simple.form

finite element library for mathematic majored research

DG1 = FiniteElement("Discontinuous Lagrange", "triangle", 1)

v = TestFunction(DG1)
u = TrialFunction(DG1)

n = FacetNormal("triangle")

def Jump(v):
    return [v*n[i] for i in range(2)]

#a = v('+')*u('-')*dS + dot(jump(v,n), jump(u,n))*ds
a = v('+')*u('-')*dS + dot(Jump(v), Jump(u))*ds
print a