def test_basic_inversion(self):
"""
Test to see if inversion recovers model
"""
h = [(2, 30)]
meshObj = Mesh.TensorMesh((h, h, [(2, 10)]), x0='CCN')
mod = 0.00025 * np.ones(meshObj.nC)
mod[(meshObj.gridCC[:, 0] > -4.) & (meshObj.gridCC[:, 1] > -4.) &
(meshObj.gridCC[:, 0] < 4.) & (meshObj.gridCC[:, 1] < 4.)] = 0.001
times = np.logspace(-4, -2, 5)
waveObj = VRM.WaveformVRM.SquarePulse(0.02)
x, y = np.meshgrid(np.linspace(-17, 17, 16), np.linspace(-17, 17, 16))
x, y, z = mkvc(x), mkvc(y), 0.5 * np.ones(np.size(x))
rxList = [VRM.Rx.Point(np.c_[x, y, z], times, 'dbdt', 'z')]
txNodes = np.array([[-20, -20, 0.001], [20, -20,
0.001], [20, 20, 0.001],
[-20, 20, 0.01], [-20, -20, 0.001]])
txList = [VRM.Src.LineCurrent(rxList, txNodes, 1., waveObj)]
Survey = VRM.Survey(txList)
Problem = VRM.Problem_Linear(meshObj, refFact=2)
Problem.pair(Survey)
Survey.makeSyntheticData(mod)
Survey.eps = 1e-11
dmis = DataMisfit.l2_DataMisfit(Survey)
W = mkvc((np.sum(np.array(Problem.A)**2, axis=0)))**0.25
reg = Regularization.Simple(meshObj,
alpha_s=0.01,
alpha_x=1.,
alpha_y=1.,
alpha_z=1.,
cell_weights=W)
opt = Optimization.ProjectedGNCG(maxIter=20,
lower=0.,
upper=1e-2,
maxIterLS=20,
tolCG=1e-4)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
directives = [
Directives.BetaSchedule(coolingFactor=2, coolingRate=1),
Directives.TargetMisfit()
]
inv = Inversion.BaseInversion(invProb, directiveList=directives)
m0 = 1e-6 * np.ones(len(mod))
mrec = inv.run(m0)
dmis_final = np.sum(
(dmis.W.diagonal() * (Survey.dobs - Problem.fields(mrec)))**2)
mod_err_2 = np.sqrt(np.sum((mrec - mod)**2)) / np.size(mod)
mod_err_inf = np.max(np.abs(mrec - mod))
self.assertTrue(dmis_final < Survey.nD and mod_err_2 < 5e-6
and mod_err_inf < np.max(mod))
def run(N=100, plotIt=True):
np.random.seed(1)
mesh = Mesh.TensorMesh([N])
nk = 20
jk = np.linspace(1., 60., nk)
p = -0.25
q = 0.25
def g(k):
return (np.exp(p * jk[k] * mesh.vectorCCx) *
np.cos(np.pi * q * jk[k] * mesh.vectorCCx))
G = np.empty((nk, mesh.nC))
for i in range(nk):
G[i, :] = g(i)
mtrue = np.zeros(mesh.nC)
mtrue[mesh.vectorCCx > 0.3] = 1.
mtrue[mesh.vectorCCx > 0.45] = -0.5
mtrue[mesh.vectorCCx > 0.6] = 0
prob = Problem.LinearProblem(mesh, G=G)
survey = Survey.LinearSurvey()
survey.pair(prob)
survey.makeSyntheticData(mtrue, std=0.01)
M = prob.mesh
reg = Regularization.Tikhonov(mesh, alpha_s=1., alpha_x=1.)
