def __init__(self, spaces, mass, offsets):
self.pressure_mass = mass
self.block_offsets = offsets
super(JacobianPreconditioner, self).__init__(offsets[2])
self.gamma = 0.00001
# The mass matrix and preconditioner do not change every Newton cycle, so we
# only need to define them once
self.mass_prec = mfem.GSSmoother(mass)
mass_pcg = mfem.CGSolver()
mass_pcg.SetRelTol(1e-12)
mass_pcg.SetAbsTol(1e-12)
mass_pcg.SetMaxIter(200)
mass_pcg.SetPrintLevel(0)
mass_pcg.SetPreconditioner(self.mass_prec)
mass_pcg.SetOperator(self.pressure_mass)
mass_pcg.iterative_mode = False
self.mass_pcg = mass_pcg
# The stiffness matrix does change every Newton cycle, so we will define it
# during SetOperator
self.stiff_pcg = None
self.stiff_prec = None
def __init__(self, fespace, alpha, kappa, u):
mfem.PyTimeDependentOperator.__init__(self, fespace.GetTrueVSize(),
0.0)
rel_tol = 1e-8
self.alpha = alpha
self.kappa = kappa
self.T = None
self.K = None
self.M = None
self.fespace = fespace
self.ess_tdof_list = intArray()
self.Mmat = mfem.SparseMatrix()
self.Kmat = mfem.SparseMatrix()
self.M_solver = mfem.CGSolver()
self.M_prec = mfem.DSmoother()
self.T_solver = mfem.CGSolver()
self.T_prec = mfem.DSmoother()
self.z = mfem.Vector(self.Height())
self.M = mfem.BilinearForm(fespace)
self.M.AddDomainIntegrator(mfem.MassIntegrator())
self.M.Assemble()
self.M.FormSystemMatrix(self.ess_tdof_list, self.Mmat)
self.M_solver.iterative_mode = False
self.M_solver.SetRelTol(rel_tol)
self.M_solver.SetAbsTol(0.0)
self.M_solver.SetMaxIter(30)
self.M_solver.SetPrintLevel(0)
self.M_solver.SetPreconditioner(self.M_prec)
self.M_solver.SetOperator(self.Mmat)
self.T_solver.iterative_mode = False
self.T_solver.SetRelTol(rel_tol)
self.T_solver.SetAbsTol(0.0)
self.T_solver.SetMaxIter(100)
self.T_solver.SetPrintLevel(0)
self.T_solver.SetPreconditioner(self.T_prec)
self.SetParameters(u)
def __init__(self, M, K, b):
mfem.PyTimeDependentOperator.__init__(self, M.Size())
self.K = K
self.M = M
self.b = b
self.z = mfem.Vector(M.Size())
self.zp = np.zeros(M.Size())
self.M_prec = mfem.DSmoother()
self.M_solver = mfem.CGSolver()
self.M_solver.SetPreconditioner(self.M_prec)
self.M_solver.SetOperator(M)
self.M_solver.iterative_mode = False
self.M_solver.SetRelTol(1e-9)
self.M_solver.SetAbsTol(0.0)
self.M_solver.SetMaxIter(100)
self.M_solver.SetPrintLevel(0)
def __init__(self, fespace, ess_bdr, visc, mu, K):
mfem.PyTimeDependentOperator.__init__(self, 2 * fespace.GetVSize(),
0.0)
rel_tol = 1e-8
skip_zero_entries = 0
ref_density = 1.0
self.z = mfem.Vector(self.Height() / 2)
self.fespace = fespace
self.viscosity = visc
M = mfem.BilinearForm(fespace)
S = mfem.BilinearForm(fespace)
H = mfem.NonlinearForm(fespace)
self.M = M
self.H = H
self.S = S
rho = mfem.ConstantCoefficient(ref_density)
M.AddDomainIntegrator(mfem.VectorMassIntegrator(rho))
M.Assemble(skip_zero_entries)
M.EliminateEssentialBC(ess_bdr)
M.Finalize(skip_zero_entries)
M_solver = mfem.CGSolver()
M_prec = mfem.DSmoother()
M_solver.iterative_mode = False
M_solver.SetRelTol(rel_tol)
M_solver.SetAbsTol(0.0)
M_solver.SetMaxIter(30)
M_solver.SetPrintLevel(0)
M_solver.SetPreconditioner(M_prec)
M_solver.SetOperator(M.SpMat())
self.M_solver = M_solver
self.M_prec = M_prec
model = mfem.NeoHookeanModel(mu, K)
H.AddDomainIntegrator(mfem.HyperelasticNLFIntegrator(model))
H.SetEssentialBC(ess_bdr)
self.model = model
visc_coeff = mfem.ConstantCoefficient(visc)
S.AddDomainIntegrator(mfem.VectorDiffusionIntegrator(visc_coeff))
S.Assemble(skip_zero_entries)
S.EliminateEssentialBC(ess_bdr)
S.Finalize(skip_zero_entries)
self.backward_euler_oper = BackwardEulerOperator(M, S, H)
J_prec = mfem.DSmoother(1)
J_minres = mfem.MINRESSolver()
J_minres.SetRelTol(rel_tol)
J_minres.SetAbsTol(0.0)
J_minres.SetMaxIter(300)
J_minres.SetPrintLevel(-1)
J_minres.SetPreconditioner(J_prec)
self.J_solver = J_minres
self.J_prec = J_prec
newton_solver = mfem.NewtonSolver()
newton_solver.iterative_mode = False
newton_solver.SetSolver(self.J_solver)
newton_solver.SetOperator(self.backward_euler_oper)
newton_solver.SetPrintLevel(1)
#print Newton iterations
newton_solver.SetRelTol(rel_tol)
newton_solver.SetAbsTol(0.0)
newton_solver.SetMaxIter(10)
self.newton_solver = newton_solver
# 9. Set up a block-diagonal preconditioner for the 2x2 normal equation
#
# [ S0^{-1} 0 ]
# [ 0 Shat^{-1} ] Shat = (Bhat^T Sinv Bhat)
#
# corresponding to the primal (x0) and interfacial (xhat) unknowns.
# RAP_R replaces RAP, since RAP has two definition one accept
# pointer and the other accept reference. From Python, two
# can not be distingished..
Shat = mfem.RAP_R(matBhat, matSinv, matBhat);
prec_rtol = 1e-3
prec_maxit = 200
S0inv = mfem.CGSolver()
S0inv.SetOperator(matS0)
S0inv.SetPrintLevel(-1)
S0inv.SetRelTol(prec_rtol)
S0inv.SetMaxIter(prec_maxit)
Shatinv = mfem.CGSolver()
Shatinv.SetOperator(Shat)
Shatinv.SetPrintLevel(-1)
Shatinv.SetRelTol(prec_rtol)
Shatinv.SetMaxIter(prec_maxit)
# Disable 'iterative_mode' when using CGSolver (or any IterativeSolver) as
# a preconditioner:
S0inv.iterative_mode = False
Shatinv.iterative_mode = False
