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-   -   BICGSTAB, MINRES, GMRES, ORTHOMIN??? (https://www.cfd-online.com/Forums/main/4821-bicgstab-minres-gmres-orthomin.html)

carlos June 11, 2002 11:22

BICGSTAB, MINRES, GMRES, ORTHOMIN???
 
Hi,

just a little question; for a stokes solver,

In almost all the bibliographical FEM articles, I have seen that is mentioned always the GMRES and the BICGSTAB methods as solvers, but in another book I had found the algorithms Orthomin and Orthores, which I did not know them very well, but its algorithms are easy to implement.

Someone can tell me if they are a good alternative to the previous ones, and if they work for not non-symmetric problems?

Thank you very much,

Carlos

Sebastien Perron June 12, 2002 19:52

Re: BICGSTAB, MINRES, GMRES, ORTHOMIN???
 
A good rule of thumb that I used:

1) Symmetric system with a dominant diagonal: conjugate gradient or orthomin2

2) Non-Symmetric system with a dominant diagonal: orthomin2

3) else: gmres

For the code I wrote when completing me thesis, I always used that rule and it never fails. ( I must be lucky...)


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