On the numerical approximation of the distance to singularity for matrix-valued functions

Fuente: arXiv
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Hauptverfasser: Gnazzo, Miryam, Guglielmi, Nicola
Format: Preprint
Veröffentlicht: 2023
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author Gnazzo, Miryam
Guglielmi, Nicola
author_facet Gnazzo, Miryam
Guglielmi, Nicola
contents Given a matrix-valued function $\mathcal{F}(λ)=\sum_{i=1}^d f_i(λ) A_i$, with complex matrices $A_i$ and $f_i(λ)$ entire functions for $i=1,\ldots,d$, we discuss a method for the numerical approximation of the distance to singularity of $\mathcal{F}(λ)$. The closest singular matrix-valued function $\widetilde{\mathcal{F}}(λ)$ with respect to the Frobenius norm is approximated using an iterative method. The property of singularity on the matrix-valued function is translated into a numerical constraint for a suitable minimization problem. Unlike the case of matrix polynomials, in the general setting of matrix-valued functions the main issue is that the function $\det ( \widetilde{\mathcal{F}}(λ) )$ may have an infinite number of roots. An important feature of the numerical method consists in the possibility of addressing different structures, such as sparsity patterns induced by the matrix coefficients, in which case the search of the closest singular function is restricted to the class of functions preserving the structure of the matrices.
format Preprint
id arxiv_https___arxiv_org_abs_2309_01220
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle On the numerical approximation of the distance to singularity for matrix-valued functions
Gnazzo, Miryam
Guglielmi, Nicola
Numerical Analysis
65F99, 15A18, 47A56, 65K05
Given a matrix-valued function $\mathcal{F}(λ)=\sum_{i=1}^d f_i(λ) A_i$, with complex matrices $A_i$ and $f_i(λ)$ entire functions for $i=1,\ldots,d$, we discuss a method for the numerical approximation of the distance to singularity of $\mathcal{F}(λ)$. The closest singular matrix-valued function $\widetilde{\mathcal{F}}(λ)$ with respect to the Frobenius norm is approximated using an iterative method. The property of singularity on the matrix-valued function is translated into a numerical constraint for a suitable minimization problem. Unlike the case of matrix polynomials, in the general setting of matrix-valued functions the main issue is that the function $\det ( \widetilde{\mathcal{F}}(λ) )$ may have an infinite number of roots. An important feature of the numerical method consists in the possibility of addressing different structures, such as sparsity patterns induced by the matrix coefficients, in which case the search of the closest singular function is restricted to the class of functions preserving the structure of the matrices.
title On the numerical approximation of the distance to singularity for matrix-valued functions
topic Numerical Analysis
65F99, 15A18, 47A56, 65K05
url https://arxiv.org/abs/2309.01220