def run(order = 1, static_cond = False,
meshfile = def_meshfile, visualization = False):
mesh = mfem.Mesh(meshfile, 1,1)
dim = mesh.Dimension()
ref_levels = int(np.floor(np.log(10000./mesh.GetNE())/np.log(2.)/dim))
for x in range(ref_levels):
mesh.UniformRefinement();
mesh.ReorientTetMesh();
pmesh = mfem.ParMesh(MPI.COMM_WORLD, mesh)
del mesh
par_ref_levels = 2
for l in range(par_ref_levels):
pmesh.UniformRefinement();
if order > 0:
fec = mfem.H1_FECollection(order, dim)
elif mesh.GetNodes():
fec = mesh.GetNodes().OwnFEC()
prinr( "Using isoparametric FEs: " + str(fec.Name()));
else:
order = 1
fec = mfem.H1_FECollection(order, dim)
fespace =mfem.ParFiniteElementSpace(pmesh, fec)
fe_size = fespace.GlobalTrueVSize()
if (myid == 0):
print('Number of finite element unknowns: '+ str(fe_size))
ess_tdof_list = mfem.intArray()
if pmesh.bdr_attributes.Size()>0:
ess_bdr = mfem.intArray(pmesh.bdr_attributes.Max())
ess_bdr.Assign(1)
fespace.GetEssentialTrueDofs(ess_bdr, ess_tdof_list)
# the basis functions in the finite element fespace.
b = mfem.ParLinearForm(fespace)
one = mfem.ConstantCoefficient(1.0)
b.AddDomainIntegrator(mfem.DomainLFIntegrator(one))
b.Assemble();
x = mfem.ParGridFunction(fespace);
x.Assign(0.0)
a = mfem.ParBilinearForm(fespace);
a.AddDomainIntegrator(mfem.DiffusionIntegrator(one))
if static_cond: a.EnableStaticCondensation()
a.Assemble();
A = mfem.HypreParMatrix()
B = mfem.Vector()
X = mfem.Vector()
a.FormLinearSystem(ess_tdof_list, x, b, A, X, B)
if (myid == 0):
print("Size of linear system: " + str(x.Size()))
print("Size of linear system: " + str(A.GetGlobalNumRows()))
amg = mfem.HypreBoomerAMG(A)
pcg = mfem.HyprePCG(A)
pcg.SetTol(1e-12)
pcg.SetMaxIter(200)
pcg.SetPrintLevel(2)
pcg.SetPreconditioner(amg)
pcg.Mult(B, X);
a.RecoverFEMSolution(X, b, x)
smyid = '{:0>6d}'.format(myid)
mesh_name = "mesh."+smyid
sol_name = "sol."+smyid
pmesh.PrintToFile(mesh_name, 8)
x.SaveToFile(sol_name, 8)
# 16. Project the exact solution to the essential DOFs.
x.ProjectBdrCoefficient(bdr, ess_bdr)
# 17. Create and solve the parallel linear system.
ess_tdof_list = mfem.intArray()
fespace.GetEssentialTrueDofs(ess_bdr, ess_tdof_list)
A = mfem.HypreParMatrix()
B = mfem.Vector()
X = mfem.Vector()
a.FormLinearSystem(ess_tdof_list, x, b, A, X, B)
amg = mfem.HypreBoomerAMG(A)
amg.SetPrintLevel(0)
pcg = mfem.HyprePCG(A)
pcg.SetTol(1e-12)
pcg.SetMaxIter(200)
pcg.SetPrintLevel(0)
pcg.SetPreconditioner(amg)
pcg.Mult(B, X)
# 18. Extract the local solution on each processor.
a.RecoverFEMSolution(X, b, x)
# 19. Send the solution by socket to a GLVis server
if visualization:
sout.send_text("parallel " + str(num_procs) + " " + str(myid))
sout.precision(8)
sout.send_solution(pmesh, x)
def run(order=1,
static_cond=False,
meshfile=def_meshfile,
visualization=False,
use_strumpack=False):
mesh = mfem.Mesh(meshfile, 1, 1)
dim = mesh.Dimension()
ref_levels = int(np.floor(
np.log(10000. / mesh.GetNE()) / np.log(2.) / dim))
for x in range(ref_levels):
mesh.UniformRefinement()
mesh.ReorientTetMesh()
pmesh = mfem.ParMesh(MPI.COMM_WORLD, mesh)
del mesh
par_ref_levels = 2
for l in range(par_ref_levels):
pmesh.UniformRefinement()
if order > 0:
fec = mfem.H1_FECollection(order, dim)
elif mesh.GetNodes():
fec = mesh.GetNodes().OwnFEC()
prinr("Using isoparametric FEs: " + str(fec.Name()))
else:
order = 1
fec = mfem.H1_FECollection(order, dim)
fespace = mfem.ParFiniteElementSpace(pmesh, fec)
fe_size = fespace.GlobalTrueVSize()
if (myid == 0):
print('Number of finite element unknowns: ' + str(fe_size))
ess_tdof_list = mfem.intArray()
if pmesh.bdr_attributes.Size() > 0:
ess_bdr = mfem.intArray(pmesh.bdr_attributes.Max())
ess_bdr.Assign(1)
fespace.GetEssentialTrueDofs(ess_bdr, ess_tdof_list)
# the basis functions in the finite element fespace.
b = mfem.ParLinearForm(fespace)
one = mfem.ConstantCoefficient(1.0)
b.AddDomainIntegrator(mfem.DomainLFIntegrator(one))
b.Assemble()
x = mfem.ParGridFunction(fespace)
x.Assign(0.0)
a = mfem.ParBilinearForm(fespace)
a.AddDomainIntegrator(mfem.DiffusionIntegrator(one))
if static_cond: a.EnableStaticCondensation()
a.Assemble()
A = mfem.HypreParMatrix()
B = mfem.Vector()
X = mfem.Vector()
a.FormLinearSystem(ess_tdof_list, x, b, A, X, B)
if (myid == 0):
print("Size of linear system: " + str(x.Size()))
print("Size of linear system: " + str(A.GetGlobalNumRows()))
if use_strumpack:
import mfem.par.strumpack as strmpk
Arow = strmpk.STRUMPACKRowLocMatrix(A)
args = ["--sp_hss_min_sep_size", "128", "--sp_enable_hss"]
strumpack = strmpk.STRUMPACKSolver(args, MPI.COMM_WORLD)
strumpack.SetPrintFactorStatistics(True)
strumpack.SetPrintSolveStatistics(False)
strumpack.SetKrylovSolver(strmpk.KrylovSolver_DIRECT)
strumpack.SetReorderingStrategy(strmpk.ReorderingStrategy_METIS)
strumpack.SetMC64Job(strmpk.MC64Job_NONE)
# strumpack.SetSymmetricPattern(True)
strumpack.SetOperator(Arow)
strumpack.SetFromCommandLine()
strumpack.Mult(B, X)
else:
amg = mfem.HypreBoomerAMG(A)
pcg = mfem.HyprePCG(A)
pcg.SetTol(1e-12)
pcg.SetMaxIter(200)
pcg.SetPrintLevel(2)
pcg.SetPreconditioner(amg)
pcg.Mult(B, X)
a.RecoverFEMSolution(X, b, x)
smyid = '{:0>6d}'.format(myid)
mesh_name = "mesh." + smyid
sol_name = "sol." + smyid
pmesh.PrintToFile(mesh_name, 8)
x.SaveToFile(sol_name, 8)