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arXiv 2302.07565math.NAcs.NA
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矩阵$ϕ$ -低阶函数的有效逆

Efficient Inversion of Matrix $ϕ$-Functions of Low Order

L. Gemignani

摘要:

本文研究求解线性方程组$ϕ(A) x= b$的有效数值方法,其中$ϕ(z)$是$ϕ$ -函数,$A\in \mathbb R^{N\times N}$ .特别是在这项工作中,我们感兴趣的情况下,$ϕ(z)=ϕ_1(z)=\displaystyle\frac{e^z-1}{z}, \quad ϕ(z)=ϕ_2(z)=\displaystyle\frac{e^z-1-z}{z^2}$的${ϕ(A)}^{-1} b$的计算。在适当的条件下,$A$的频谱,我们设计的快速算法计算${ϕ_\ell(A)}^{-1}$和${ϕ_\ell(A)}^{-1} b$基于牛顿迭代和Krylov型方法,分别。适应这些计划的结构矩阵被认为是。特别是带状和更一般的quasiseparable矩阵的情况下进行了研究。数值结果表明,我们提出的算法的有效性。

英文摘要:

The paper is concerned with efficient numerical methods for solving a linear system $ϕ(A) x= b$, where $ϕ(z)$ is a $ϕ$-function and $A\in \mathbb R^{N\times N}$. In particular in this work we are interested in the computation of ${ϕ(A)}^{-1} b$ for the case where $ϕ(z)=ϕ_1(z)=\displaystyle\frac{e^z-1}{z}, \quad ϕ(z)=ϕ_2(z)=\displaystyle\frac{e^z-1-z}{z^2}$. Under suitable conditions on the spectrum of $A$ we design fast algorithms for computing both ${ϕ_\ell(A)}^{-1}$ and ${ϕ_\ell(A)}^{-1} b$ based on Newton's iteration and Krylov-type methods, respectively. Adaptations of these schemes for structured matrices are considered. In particular the cases of banded and more generally quasiseparable matrices are investigated. Numerical results are presented to show the effectiveness of our proposed algorithms.

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。

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