On Mon, Jul 18, 2016 at 12:13 PM, Roy Stogner <royst...@ices.utexas.edu> wrote:
> > On Mon, 18 Jul 2016, Xujun Zhao wrote: > > Yes, the points are not quad-points but arbitrary points, which are moving >> particles in the domain. It mainly happened when the points are out of the >> element. >> > > Oh, yes, looking for points far outside an element can give you > inverse map failures. If you imagine extending the master->physical > element map for, say, a QUAD4 trapezoid with one very narrow side on > top, you can see how the map stops being invertible a little way above > that top. We avoid ever hitting many such cases because we precede > the inverse_map with a bounding box test, but that's a performance > optimization, not a guarantee of an invertible map. We pass > secure=false to inverse_map to, in theory, avoid screaming and dying > when handling a case that might be expected to fail. > > Looks like there's a bug in the 3D case, though? We rely on > TypeTensor::solve() in the Newton iteration in 3D, but we *don't* warn > solve() (or have a way to warn solve()?) that in the secure=false case > we don't necessarily expect a solution to exist. > I can fix this. The zero determinant asserts could be changed to libmesh_error()'s (or explicit exception throws) and then we could catch the exception in inverse_map(). It should be an "exceptional" case, so it seems reasonable to me. Other options would be to return an error code, or pass an extra flag to TypeTensor::solve()? In these cases you'd have to check the flag every time... -- John ------------------------------------------------------------------------------ What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports.http://sdm.link/zohodev2dev _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
