[CIG-MC] Problems running a .prm file

[Wolfgang Bangerth]

Timothy,

> tknelson at ymir:~/BoxDimen$ more sbdimebox-2234-c12-7.output
> Module gmt/5.1.1 loaded
> -----------------------------------------------------------------------------
> -- This is ASPECT, the Advanced Solver for Problems in Earth's ConvecTion.
> --     . version 1.2.pre
> --     . running in OPTIMIZED mode

What happens if you run this in debug mode, and maybe with a smaller problem?


> --------------------------------------------------------
> An error occurred in line <424> of file
> </home/tknelson/.hashdist/tmp/aspect-vhqwqb464ta
> d/source/simulator/solver.cc> in function
>      double aspect::Simulator<dim>::solve_advection(const
> aspect::Simulator<dim>::Advecti
> onField&) [with int dim = 2]
> The violated condition was:
>      false
> The name and call sequence of the exception was:
>      ExcMessage (std::string("The iterative advection solver " "did not
> converge. It repo
> rted the following error:\n\n") + exc.what())
> Additional Information:
> The iterative advection solver did not converge. It reported the following error:
>
>
> --------------------------------------------------------
> An error occurred in line <828> of file
> </home/tknelson/.hashdist/bld/dealii/lrx5yq7iora
> t/include/deal.II/lac/solver_gmres.h> in function
>      void dealii::SolverGMRES<VECTOR>::solve(const MATRIX&, VECTOR&, const
> VECTOR&, const
>   PRECONDITIONER&) [with MATRIX = dealii::TrilinosWrappers::SparseMatrix;
> PRECONDITIONER
> = dealii::TrilinosWrappers::PreconditionILU; VECTOR =
> dealii::TrilinosWrappers::MPI::Vec
> tor]
> The violated condition was:
>      false
> The name and call sequence of the exception was:
>      SolverControl::NoConvergence (this->control().last_step(),
> this->control().last_valu
> e())
> Additional Information:
> Iterative method reported convergence failure in step 1000 with residual
> 2.76979e+14

This may indicate that your problem is very ill-conditioned or ill posed, for 
example because you have negative densities or negative thermal conduction 
coefficients. In essence, 1000 GMRES iterations appear to simply not be enough 
to solve the problem, but it's unclear to me whether that means that a larger 
number than that would actually make the method converge, or whether the 
problem is truly ill posed.

The way to find out is to start with debug mode and smaller problem sizes.

Best
  W.

-- 
------------------------------------------------------------------------
Wolfgang Bangerth               email:            bangerth at math.tamu.edu
                                 www: http://www.math.tamu.edu/~bangerth/