Re: [Libmesh-users] Trouble with boundary integration

>Any hint on how to easily reproduce the shape function calculations by hand >(that is, manually producing the dphi_face values)? Very carefully :) I ended up writing some polynomial classes and doing the integrals and derivatives for QUAD4 that way. With my rational number class it was easy to

Re: [Libmesh-users] Trouble with boundary integration

On Fri, Aug 25, 2017 at 7:19 PM, John Peterson wrote: > > > On Fri, Aug 25, 2017 at 1:02 PM, Renato Poli wrote: > >> Hi John, >> >> I am still struggling and running out of ideas here. >> > > Are you using FIRST and SECOND, LAGRANGE variables? If so, are

Re: [Libmesh-users] Trouble with boundary integration

I've been trying to learn this myself and encounter a variety of issues like this. If you have an exact solution, why not just print all the pieces- values and normals etc- and see how they differ point by point instead of trying to do an inverse problem of guessing what is wrong with an

Re: [Libmesh-users] Trouble with boundary integration

Hi John, I am still struggling and running out of ideas here. I wrote down some debugging - perhaps you can find something weird. The calculations seem correct, at least to what I could understand so far. But things are zero'ing out. If, in the mesh creation, I declare the variable as "FIRST"

Re: [Libmesh-users] Trouble with boundary integration

Hi John, _sys_solution is the system->solution vector. It is fed by: _system.solution->localize_to_one( _sys_solution ); On Fri, Aug 25, 2017 at 1:48 PM, John Peterson wrote: > > > On Fri, Aug 25, 2017 at 10:34 AM, Renato Poli wrote: > >> Hi,

Re: [Libmesh-users] Trouble with boundary integration

On Fri, Aug 25, 2017 at 10:34 AM, Renato Poli wrote: > Hi, > > I need some help here ... > > I am having trouble to understand what is going on with a boundary > integral. > I have solved a Poisson problem for pressure in a 2D mesh, as a model for a > incompressible water flow

[Libmesh-users] Trouble with boundary integration

Hi, I need some help here ... I am having trouble to understand what is going on with a boundary integral. I have solved a Poisson problem for pressure in a 2D mesh, as a model for a incompressible water flow in porous media. The mesh (Tri6 elements) has a near-circular polygon in the middle