Re: [Libmesh-devel] FE::inverse_map() not converging...

[Roy S. <roy...@ic...>]

On Wed, 21 Jun 2006, Derek Gaston wrote:

> what I get:
>
> WARNING: Newton scheme has not converged in 31 iterations:
>  physical_point=(x,y,z)=(0.158938, 0.422823,        0)
>  physical_guess=(x,y,z)=(0.497654,  0.17708,        0)
>  dp=(x,y,z)=(-9.77611,  7.05057,        0)
>  p=(x,y,z)=(0.685321, 0.746925,        0)
> secure=1   error=12.0533
>
> How in the _HELL_ is secure=1?!???!???!?!!

Keep in mind that secure==true is the default argument, and
inverse_map gets called from more than just the point locator.  Even
when you're not using adaptivity, your code may be calling inverse_map
from FE::nodal_soln, FE::edge_reinit, or MeshFunction::operator().
However, none of those functions should ever give you an inverse_map
that doesn't converge, so it's important that we find what's wrong.

At the very least, it would be a good idea to print out the node
locations of the element for which inverse_map is failing.  If the
physical point is inside the element and the element has a positive
lower bound on it's jacobian, then we'll know it's a serious problem
and we'll probably have enough information to replicate it.
---
Roy