# 3. Read the serial mesh from the given mesh file on all processors. We can
# handle triangular, quadrilateral, tetrahedral and hexahedral meshes
# with the same code.
meshfile = expanduser(join(path, 'data', args.mesh))
mesh = mfem.Mesh(meshfile, 1, 1)
dim = mesh.Dimension()
# 4. Define the ODE solver used for time integration. Several implicit
# singly diagonal implicit Runge-Kutta (SDIRK) methods, as well as
# explicit Runge-Kutta methods are available.
if ode_solver_type == 1: ode_solver = BackwardEulerSolver()
elif ode_solver_type == 2: ode_solver = mfem.SDIRK23Solver(2)
elif ode_solver_type == 3: ode_solver = mfem.SDIRK33Solver()
elif ode_solver_type == 11: ode_solver = ForwardEulerSolver()
elif ode_solver_type == 12: ode_solver = mfem.RK2Solver(0.5)
elif ode_solver_type == 13: ode_solver = mfem.RK3SSPSolver()
elif ode_solver_type == 14: ode_solver = mfem.RK4Solver()
elif ode_solver_type == 22: ode_solver = mfem.ImplicitMidpointSolver()
elif ode_solver_type == 23: ode_solver = mfem.SDIRK23Solver()
elif ode_solver_type == 24: ode_solver = mfem.SDIRK34Solver()
else:
print("Unknown ODE solver type: " + str(ode_solver_type))
exit
# 5. Refine the mesh in serial to increase the resolution. In this example
# we do 'ser_ref_levels' of uniform refinement, where 'ser_ref_levels' is
# a command-line parameter.
for lev in range(ser_ref_levels):
mesh.UniformRefinement()
# 6. Define a parallel mesh by a partitioning of the serial mesh. Refine
# 3. Read the serial mesh from the given mesh file on all processors. We can
# handle geometrically periodic meshes in this code.
meshfile = expanduser(join(path, 'data', 'periodic-hexagon.mesh'))
if not exists(meshfile):
path = dirname(dirname(__file__))
meshfile = expanduser(join(path, 'data', 'periodic-hexagon.mesh'))
mesh = mfem.Mesh(meshfile, 1, 1)
dim = mesh.Dimension()
# 4. Define the ODE solver used for time integration. Several explicit
# Runge-Kutta methods are available.
ode_solver = None
if ode_solver_type == 1: ode_solver = mfem.ForwardEulerSolver()
elif ode_solver_type == 2: ode_solver = mfem.RK2Solver(1.0)
elif ode_solver_type == 3: ode_solver = mfem.RK3SSolver()
elif ode_solver_type == 4: ode_solver = mfem.RK4Solver()
elif ode_solver_type == 6: ode_solver = mfem.RK6Solver()
else:
print("Unknown ODE solver type: " + str(ode_solver_type))
exit
# 5. Refine the mesh to increase the resolution. In this example we do
# 'ref_levels' of uniform refinement, where 'ref_levels' is a
# command-line parameter. If the mesh is of NURBS type, we convert it to
# a (piecewise-polynomial) high-order mesh.
for lev in range(ser_ref_levels):
mesh.UniformRefinement()
if mesh.NURBSext:
mesh.SetCurvature(max(order, 1))
def initialize(self, inMeshObj=None, inMeshFile=None):
# 2. Problem initialization
self.parser = ArgParser(description='Based on MFEM Ex16p')
self.parser.add_argument('-m',
'--mesh',
default='beam-tet.mesh',
action='store',
type=str,
help='Mesh file to use.')
self.parser.add_argument('-rs',
'--refine-serial',
action='store',
default=1,
type=int,
help="Number of times to refine the mesh \
uniformly in serial")
self.parser.add_argument('-rp',
'--refine-parallel',
action='store',
default=0,
type=int,
help="Number of times to refine the mesh \
uniformly in parallel")
self.parser.add_argument('-o',
'--order',
action='store',
default=1,
type=int,
help="Finite element order (polynomial \
degree)")
self.parser.add_argument(
'-s',
'--ode-solver',
action='store',
default=3,
type=int,
help='\n'.join([
"ODE solver: 1 - Backward Euler, 2 - SDIRK2, \
3 - SDIRK3", "\t\t 11 - Forward Euler, \
12 - RK2, 13 - RK3 SSP, 14 - RK4."
]))
self.parser.add_argument('-t',
'--t-final',
action='store',
default=20.,
type=float,
help="Final time; start time is 0.")
self.parser.add_argument("-dt",
"--time-step",
action='store',
default=5e-3,
type=float,
help="Time step.")
self.parser.add_argument("-v",
"--viscosity",
action='store',
default=0.00,
type=float,
help="Viscosity coefficient.")
self.parser.add_argument('-L',
'--lmbda',
action='store',
default=1.e0,
type=float,
help='Lambda of Hooks law')
self.parser.add_argument('-mu',
'--shear-modulus',
action='store',
default=1.e0,
type=float,
help='Shear modulus for Hooks law')
self.parser.add_argument('-rho',
'--density',
action='store',
default=1.0,
type=float,
help='mass density')
self.parser.add_argument('-vis',
'--visualization',
action='store_true',
help='Enable GLVis visualization')
self.parser.add_argument('-vs',
'--visualization-steps',
action='store',
default=25,
type=int,
help="Visualize every n-th timestep.")
