Hi,

I am trying to apply explicit residual method, and I need to integrate error estimates elementwise on Neumann and Robin boundaries. I encounter similar problem as https://forum.ngsolve.org/t/local-edge-estimator-separately-defined-on-neumann-boundaries-and-interfaces/1600

The only difference is that here as an optional input for dx() I add a

element_vb = BND

But still, we have nonzero entries for some elements with edges that are not labeled as ‘Neumann’ boundaries.

Is there any right way to do this elementwise integration on the labeled boundary edges only?

Thanks in advance for any possible help.