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Preconditioned conjugate gradient methods for the solution of indefinite least squares problems
The conjugate gradient (CG) method is considered for solving the large and sparse indefinite least squares (ILS) problem min x ( b − Ax ) T J ( b − Ax ) where J =diag ( I p ,− I q ) is a signature matrix. However the rate of convergence becomes slow for ill-conditioned problems. The QR-based precon...
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Published in: | Calcolo 2011-09, Vol.48 (3), p.261-271 |
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Main Authors: | , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | The conjugate gradient (CG) method is considered for solving the large and sparse indefinite least squares (ILS) problem min
x
(
b
−
Ax
)
T
J
(
b
−
Ax
) where
J
=diag (
I
p
,−
I
q
) is a signature matrix. However the rate of convergence becomes slow for ill-conditioned problems. The QR-based preconditioner is found to be effective in accelerating the convergence. Numerical results show that the sparse Householder QR-based preconditioner is superior to the CG method especially for sparse and ill-conditioned problems. |
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ISSN: | 0008-0624 1126-5434 |
DOI: | 10.1007/s10092-011-0039-8 |