I am trying to define UFL to use in the variational formulation.
PM = FunctionSpace(mesh, ‘DG’, 0)
TM = TensorFunctionSpace(mesh, ‘DG’, 0)
u = Function(U)
phi0 = Function(PM)
k0 = Function™
perm_min = 1e-20
perm_min_tensor = Constant(((perm_min, 0.), (0., perm_min)))
k = k0*pow(1.0+vs/phi0,3.0)/(1.0+vs)
The idea is to use this perm_newton in the variational formulation to solve the non-linear problem. Since pow(1.0+vs/phi0,3.0)/(1.0+vs) can be negative, perm_min_tensor is built to prevent perm_newton(vol_strain(u),phi0,k0) becomes less than zero. However, ‘ge(a,b)’ requires ‘ufl.log.UFLException: Expecting scalar arguments.’. Does anyone have any recommendations?