Chladni figures Barycentric refinement

Here are some Chladni figures of of the Barycentric refinement G3 of the triangle K3. This graph has 121 vertices. The level surfaces are in the refinement G4 shown here. We want to understand the spectral gaps, the discontinuities of the spectral functions F. Like the gap occurring at x=1/2, which corresponds to the change from eigenvalue number 60 to number 61. See the preprint "The graph spectrum of barycentric refinements" for the math and mini blog, Same pictures for G3, a polyhedron or or a square.