args = self.parser.parse_args()
self.ser_ref_levels = args.refine_serial
self.par_ref_levels = args.refine_parallel
self.order = args.order
self.dt = args.time_step
self.visc = args.viscosity
self.t_final = args.t_final
self.lmbda = args.lmbda
self.mu = args.shear_modulus
self.rho = args.density
self.visualization = args.visualization
self.ti = 1
self.vis_steps = args.visualization_steps
self.ode_solver_type = args.ode_solver
self.t = 0.0
self.last_step = False
if self.myId == 0: self.parser.print_options(args)
# 3. Reading mesh
if inMeshObj is None:
self.meshFile = inMeshFile
if self.meshFile is None:
self.meshFile = args.mesh
self.mesh = mfem.Mesh(self.meshFile, 1, 1)
else:
self.mesh = inMeshObj
self.dim = self.mesh.Dimension()
print("Mesh dimension: %d" % self.dim)
print("Number of vertices in the mesh: %d " % self.mesh.GetNV())
print("Number of elements in the mesh: %d " % self.mesh.GetNE())
# 4. Define the ODE solver used for time integration.
# Several implicit singly diagonal implicit
# Runge-Kutta (SDIRK) methods, as well as
# explicit Runge-Kutta methods are available.
if self.ode_solver_type == 1:
self.ode_solver = BackwardEulerSolver()
elif self.ode_solver_type == 2:
self.ode_solver = mfem.SDIRK23Solver(2)
elif self.ode_solver_type == 3:
self.ode_solver = mfem.SDIRK33Solver()
elif self.ode_solver_type == 11:
self.ode_solver = ForwardEulerSolver()
elif self.ode_solver_type == 12:
self.ode_solver = mfem.RK2Solver(0.5)
elif self.ode_solver_type == 13:
self.ode_solver = mfem.RK3SSPSolver()
elif self.ode_solver_type == 14:
self.ode_solver = mfem.RK4Solver()
elif self.ode_solver_type == 22:
self.ode_solver = mfem.ImplicitMidpointSolver()
elif self.ode_solver_type == 23:
self.ode_solver = mfem.SDIRK23Solver()
elif self.ode_solver_type == 24:
self.ode_solver = mfem.SDIRK34Solver()
else:
print("Unknown ODE solver type: " + str(self.ode_solver_type))
exit
# 5. Refine the mesh in serial to increase the
# resolution. In this example we do
# 'ser_ref_levels' of uniform refinement, where
# 'ser_ref_levels' is a command-line parameter.
for lev in range(self.ser_ref_levels):
self.mesh.UniformRefinement()
# 6. Define a parallel mesh by a partitioning of
# the serial mesh. Refine this mesh further
# in parallel to increase the resolution. Once the
# parallel mesh is defined, the serial mesh can
# be deleted.
self.pmesh = mfem.ParMesh(MPI.COMM_WORLD, self.mesh)
for lev in range(self.par_ref_levels):
self.pmesh.UniformRefinement()
# 7. Define the vector finite element space
# representing the current and the
# initial temperature, u_ref.
self.fe_coll = mfem.H1_FECollection(self.order, self.dim)
self.fespace = mfem.ParFiniteElementSpace(self.pmesh, self.fe_coll,
self.dim)
self.fe_size = self.fespace.GlobalTrueVSize()
if self.myId == 0:
print("FE Number of unknowns: " + str(self.fe_size))
true_size = self.fespace.TrueVSize()
self.true_offset = mfem.intArray(3)
self.true_offset[0] = 0
self.true_offset[1] = true_size
self.true_offset[2] = 2 * true_size
self.vx = mfem.BlockVector(self.true_offset)
self.v_gf = mfem.ParGridFunction(self.fespace)
self.v_gfbnd = mfem.ParGridFunction(self.fespace)
self.x_gf = mfem.ParGridFunction(self.fespace)
self.x_gfbnd = mfem.ParGridFunction(self.fespace)
self.x_ref = mfem.ParGridFunction(self.fespace)
self.pmesh.GetNodes(self.x_ref)
# 8. Set the initial conditions for u.
#self.velo = InitialVelocity(self.dim)
self.velo = velBCs(self.dim)
#self.deform = InitialDeformation(self.dim)
self.deform = defBCs(self.dim)
self.v_gf.ProjectCoefficient(self.velo)
self.v_gfbnd.ProjectCoefficient(self.velo)
self.x_gf.ProjectCoefficient(self.deform)
self.x_gfbnd.ProjectCoefficient(self.deform)
#self.v_gf.GetTrueDofs(self.vx.GetBlock(0));
#self.x_gf.GetTrueDofs(self.vx.GetBlock(1));
# setup boundary-conditions
self.xess_bdr = mfem.intArray(
self.fespace.GetMesh().bdr_attributes.Max())
self.xess_bdr.Assign(0)
self.xess_bdr[0] = 1
self.xess_bdr[1] = 1
self.xess_tdof_list = intArray()
self.fespace.GetEssentialTrueDofs(self.xess_bdr, self.xess_tdof_list)
#print('True x essential BCs are')
#self.xess_tdof_list.Print()
self.vess_bdr = mfem.intArray(
self.fespace.GetMesh().bdr_attributes.Max())
self.vess_bdr.Assign(0)
self.vess_bdr[0] = 1
self.vess_bdr[1] = 1
self.vess_tdof_list = intArray()
self.fespace.GetEssentialTrueDofs(self.vess_bdr, self.vess_tdof_list)
#print('True v essential BCs are')
#self.vess_tdof_list.Print()
# 9. Initialize the stiffness operator
self.oper = StiffnessOperator(self.fespace, self.lmbda, self.mu,
self.rho, self.visc, self.vess_tdof_list,
self.vess_bdr, self.xess_tdof_list,
self.xess_bdr, self.v_gfbnd,
self.x_gfbnd, self.deform, self.velo,
self.vx)
# 10. Setting up file output
self.smyid = '{:0>2d}'.format(self.myId)
# initializing ode solver
self.ode_solver.Init(self.oper)