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  5. Generalizing the LINPACK Condition Estimator

Generalizing the LINPACK Condition Estimator

File(s)
81-462.pdf (900.57 KB)
81-462.ps (315.16 KB)
Permanent Link(s)
https://hdl.handle.net/1813/6302
Collections
Computer Science Technical Reports
Author
Cline, A. K.
Conn, Andrew R.
Van Loan, Charles
Abstract

Two generalizations of the Cline-Moler-Stewart-Wilkinson "LINPACK" condition estimator are described. One generalization combines the LINPACK notion of "look-ahead" with a new feature called "look-behind" that results in a more flexibly chosen right-hand side. The other generalization is a "divide-and-conquer" scheme that involves estimating the condition of certain principal submatrices whose dimension repeatedly doubles. Both generalizations require that maximization of simple objective functions. When seeking an $L_{1}$ condition estimate, these functions are convex while inthe $L_{2}$ case they are quadratic. All the algorithms considered appear to be at least as reliable as the LINPACK estimator and are equally efficient.

Date Issued
1981-06
Publisher
Cornell University
Keywords
computer science
•
technical report
Previously Published as
http://techreports.library.cornell.edu:8081/Dienst/UI/1.0/Display/cul.cs/TR81-462
Type
technical report

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