complex-valued problem in XFEM

Hi Shaoqi,

code like is used to mark element boundaries (facets) based on elements cut by the level set in the entire mesh for ghost-penalty stabilisation, which is then done over the entire marked facet.

Best wishes,
Henry

As a side note: If all you need is to define integrators on fixed parts of the boundary, another solution would be to define the split in the geometry, so that this is discretised by the mesh.

Many thanks! Yes, that could be a solution, but kind of manually.
Cause we have a geometry cut by the interface defined with the level set, it is better we can get the boundaries' info of the "new" geometry directly.
In other words, the geometry could be split automatically once we create the levelset domain.