Title
Glued Matrices and the MRRR Algorithm
Abstract
During the last ten years, Dhillon and Parlett devised a new algorithm (multiple relatively robust representations (MRRR)) for computing numerically orthogonal eigenvectors of a symmetric tridiagonal matrix $T$ with $\mathcal{O}(n^2)$ cost. It has been incorporated into LAPACK version 3.0 as routine {\sc stegr}.We have discovered that the MRRR algorithm can fail in extreme cases. Sometimes eigenvalues agree to working accuracy and MRRR cannot compute orthogonal eigenvectors for them. In this paper, we describe and analyze these failures and various remedies.
Year
DOI
Venue
2005
10.1137/040620746
SIAM J. Scientific Computing
Keywords
Field
DocType
mrrr algorithm,numerically orthogonal eigenvectors,multiple relatively robust representations,new algorithm,orthogonal eigenvectors,tight clusters of eigenvalues,lapack version,various remedy,extreme case,glued matrices,robust representation,wilkinson matrices,symmetric tridiagonal matrix,sc stegr,eigenvectors,eigenvalues,tridiagonal matrix
Tridiagonal matrix,Algebra,Matrix (mathematics),Algorithm,Wilkinson matrix,Symmetric matrix,Numerical analysis,Mathematics,Eigenvalues and eigenvectors
Journal
Volume
Issue
ISSN
27
2
1064-8275
Citations 
PageRank 
References 
13
1.26
4
Authors
3
Name
Order
Citations
PageRank
Inderjit S. Dhillon17601450.15
Beresford N. Parlett245060.59
Christof Vömel316817.80