[Getdp] iterative method

[Christophe Geuzaine]

I did not get the attachments. 

Try to precondition your system a bit more (i.e. increase the NbFill
parameter in the solver.par file).

Christophe

Lin Ji wrote:
> 
> Dear Christophe,
>     I am sorry to bother you again. I still can not make the Helmholtz
> equation solved correctly. It seems there is something wrong with the
> iterative method used to solve the linear system. I got the book 'Iterative
> Methods for Sparse Linear Systems'. But, it seems it requires quite a bit
> learning curve in order to understand the methods and the preconditioning
> technique. Can you take a look of my problem again? I would really appreciate
> it.
>     I attached 'hhltz.pro', 'hhltz.geo' and 'solver.par'. The following is
> the output of running getdp on hhltz.pro:
> 
> /personal/research/proj_rep/hhltz2D (66) ../../getdp-0.84/getdp hhltz -pre
> -cal -pos
> Loading   : Problem definition 'hhltz.pro'
> Info      : Available Resolutions
> (1) hhltz
> Choice: 1
> Info      : Available PostOperations
> (1) u
> Choice: 1
> Info      : Selected Resolution 'hhltz'
> Loading   : Geometric data 'hhltz.msh'
> Info      : System 'A' : Real
> P r e - P r o c e s s i n g . . .
> Operation : Treatment Formulation 'hhltz'
> Resources : cpu 11.670000 s / mem 0 kb
> E n d   P r e - P r o c e s s i n g
> P r o c e s s i n g . . .
> Operation : Generate[A]
> Solver    : Loading parameter file 'solver.par'
> Resources : cpu 47.360000 s / mem 0 kb
> Operation : Solve[A]
> Solver    : No scaling of system of equations
> Solver    : RCMK algebraic renumbering
> Solver    : N: 186723, NZ: 2140569, BW max/avg: 28/11, SW max: 186222
> Resources : cpu 52.100000 s / mem 0 kb
> Solver    : ILUTP (Float, fill-in = 20)
> Solver    : N: 186723, NZ: 6165203, BW max/avg: 40/33, SW max: 172178
> Resources : cpu 82.380000 s / mem 0 kb
> Solver    : Generalized Minimum RESidual (GMRES)
>    1  1.3449314e-01  1.0000000e+00
> Warning   : Iterative solver is facing a break-down
>    2  0.0000000e+00  0.0000000e+00
> Solver    : 2 Iterations / Residual: 0.134493
> Resources : cpu 83.890000 s / mem 0 kb
> Operation : SaveSolution[A]
> Resources : cpu 84.250000 s / mem 0 kb
> E n d   P r o c e s s i n g
> P o s t - P r o c e s s i n g . . .
> Info      : Selected PostProcessing 'hhltz'
> Info      : Selected Mesh 'hhltz.msh'
> Operation : PostOperation 1/1
>           > 'uh.pos'
> Info      : Initializing rapid search grid 20x20x1
> Resources : cpu 189.980000 s / mem 0 kb
> E n d   P o s t - P r o c e s s i n g
> E n d
> 
> Best regards,
> 
> Lin
> 
> --
> Dept. of Math., RPI
> 518-276,6904 (work)
> _______________________________________________
> GetDP mailing list
> GetDP at geuz.org
> http://www.geuz.org/mailman/listinfo/getdp

-- 
Christophe Geuzaine

Tel: 32 (0) 4 366 37 10    http://geuz.org
Fax: 32 (0) 4 366 29 10    mailto:Christophe.Geuzaine at ulg.ac.be