论文标题
平行直接的特征索,用于遗体特征值问题的序列,没有三型分子化
A Parallel Direct Eigensolver for Sequences of Hermitian Eigenvalue Problems with No Tridiagonalization
论文作者
论文摘要
在本文中,提出了一个平行的直接特征索,用于赫米尔族特征值问题,没有提出\ texttt {pdeShep},并表示没有三角的序列,并将直接方法与迭代方法相结合。 \ texttt {pdeShep}首先将赫米尔矩阵缩小为带状形式,然后将频谱切片算法应用于带状矩阵,最后通过Backtransform计算原始矩阵的特征向量。因此,与常规的直接eigensolvers相比,\ texttt {pdeshep}避免了tridiagonalization,其中由许多内存的操作组成。在这项工作中,\ texttt {pdeshep}中的迭代方法基于盛宴中实现的轮廓积分方法。直接方法与迭代矩阵的迭代方法的组合需要一些有效的数据重新分布算法,从2D到1D以及从1D到2D数据结构。因此,提出了一些两步数据重新分布算法,比scalapack例程\ texttt {pxgemr2d}可以比$ 10 \ times $ $ $ $。对于对称的自符合字段(SCF)特征值问题,\ texttt {pdeShep}平均可以比使用$ 4096 $流程时的ELPA中最先进的直接求解器快$ 1.25 \ tims $ $。来自真实应用的密集遗传学矩阵以及套件藏品中的大型稀疏矩阵获得了数值结果。
In this paper, a Parallel Direct Eigensolver for Sequences of Hermitian Eigenvalue Problems with no tridiagonalization is proposed, denoted by \texttt{PDESHEP}, and it combines direct methods with iterative methods. \texttt{PDESHEP} first reduces a Hermitian matrix to its banded form, then applies a spectrum slicing algorithm to the banded matrix, and finally computes the eigenvectors of the original matrix via backtransform. Therefore, compared with conventional direct eigensolvers, \texttt{PDESHEP} avoids tridiagonalization, which consists of many memory-bounded operations. In this work, the iterative method in \texttt{PDESHEP} is based on the contour integral method implemented in FEAST. The combination of direct methods with iterative methods for banded matrices requires some efficient data redistribution algorithms both from 2D to 1D and from 1D to 2D data structures. Hence, some two-step data redistribution algorithms are proposed, which can be $10\times$ faster than ScaLAPACK routine \texttt{PXGEMR2D}. For the symmetric self-consistent field (SCF) eigenvalue problems, \texttt{PDESHEP} can be on average $1.25\times$ faster than the state-of-the-art direct solver in ELPA when using $4096$ processes. Numerical results are obtained for dense Hermitian matrices from real applications and large real sparse matrices from the SuiteSparse collection.