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

2014-08-07 Thread David Knezevic
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 li

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

2014-07-16 Thread Derek Gaston
I would find a bit more fuzziness here to be useful myself Derek On Tue, Jul 15, 2014 at 8:53 PM, David Knezevic 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

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

2014-07-15 Thread David Knezevic
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 preve

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

2014-07-15 Thread Roy Stogner
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 pertur

Re: [Libmesh-users] MeshFunction

2013-05-24 Thread Manav Bhatia
I tried running in the debug mode (should have done that earlier) and the code aborted with the following error. No index 128 in ghosted vector. Vector contains [1352,2604) And empty ghost array. [1] ./include/libmesh/petsc_vector.h, line 1176, compiled May 22 2013 at 22:27:31 It also was tr

Re: [Libmesh-users] MeshFunction

2013-05-24 Thread Kirk, Benjamin (JSC-EG311)
Put another way, solution contains storage for remote entries but it cannot keep them in sync under all usage cases (1) for performance reasons and (2) to avoid parallel deadlocks. So depending on when you are accessing it the remote values may be stale, leading to chaos. -Ben On May 24,

Re: [Libmesh-users] MeshFunction

2013-05-24 Thread Derek Gaston
What are you trying to do? There are many scenarios where this could fail... and some where it might succeed. Derek Sent from my iPad On May 24, 2013, at 8:02 AM, Manav Bhatia wrote: > > > On May 24, 2013, at 9:58 AM, Derek Gaston wrote: > >> Yes. >> >> Ok, well, MeshFunction itself doesn't

Re: [Libmesh-users] MeshFunction

2013-05-24 Thread Manav Bhatia
On May 24, 2013, at 9:58 AM, Derek Gaston wrote: > Yes. > > Ok, well, MeshFunction itself doesn't care (as you found out)... but > if you want to evaluate your solution in elements containing > off-processor degrees of freedom then you need to serialize that > vector. > But if the element i

Re: [Libmesh-users] MeshFunction

2013-05-24 Thread Derek Gaston
Yes. Ok, well, MeshFunction itself doesn't care (as you found out)... but if you want to evaluate your solution in elements containing off-processor degrees of freedom then you need to serialize that vector. Think of it this way: MeshFunction doesn't do parallel communication... you are responsib

Re: [Libmesh-users] Meshfunction::gradient()

2012-12-06 Thread Roy Stogner
On Thu, 6 Dec 2012, Ataollah Mesgarnejad wrote: > I was wondering if there is any reasons for MeshFunction::gradient not to > work with C1 (Clough) elements? In theory, it should work fine. If anything I'd expect it to work *better* for C1 elements, since the results would always be well-defin

Re: [Libmesh-users] MeshFunction

2009-01-12 Thread Tim Kroeger
Dear Roy, On Mon, 12 Jan 2009, Roy Stogner wrote: > On Mon, 12 Jan 2009, Tim Kroeger wrote: > >> At the end of my application, I want to evaluate the computed solution >> at a number of points (which cannot be assumed to be grid nodes). >> Since I only want to write the values to a file, it suffi

Re: [Libmesh-users] MeshFunction

2009-01-12 Thread Roy Stogner
On Mon, 12 Jan 2009, Derek Gaston wrote: > On Jan 12, 2009, at 10:05 AM, Roy Stogner wrote: > >> Really, what we need is to properly parallelize MeshFunction, but I'm >> not sure what the right API is to do that with MPI. If processor A >> wants to evaluate the function on a point in processor B

Re: [Libmesh-users] MeshFunction

2009-01-12 Thread Derek Gaston
On Jan 12, 2009, at 10:05 AM, Roy Stogner wrote: > Really, what we need is to properly parallelize MeshFunction, but I'm > not sure what the right API is to do that with MPI. If processor A > wants to evaluate the function on a point in processor B's elements, > processor B (which probably has a

Re: [Libmesh-users] MeshFunction

2009-01-12 Thread Roy Stogner
On Mon, 12 Jan 2009, Tim Kroeger wrote: > At the end of my application, I want to evaluate the computed solution > at a number of points (which cannot be assumed to be grid nodes). > Since I only want to write the values to a file, it suffices to do > this on one processor. > > My idea was: > > 1