[Getdp] iterative method

Lin Ji jil at rpi.edu
Sun Nov 4 23:21:10 CET 2001


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)