3D benchmarks

[fdrmrc]

Piston

• Solution $\Pi_{i=1}^3 \sin(\pi \frac{x_i}{f})$, with $f = 10$ scaling factor.
• Number of background hexahedral elements 45714
• Number of agglomerated polytopes: 1600

Some preliminary results with METIS. (@andreacangiani @luca-heltai it was indeed a matter of scaling... )

[fdrmrc]

Here something peraphs more interesting, where also the R-tree approach is used. The polytopic grid is made by 731 elements:

In $L^2$ METIS performs slightly better in this case, but I'd say that both results are definitely comparable in terms of accuracy.