fem.select_faces

fem.select_faces(mesh, predicate)

Select boundary faces whose center (and normal) satisfy a predicate.

Works on either element family: the mesh only has to expose all_boundary_faces().

Parameters

Name	Type	Description	Default
mesh	HexMesh | TetMesh	The volume mesh.	required
predicate	Callable[…, Any]	Called per face as predicate(center) or predicate(center, normal) (arity is inspected); truthy return keeps the face.	required

Returns

Name	Type	Description
A	FaceGroup	class:FaceGroup of the matching faces.