Hendrik Ranocha

These weights should be the entries on the diagonal of the SBP mass/norm matrix `M`.

Sure, would be great :+1:

I think I should have implemented everything in terms of `mul!`, e.g., https://github.com/ranocha/SummationByPartsOperators.jl/blob/4854524c5c8152a6cd640b3bcf683f81cb4d7d8b/src/coupling.jl#L424-L439 If that doesn't work, please let me know! PRs are always welcome, of course.

Ah, I see. Yeah, the case of 5-arg `mul!` is more complicated for this case. The CGSEM operators are easier to write down at the level of `M * D`,...

See also https://arxiv.org/abs/2405.08770 (An optimization-based construction procedure for function space based summation-by-parts operators on arbitrary grids)

There is some code online at https://github.com/phioeffn/SBP-Construction. However, it doesn't have a license, so we cannot do anything with it (and should avoid looking at it at all...)

Currently, dissipation operators are only implemented for - `MattssonSvärdNordström2004` (see `SummationByPartsOperators.dissipation_coefficients`) - `PeriodicDerivativeOperator`s (taking basically the interior parts of the operators of `MattssonSvärdNordström2004`) - `FourierDerivativeOperator`s Adding the dissipation operators of...

Interesting idea, thanks!

Coefficients available at https://github.com/VidarStiernstrom/bopt_sbp_ops

Orders 2, 4, and 6 are implemented in 77d5e1393c74ea3257e98ccc4fa8c7624039ea94. The first attempt to implement the order 8 seems to be erroneous.