Title
A Variant of the ORTHOMIN(2) Method for Singular Linear Systems
Abstract
For singular linear systems Ax=b, ORTHOMIN(2) is known theoretically to attain the minimum residual min?x?Rn?b-Ax?2 under a certain condition. However, in the actual computation with finite precision arithmetic, the residual is often observed to be reduced further than the theoretically expected level. Therefore, we propose a variant of ORTHOMIN(2), which is mathematically equivalent to the original ORTHOMIN(2) method, but uses recurrence formulas that are different from those of ORTHOMIN(2); they contain alternative expressions for the auxiliary vector and the recurrence coefficients. Although our implementation has the same computational costs as ORTHOMIN(2), numerical experiments on singular systems show that our implementation is more accurate and less affected by rounding errors than ORTHOMIN(2).
Year
DOI
Venue
2004
10.1023/B:NUMA.0000040047.81654.f5
Numerical Algorithms
Keywords
Field
DocType
Krylov subspace method,Orthomin(2) method,singular systems,two-dimensional minimization,minimum residual norm
Residual,Mathematical optimization,Expression (mathematics),Singular linear systems,Mathematical analysis,Singular systems,Rounding,Mathematics,Computation
Journal
Volume
Issue
ISSN
36
3
1572-9265
Citations 
PageRank 
References 
2
0.67
4
Authors
4
Name
Order
Citations
PageRank
Kuniyoshi Abe1175.45
Shao-Liang Zhang29219.06
Taketomo Mitsui331.73
Cheng-Hai Jin420.67