Dear developers of Elmer,

We consider using your library. We intend to make a custom solver related to your microwave examples, (link below). Thus, we are not making a standard problem but rather our own, and here we need to extract relevant element matrices and some surface integration. In more detail,

Is there any example where we can see the generation of the stiffness part (precisely curl N_i - curl N_j) and the mass part (N_i N_j), where N_i are edge basis functions?

Second, for the evaluation of general surface integrals, we also need integration rules on faces for given edge elements. Are there any such examples?

https://github.com/ElmerCSC/elmer-elmag ... aveHeating

Looking forward to your feedback.

Thanks, Batra

## Edge Element Matrices / Microwave Examples

### Re: Edge Element Matrices / Microwave Examples

A rather simple example of coding a solver which uses H(curl)-conforming finite elements could be

https://github.com/ElmerCSC/elmerfem/bl ... onTest.F90

In a special case (Material Param = Real 0.0) it assembles just the mass matrix. However, it doesn't perform assembly over lower-dimensional boundary elements. A simple example of generating an assembly loop over the boundary elements may be missing, but you could probably check for example the subroutine LocalMatrixBC in the file

https://github.com/ElmerCSC/elmerfem/bl ... Solver.F90

The most relevant file related to this case would however be

https://github.com/ElmerCSC/elmerfem/bl ... mholtz.F90

which is not so simple anymore.

https://github.com/ElmerCSC/elmerfem/bl ... onTest.F90

In a special case (Material Param = Real 0.0) it assembles just the mass matrix. However, it doesn't perform assembly over lower-dimensional boundary elements. A simple example of generating an assembly loop over the boundary elements may be missing, but you could probably check for example the subroutine LocalMatrixBC in the file

https://github.com/ElmerCSC/elmerfem/bl ... Solver.F90

The most relevant file related to this case would however be

https://github.com/ElmerCSC/elmerfem/bl ... mholtz.F90

which is not so simple anymore.

### Re: Edge Element Matrices / Microwave Examples

Indeed, the last example does solve the bulk terms. We now go over your boundary suggestions.

Thanks, K Batra

Thanks, K Batra