dmis = DataMisfit.l2_DataMisfit(survey)
opt = Optimization.InexactGaussNewton(maxIter=60)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
directives = [
Directives.BetaEstimate_ByEig(beta0_ratio=1e-2),
Directives.TargetMisfit()
]
inv = Inversion.BaseInversion(invProb, directiveList=directives)
m0 = np.zeros_like(survey.mtrue)
mrec = inv.run(m0)
if plotIt:
fig, axes = plt.subplots(1, 2, figsize=(12 * 1.2, 4 * 1.2))
for i in range(prob.G.shape[0]):
axes[0].plot(prob.G[i, :])
axes[0].set_title('Columns of matrix G')
axes[1].plot(M.vectorCCx, survey.mtrue, 'b-')
axes[1].plot(M.vectorCCx, mrec, 'r-')
axes[1].legend(('True Model', 'Recovered Model'))
axes[1].set_ylim([-2, 2])
return prob, survey, mesh, mrec
def fit_colecole_with_se(self, eta_cc=0.8, tau_cc=0.003, c_cc=0.6):
def ColeColeSeigel(f, sigmaInf, eta, tau, c):
w = 2 * np.pi * f
return sigmaInf * (1 - eta / (1 + (1j * w * tau)**c))
# Step1: Fit Cole-Cole with Stretched Exponential function
time = np.logspace(-6, np.log10(0.01), 41)
wt, tbase, omega_int = DigFilter.setFrequency(time)
frequency = omega_int / (2 * np.pi)
# Cole-Cole parameters
siginf = 1.
self.eta_cc = eta_cc
self.tau_cc = tau_cc
self.c_cc = c_cc
sigma = ColeColeSeigel(frequency, siginf, eta_cc, tau_cc, c_cc)
sigTCole = DigFilter.transFiltImpulse(sigma,
wt,
tbase,
omega_int,
time,
tol=1e-12)
wires = Maps.Wires(('eta', 1), ('tau', 1), ('c', 1))
taumap = Maps.ExpMap(nP=1) * wires.tau
survey = SESurvey()
dtrue = -sigTCole
survey.dobs = dtrue
m1D = Mesh.TensorMesh([np.ones(3)])
prob = SEInvImpulseProblem(m1D,
etaMap=wires.eta,
tauMap=taumap,
cMap=wires.c)
update_sens = Directives.UpdateSensitivityWeights()
prob.time = time
prob.pair(survey)
m0 = np.r_[eta_cc, np.log(tau_cc), c_cc]
perc = 0.05
dmisfitpeta = DataMisfit.l2_DataMisfit(survey)
dmisfitpeta.W = 1 / (abs(survey.dobs) * perc)
reg = regularization.Simple(m1D)
opt = Optimization.ProjectedGNCG(maxIter=10)
invProb = InvProblem.BaseInvProblem(dmisfitpeta, reg, opt)
# Create an inversion object
target = Directives.TargetMisfit()
invProb.beta = 0.
inv = Inversion.BaseInversion(invProb, directiveList=[target])
reg.mref = 0. * m0
prob.counter = opt.counter = Utils.Counter()
opt.LSshorten = 0.5
opt.remember('xc')
opt.tolX = 1e-20
opt.tolF = 1e-20
opt.tolG = 1e-20
opt.eps = 1e-20
mopt = inv.run(m0)
return mopt
def solve(self):
# Tikhonov Inversion
####################
# Initial model values
m0 = np.median(self.ln_sigback) * np.ones(self.mapping.nP)
m0 += np.random.randn(m0.size)
# Misfit functional
dmis = DataMisfit.l2_DataMisfit(self.survey.simpeg_survey)
# Regularization functional
regT = Regularization.Simple(self.mesh,
alpha_s=10.0,
alpha_x=10.0,
alpha_y=10.0,
alpha_z=10.0,
indActive=self.actind)
# Personal preference for this solver with a Jacobi preconditioner
opt = Optimization.ProjectedGNCG(maxIter=8, tolX=1, maxIterCG=30)
#opt = Optimization.ProjectedGradient(maxIter=100, tolX=1e-2,
# maxIterLS=20, maxIterCG=30, tolCG=1e-4)
opt.printers.append(Optimization.IterationPrinters.iterationLS)
#print(opt.printersLS)
# Optimization class keeps value of 'xc'. Seems to be solution for the model parameters
opt.remember('xc')
invProb = InvProblem.BaseInvProblem(dmis, regT, opt)
# Options for the inversion algorithm in particular selection of Beta weight for regularization.
# How to choose initial estimate for beta
beta = Directives.BetaEstimate_ByEig(beta0_ratio=1.)
