DOLFIN

problem with Krylov on windows 7

Asked by Peter Franek

Hello, I installed fenics on windows 7 and tried to run the python navier-stokes.demo, but it crashed. This is the message:
-----------------------------
Error: Unable to solve linear system using Krylov iteration.
Reason: Unknownpreconditioner "amg". Use list_krylov_preconditioners() to list available preconditioners()
Where: this error was encountered inside KrylovSlover.cpp.
-----------------------------
Any hint what to do? Does it need some other package for those Krylov things? Thanks a lot, Peter

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Kent-Andre Mardal (kent-and) said : 		#1

If you look at the file you will see that the preconditioner (prec) is set
to algebraic multigrid
(amg), which is enabled by either Trilinos or PETSc with HYPER. You can set
prec
to e.g. "ilu" or "jacobi" instead if you don't want these packages.
See, the dolfin chapter in either the FEniCS book or FEniCS manual for more
info on
how to set solvers.

Kent

On 17 March 2013 12:51, Peter Franek
<email address hidden>wrote:

> New question #224486 on DOLFIN:
> https://answers.launchpad.net/dolfin/+question/224486
>
> Hello, I installed fenics on windows 7 and tried to run the python
> navier-stokes.demo, but it crashed. This is the message:
> -----------------------------
> Error: Unable to solve linear system using Krylov iteration.
> Reason: Unknownpreconditioner "amg". Use list_krylov_preconditioners() to
> list available preconditioners()
> Where: this error was encountered inside KrylovSlover.cpp.
> -----------------------------
> Any hint what to do? Does it need some other package for those Krylov
> things? Thanks a lot, Peter
>
> --
> You received this question notification because you are a member of
> DOLFIN Team, which is an answer contact for DOLFIN.
>

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