving linear systems of weighted graph Laplacians and can also be applied to discretized second order elliptic partial differential equations. The PC-$α$AMG is based on unsmoothed aggregation AMG (UA-AMG). To preserve the structure of smooth error down to the coarse levels, we approximate the level sets of the smooth error by first forming vertex-disjoint path cover with paths following the level sets. The aggregations are then formed by matching along the paths in the path cover. In such manner, we are able to build a multilevel structure at a low computational cost. The proposed PC-$α$AMG provides a mechanism to efficiently re-build the multilevel hierarchy during the iterations and leads to a fast nonlinear multilevel algorithm. Traditionally, UA-AMG requires more sophisticated cycling techniques, such as AMLI-cycle or K-cycle, but as our numerical results show, the PC-$α$AMG proposed here leads to nearly optimal standard V-cycle algorithm for solving linear systems with weighted graph Laplacians. Numerical experiments for some real world graph problems also demonstrate PC-$α$AMG's effectiveness and robustness, especially for ill-conditioned graphs.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