Re: [Libmesh-users] MeshFunction for point slightly outside mesh

[David K. <dkn...@se...>]

I made a pull request related to this.

If the PointLocatorTree doesn't find the element, I use a linear search 
over the mesh with Elem::close_to_point as a back-up. It works well for 
me. It's slower than the tree, of course, but it's only a back-up so 
seems fine to me. Also, we already had a linear search as a back-up in 
PointLocatorTree.

Let me know if it looks OK to you.

David




On 07/16/2014 05:43 PM, Derek Gaston wrote:
> I would find a bit more fuzziness here to be useful myself....
>
>
> Derek
>
>
> On Tue, Jul 15, 2014 at 8:53 PM, David Knezevic 
> <dkn...@se... <mailto:dkn...@se...>> wrote:
>
>
>     On 07/15/2014 10:51 PM, Roy Stogner wrote:
>     >
>     > On Tue, 15 Jul 2014, David Knezevic wrote:
>     >
>     >> I use MeshFunction a lot, it's very helpful. But sometimes due to
>     >> rounding error, I evaluate a MeshFunction at a point just
>     outside the
>     >> mesh, and hence the evaluation fails.
>     >>
>     >> I'd like to prevent this type of failure.
>     >>
>     >> I was thinking of perturbing the evaluation point in various
>     directions
>     >> (p + (delta,0,0), p + (0,delta,0), etc) until I find a point
>     that is
>     >> inside the mesh. This seems like it would work, but it's not very
>     >> elegant. I was wondering if anyone has any other ideas about
>     how to go
>     >> about this?
>     >
>     > We currently use Elem::contains_point() with default tolerance
>     in the
>     > point_locator in MeshFunction.  Perhaps we could switch that to
>     > Elem::close_to_point(), add functionality to the point locators to
>     > allow increasing the tolerance, and expose that in the MeshFunction?
>
>     That sounds very good to me.
>
>     David
>
>
>     ------------------------------------------------------------------------------
>     Want fast and easy access to all the code in your enterprise?
>     Index and
>     search up to 200,000 lines of code with a free copy of Black Duck
>     Code Sight - the same software that powers the world's largest code
>     search on Ohloh, the Black Duck Open Hub! Try it now.
>     http://p.sf.net/sfu/bds
>     _______________________________________________
>     Libmesh-users mailing list
>     Lib...@li...
>     <mailto:Lib...@li...>
>     https://lists.sourceforge.net/lists/listinfo/libmesh-users
>
>