# Define coefficient using VecotrPyCoefficient and PyCoefficient
# A user needs to define EvalValue method
#
u0 = InitialCondition(num_equation)
sol = mfem.GridFunction(vfes, u_block.GetData())
sol.ProjectCoefficient(u0)
mesh.PrintToFile("vortex.mesh", 8)
for k in range(num_equation):
uk = mfem.GridFunction(fes, u_block.GetBlock(k).GetData())
sol_name = "vortex-" + str(k) + "-init.gf"
uk.SaveToFile(sol_name, 8)
# 7. Set up the nonlinear form corresponding to the DG discretization of the
# flux divergence, and assemble the corresponding mass matrix.
Aflux = mfem.MixedBilinearForm(dfes, fes)
Aflux.AddDomainIntegrator(DomainIntegrator(dim))
Aflux.Assemble()
A = mfem.NonlinearForm(vfes)
rsolver = RiemannSolver()
ii = FaceIntegrator(rsolver, dim)
A.AddInteriorFaceIntegrator(ii)
# 8. Define the time-dependent evolution operator describing the ODE
# right-hand side, and perform time-integration (looping over the time
# iterations, ti, with a time-step dt).
euler = FE_Evolution(vfes, A, Aflux.SpMat())
if (visualization):
sout = mfem.socketstream("localhost", 19916)
x = mfem.BlockVector(block_offsets) rhs = mfem.BlockVector(block_offsets) fform = mfem.LinearForm() fform.Update(R_space, rhs.GetBlock(0), 0) fform.AddDomainIntegrator(mfem.VectorFEDomainLFIntegrator(fcoeff)) fform.AddBoundaryIntegrator(mfem.VectorFEBoundaryFluxLFIntegrator(fnatcoeff)) fform.Assemble() gform = mfem.LinearForm() gform.Update(W_space, rhs.GetBlock(1), 0) gform.AddDomainIntegrator(mfem.DomainLFIntegrator(gcoeff)) gform.Assemble() mVarf = mfem.BilinearForm(R_space) bVarf = mfem.MixedBilinearForm(R_space, W_space) mVarf.AddDomainIntegrator(mfem.VectorFEMassIntegrator(k)) mVarf.Assemble() mVarf.Finalize() M = mVarf.SpMat() bVarf.AddDomainIntegrator(mfem.VectorFEDivergenceIntegrator()) bVarf.Assemble() bVarf.Finalize() B = bVarf.SpMat() B *= -1 BT = mfem.Transpose(B) darcyOp = mfem.BlockOperator(block_offsets) darcyOp.SetBlock(0, 0, M)
# 6. Set up the linear form F(.) which corresponds to the right-hand side of # the FEM linear system, which in this case is (f,phi_i) where f=1.0 and # phi_i are the basis functions in the test finite element fespace. one = mfem.ConstantCoefficient(1.0) F = mfem.LinearForm(test_space); F.AddDomainIntegrator(mfem.DomainLFIntegrator(one)) F.Assemble(); # 7. Set up the mixed bilinear form for the primal trial unknowns, B0, # the mixed bilinear form for the interfacial unknowns, Bhat, # the inverse stiffness matrix on the discontinuous test space, Sinv, # and the stiffness matrix on the continuous trial space, S0. ess_bdr = mfem.intArray(mesh.bdr_attributes.Max()) ess_bdr.Assign(1) B0 = mfem.MixedBilinearForm(x0_space,test_space); B0.AddDomainIntegrator(mfem.DiffusionIntegrator(one)) B0.Assemble() B0.EliminateTrialDofs(ess_bdr, x.GetBlock(x0_var), F) B0.Finalize() Bhat = mfem.MixedBilinearForm(xhat_space,test_space) Bhat.AddTraceFaceIntegrator(mfem.TraceJumpIntegrator()) Bhat.Assemble() Bhat.Finalize() Sinv = mfem.BilinearForm(test_space) Sum = mfem.SumIntegrator() Sum.AddIntegrator(mfem.DiffusionIntegrator(one)) Sum.AddIntegrator(mfem.MassIntegrator(one)) Sinv.AddDomainIntegrator(mfem.InverseIntegrator(Sum))