m-step preconditioners for nonhermitian positive definite Toeplitz systems
It is known that if A is a Toeplitz matrix，then A enjoys a circulant and skew circulant splitting(de— noted by CSCS)，i．e．，A=C+ S with C a circulant matrix and S a skew circulant matrix． Based on the CSCS iteration，we give m-step preconditioners P for certain classes of Toeplitz matrices in this pape...
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| Other Authors: | , , |
| Format: | article |
| Language: | eng |
| Published: |
2016
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| Subjects: | |
| Online Access: | http://hdl.handle.net/1822/50409 |
| Country: | Portugal |
| Oai: | oai:repositorium.sdum.uminho.pt:1822/50409 |
| Summary: | It is known that if A is a Toeplitz matrix，then A enjoys a circulant and skew circulant splitting(de— noted by CSCS)，i．e．，A=C+ S with C a circulant matrix and S a skew circulant matrix． Based on the CSCS iteration，we give m-step preconditioners P for certain classes of Toeplitz matrices in this paper．We show that if both C and S are positive definite，then the spectrum of the preconditioned matrix(PA)^* PA are clustered around one for some moderate size ． Experimental results show that the proposed preconditioners perform slightly better than T．Chan’S preconditioners for some moderate size m． |
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