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greedy.py
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Sat, May 4, 19:38

greedy.py
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import numpy as np
import fenics as fen
import ufl
from rrompy.hfengines.vector_linear_problem import \
LinearElasticityHelmholtzProblemEngine as LEHPE
from rrompy.hfengines.vector_linear_problem import \
LinearElasticityHelmholtzProblemEngineDamped as LEHPED
from rrompy.reduction_methods.distributed_greedy import \
RationalInterpolantGreedy as Pade
from rrompy.reduction_methods.distributed_greedy import \
RBDistributedGreedy as RB
from rrompy.solver.fenics import L2NormMatrix
verb = 2
timed = False
algo = "Pade"
#algo = "RB"
polyBasis = "LEGENDRE"
polyBasis = "CHEBYSHEV"
#polyBasis = "MONOMIAL"
if timed: verb = 0
dampingEta = 0 * 1e4 / 2. / np.pi
k0s = np.linspace(2.5e2, 7.5e3, 100)
k0s = np.linspace(2.5e3, 1.5e4, 100)
k0s = np.linspace(5.0e4, 1.0e5, 100)
k0s = np.linspace(2.0e5, 2.5e5, 100)
k0 = np.mean(np.power(k0s, 2.)) ** .5 # [Hz]
kl, kr = min(k0s), max(k0s)
params = {'muBounds':[kl, kr], 'nTestPoints':500, 'Delta':0,
'greedyTol':1e-2, 'S':2, 'polybasis':polyBasis,
'robustTol':2e-16, 'interpRcond':None, 'errorEstimatorKind':'EXACT'}
theta = 20. * np.pi / 180.
phi = 10. * np.pi / 180.
mesh = fen.Mesh("../data/mesh/diapason_1.xml")
subdomains = fen.MeshFunction("size_t", mesh,
"../data/mesh/diapason_1_physical_region.xml")
meshBall = fen.SubMesh(mesh, subdomains, 2)
meshFork = fen.SubMesh(mesh, subdomains, 1)
Hball = np.max(meshBall.coordinates()[:, 1]) #.00257
Ltot = np.max(mesh.coordinates()[:, 1]) #.1022
Lhandle = np.max(meshFork.coordinates()[:, 1]) #.026
Lrod = Ltot - Lhandle #.0762
L2var = (Lrod / 4.) ** 2.
Ehandle_ratio = 3.
rhohandle_ratio = 1.5
c = 3.e2
rho = 8e3 * (2. * np.pi) ** 2.
E = 1.93e11
nu = .3
T = 1e6
lambda_ = E * nu / (1. + nu) / (1. - 2. * nu)
mu_ = E / (1. + nu)
kWave = (np.cos(theta) * np.cos(phi), np.sin(phi), np.sin(theta) * np.cos(phi))
x, y, z = fen.SpatialCoordinate(mesh)[:]
yCorr = y - Ltot
compPlane = kWave[0] * x + kWave[1] * y + kWave[2] * z
xPlane, yPlane, zPlane = (xx - compPlane * xx for xx in (x, y, z))
xOrtho, yOrtho, zOrtho = (compPlane * xx for xx in (x, y, z))
forcingBase = (T / (2. * np.pi * L2var)**.5
* fen.exp(- (xPlane**2. + yPlane**2. + zPlane**2.) / (2.*L2var)))
forcingWeight = np.real(k0) / c * (xOrtho + yOrtho + zOrtho)
neumannDatum = [ufl.as_vector(
tuple(forcingBase * fen.cos(forcingWeight) * kWavedir for kWavedir in kWave)),
ufl.as_vector(
tuple(forcingBase * fen.sin(forcingWeight) * kWavedir for kWavedir in kWave))]
lambda_eff = ufl.conditional(ufl.ge(y, Lhandle), fen.Constant(lambda_),
fen.Constant(Ehandle_ratio * lambda_))
mu_eff = ufl.conditional(ufl.ge(y, Lhandle), fen.Constant(mu_),
fen.Constant(Ehandle_ratio * mu_))
rho_eff = ufl.conditional(ufl.ge(y, Lhandle), fen.Constant(rho),
fen.Constant(rhohandle_ratio * rho))
###
if dampingEta > 0:
solver = LEHPED(degree_threshold = 8, verbosity = 0)
solver.eta = dampingEta
else:
solver = LEHPE(degree_threshold = 8, verbosity = 0)
solver.omega = np.real(k0)
solver.lambda_ = lambda_eff
solver.mu_ = mu_eff
solver.rho_ = rho_eff
solver.V = fen.VectorFunctionSpace(mesh, "P", 1)
solver.DirichletBoundary = lambda x, on_b: on_b and x[1] < Hball
solver.NeumannBoundary = "REST"
solver.forcingTerm = neumannDatum
if algo == "Pade":
approx = Pade(solver, mu0 = k0, approxParameters = params,
verbosity = verb)
else:
params.pop("Delta")
params.pop("polybasis")
params.pop("robustTol")
params.pop("interpRcond")
params.pop("errorEstimatorKind")
approx = RB(solver, mu0 = k0, approxParameters = params,
verbosity = verb)
approx.initEstimatorNormEngine(L2NormMatrix(solver.V))
if timed:
from time import clock
start_time = clock()
approx.greedy()
print("Time: ", clock() - start_time)
else:
approx.greedy(True)
polesApp = approx.getPoles()
print("Poles:\n", polesApp)
approx.samplingEngine.verbosity = 0
approx.verbosity = 0
kl, kr = np.real(kl), np.real(kr)
from matplotlib import pyplot as plt
normApp = np.zeros(len(k0s))
norm = np.zeros_like(normApp)
res = np.zeros_like(normApp)
err = np.zeros_like(normApp)
for j in range(len(k0s)):
normApp[j] = approx.normApprox(k0s[j])
norm[j] = approx.normHF(k0s[j])
res[j] = (approx.estimatorNormEngine.norm(approx.getRes(k0s[j]))
/ approx.estimatorNormEngine.norm(approx.getRHS(k0s[j])))
err[j] = approx.normErr(k0s[j]) / norm[j]
resApp = approx.errorEstimator(k0s)
res[res < 1e-5 * approx.greedyTol] = np.nan
resApp[resApp < 1e-5 * approx.greedyTol] = np.nan
err[err < 1e-8 * approx.greedyTol] = np.nan
plt.figure()
plt.semilogy(k0s, norm)
plt.semilogy(k0s, normApp, '--')
plt.semilogy(np.real(approx.mus),
1.05*np.max(norm)*np.ones_like(approx.mus, dtype = float),
'rx')
plt.xlim([kl, kr])
plt.grid()
plt.show()
plt.close()
plt.figure()
plt.semilogy(k0s, res)
plt.semilogy(k0s, resApp, '--')
plt.semilogy(np.real(approx.mus),
approx.greedyTol*np.ones_like(approx.mus, dtype = float),
'rx')
plt.xlim([kl, kr])
plt.grid()
plt.show()
plt.close()
plt.figure()
plt.semilogy(k0s, err)
plt.xlim([kl, kr])
plt.grid()
plt.show()
plt.close()
mask = (np.real(polesApp) < kl) | (np.real(polesApp) > kr)
print("Outliers:", polesApp[mask])
polesAppEff = polesApp[~mask]
plt.figure()
plt.plot(np.real(polesAppEff), np.imag(polesAppEff), 'kx')
plt.axis('equal')
plt.grid()
plt.show()
plt.close()

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