A computable error bound for matrix functionals
โ Scribed by D. Calvetti; G.H. Golub; L. Reichel
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 243 KB
- Volume
- 103
- Category
- Article
- ISSN
- 0377-0427
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โฆ Synopsis
Many problems in applied mathematics require the evaluation of matrix functionals of the form F(A):= uTf(A)u, where A is a large symmetric matrix and u is a vector. Golub and collaborators have described how approximations of such functionals can be computed inexpensively by using the Lanczos algorithm. The present note shows that error bounds for these approximations can be computed essentially for free when bounds for derivatives of f on an interval containing the spectrum of A are available. (~) 1999 Elsevier Science B.V. All rights reserved.
๐ SIMILAR VOLUMES
An error bound for approximate eigenvalues of a complex n-dimensional pencil (A, B) is given. From our theorem several well-known bounds follow as corollaries. Our result takes into account the general residual AX -BXW, where X ~ C n x m and W ~ C mxm with m ~< n.