Hello,
Upon running the following code, using dsf1 or dsf2, I get a matrix of zeroes. However, I am anticipating a non-zero matrix. What can be causing the error?
from ngsolve import *
from netgen.geom2d import SplineGeometry
ngsglobals.msg_level=1
def topBottom():
geometry = SplineGeometry()
pnts = [ (0, 0), (0.5, 0), (1, 0), (1, 1), (0.5, 1), (0, 1) ]
pnums = [geometry.AppendPoint(*p) for p in pnts]
lines = [ (pnums[0], pnums[1], "gamma1", 1, 0),
(pnums[1], pnums[2], "gamma2", 2, 0),
(pnums[2], pnums[3], "gamma2", 2, 0),
(pnums[3], pnums[4], "gamma2", 2, 0),
(pnums[4], pnums[5], "gamma1", 1, 0),
(pnums[5], pnums[0], "gamma1", 1, 0),
(pnums[1], pnums[4], "gammaf", 1, 2)]
for p1,p2,bc,left, right in lines:
geometry.Append( ["line", p1, p2], bc=bc, leftdomain=left, rightdomain=right)
geometry.SetMaterial(1, "Domain1")
geometry.SetMaterial(2, "Domain2")
return geometry
mesh = Mesh(topBottom().GenerateMesh (maxh=0.1))
n = specialcf.normal(mesh.dim)
V = VectorL2(mesh, order=1, dgjumps=True)
Q = H1(mesh, order=1, definedon=mesh.Boundaries("gammaf"), dirichlet="gamma1|gamma2")
X=FESpace([V,Q])
(u,p),(v,q)=X.TnT()
dsf1=dx(element_boundary=True,definedon=mesh.Boundaries("gammaf"))
dsf2=dx(skeleton=True,definedon=mesh.Boundaries("gammaf"))
a=BilinearForm(X,check_unused=False)
a+=(p*(v-v.Other())*n+q*(u-u.Other())*n)*dsf2
_,_,vals = a.Assemble().mat.COO()
npvals = vals.NumPy()
print('assemble values = ', (npvals*npvals).sum())