Target = Directives.TargetMisfit()
# Beta changing algorithm.
betaSched = Directives.BetaSchedule(coolingFactor=5., coolingRate=2)
# Change model weights, seems sensitivity of conductivity ?? Not sure.
updateSensW = Directives.UpdateSensitivityWeights(threshold=1e-3)
# Use Jacobi preconditioner ( the only available).
update_Jacobi = Directives.UpdatePreconditioner()
inv = Inversion.BaseInversion(invProb,
directiveList=[
beta, Target, betaSched, updateSensW,
update_Jacobi
])
self.minv = inv.run(m0)
def solve(self):
# initial values/model
m0 = numpy.median(-4) * numpy.ones(self.mapping.nP)
# Data Misfit
dataMisfit = DataMisfit.l2_DataMisfit(self.survey)
# Regularization
regT = Regularization.Simple(self.mesh, indActive=self.activeCellIndices, alpha_s=1e-6, alpha_x=1., alpha_y=1., alpha_z=1.)
# Optimization Scheme
opt = Optimization.InexactGaussNewton(maxIter=10)
# Form the problem
opt.remember('xc')
invProb = InvProblem.BaseInvProblem(dataMisfit, regT, opt)
# Directives for Inversions
beta = Directives.BetaEstimate_ByEig(beta0_ratio=0.5e+1)
Target = Directives.TargetMisfit()
betaSched = Directives.BetaSchedule(coolingFactor=5., coolingRate=2)
inversion = Inversion.BaseInversion(invProb, directiveList=[beta, Target, betaSched])
# Run Inversion
self.invModelOnActiveCells = inversion.run(m0)
self.invModelOnAllCells = self.givenModelCond * numpy.ones_like(self.givenModelCond)
self.invModelOnAllCells[self.activeCellIndices] = self.invModelOnActiveCells
self.invModelOnCoreCells = self.invModelOnAllCells[self.coreMeshCellIndices]
pass
def run(plotIt=True,
survey_type="dipole-dipole",
rho_background=1e3,
rho_block=1e2,
block_x0=100,
block_dx=10,
block_y0=-10,
block_dy=5):
np.random.seed(1)
# Initiate I/O class for DC
IO = DC.IO()
# Obtain ABMN locations
xmin, xmax = 0., 200.
ymin, ymax = 0., 0.
zmin, zmax = 0, 0
endl = np.array([[xmin, ymin, zmin], [xmax, ymax, zmax]])
# Generate DC survey object
survey = DC.Utils.gen_DCIPsurvey(endl,
survey_type=survey_type,
dim=2,
a=10,
b=10,
n=10)
survey.getABMN_locations()
survey = IO.from_ambn_locations_to_survey(survey.a_locations,
survey.b_locations,
survey.m_locations,
survey.n_locations,
survey_type,
data_dc_type='volt')
# Obtain 2D TensorMesh
mesh, actind = IO.set_mesh()
# Flat topography
actind = Utils.surface2ind_topo(mesh, np.c_[mesh.vectorCCx,
mesh.vectorCCx * 0.])
survey.drapeTopo(mesh, actind, option="top")
# Use Exponential Map: m = log(rho)
actmap = Maps.InjectActiveCells(mesh,
indActive=actind,
valInactive=np.log(1e8))
parametric_block = Maps.ParametricBlock(mesh, slopeFact=1e2)
mapping = Maps.ExpMap(mesh) * parametric_block
# Set true model
# val_background,val_block, block_x0, block_dx, block_y0, block_dy
mtrue = np.r_[np.log(1e3), np.log(10), 100, 10, -20, 10]
# Set initial model
m0 = np.r_[np.log(rho_background),
np.log(rho_block), block_x0, block_dx, block_y0, block_dy]
rho = mapping * mtrue
rho0 = mapping * m0
# Show the true conductivity model
fig = plt.figure(figsize=(12, 3))
ax = plt.subplot(111)
temp = rho.copy()
temp[~actind] = np.nan
out = mesh.plotImage(temp,
grid=False,
ax=ax,
gridOpts={'alpha': 0.2},
clim=(10, 1000),
pcolorOpts={
"cmap": "viridis",
"norm": colors.LogNorm()
})
ax.plot(survey.electrode_locations[:, 0], survey.electrode_locations[:, 1],
'k.')
