Dear getfem users.
I am new to getfem and trying to understand "demo_fictitious_domains.py" included in the source code package. And I am having a trouble understanding how boundary integrals work.
As far as I could tell, since the spatial dimension is 2 in this example, the boundary defined by zero levelset consists only of lines.
However, the code in line 94 says that the integration points on a triangle are used,
mim_bound = gf.MeshIm('levelset',mls,'boundary(a+b)', gf.Integ('IM_TRIANGLE(6)'))
and
gf.Integ('IM_TRIANGLE(6)') is in python
gfInteg object IM_TRIANGLE(6)Cubature method in dimension 2 with 12 Gauss points
So, I am confused here. How does this relate to boundary (line) integral?
Thank you in advance.