Anders Logg wrote:
> On Fri, May 16, 2008 at 10:55:09AM +0100, Nuno David Lopes wrote:
>> GMRES seems to work: 
>> -------------------------------------------------------------------------------------------------
>> Solving linear system of size 40121 x 40121 (uBlas Krylov solver).
>> Krylov solver converged in 14 iterations.
>> -------------------------------------------------------------------------------------------------
>> I've got the same results for factorized LU.
>>
>>
>> CG isn't recognized
> 
> CG isn't implemented for uBLAS. 

I'll add it once we can apply boundary conditions without destroying 
symmetry.

Check line 130 and onward in
> uBlasKrylovSolver.h.
> 
>> and  BiCGStab (the default) "doesn't converge"...
>> it makes only one iteration:
> 
> I'm not sure how well tested the BiCGStab implementation is, but it's
> not very unusual for an iterative method to not converge.
> 

BiCGStab was pretty well tested. Make sure that a preconditioner is 
being used, and if you're solving a steady diffusion problem, start 
testing with a coarse mesh. The iterative methods will struggle with 
steady diffusion and mesh refinement.

Garth


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