ax.set_xlim(IO.grids[:, 0].min(), IO.grids[:, 0].max())
ax.set_ylim(-IO.grids[:, 1].max(), IO.grids[:, 1].min())
cb = plt.colorbar(out[0])
cb.set_label("Resistivity (ohm-m)")
ax.set_aspect('equal')
ax.set_title("True resistivity model")
plt.show()
# Show the true conductivity model
fig = plt.figure(figsize=(12, 3))
ax = plt.subplot(111)
temp = rho0.copy()
temp[~actind] = np.nan
out = mesh.plotImage(temp,
grid=False,
ax=ax,
gridOpts={'alpha': 0.2},
clim=(10, 1000),
pcolorOpts={
"cmap": "viridis",
"norm": colors.LogNorm()
})
ax.plot(survey.electrode_locations[:, 0], survey.electrode_locations[:, 1],
'k.')
ax.set_xlim(IO.grids[:, 0].min(), IO.grids[:, 0].max())
ax.set_ylim(-IO.grids[:, 1].max(), IO.grids[:, 1].min())
cb = plt.colorbar(out[0])
cb.set_label("Resistivity (ohm-m)")
ax.set_aspect('equal')
ax.set_title("Initial resistivity model")
plt.show()
# Generate 2.5D DC problem
# "N" means potential is defined at nodes
prb = DC.Problem2D_N(mesh, rhoMap=mapping, storeJ=True, Solver=Solver)
# Pair problem with survey
try:
prb.pair(survey)
except:
survey.unpair()
prb.pair(survey)
# Make synthetic DC data with 5% Gaussian noise
dtrue = survey.makeSyntheticData(mtrue, std=0.05, force=True)
# Show apparent resisitivty pseudo-section
IO.plotPseudoSection(data=survey.dobs / IO.G,
data_type='apparent_resistivity')
# Show apparent resisitivty histogram
fig = plt.figure()
out = hist(survey.dobs / IO.G, bins=20)
plt.show()
# Set uncertainty
# floor
eps = 10**(-3.2)
# percentage
std = 0.05
dmisfit = DataMisfit.l2_DataMisfit(survey)
uncert = abs(survey.dobs) * std + eps
dmisfit.W = 1. / uncert
# Map for a regularization
mesh_1d = Mesh.TensorMesh([parametric_block.nP])
# Related to inversion
reg = Regularization.Simple(mesh_1d, alpha_x=0.)
opt = Optimization.InexactGaussNewton(maxIter=10)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
beta = Directives.BetaSchedule(coolingFactor=5, coolingRate=2)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1e0)
target = Directives.TargetMisfit()
updateSensW = Directives.UpdateSensitivityWeights()
update_Jacobi = Directives.UpdatePreconditioner()
invProb.beta = 0.
inv = Inversion.BaseInversion(invProb, directiveList=[target])
prb.counter = opt.counter = Utils.Counter()
opt.LSshorten = 0.5
opt.remember('xc')
# Run inversion
mopt = inv.run(m0)
# Convert obtained inversion model to resistivity
# rho = M(m), where M(.) is a mapping
rho_est = mapping * mopt
rho_true = rho.copy()
# show recovered conductivity
vmin, vmax = rho.min(), rho.max()
fig, ax = plt.subplots(2, 1, figsize=(20, 6))
out1 = mesh.plotImage(rho_true,
clim=(10, 1000),
pcolorOpts={
"cmap": "viridis",
"norm": colors.LogNorm()
},
ax=ax[0])
out2 = mesh.plotImage(rho_est,
clim=(10, 1000),
pcolorOpts={
"cmap": "viridis",
"norm": colors.LogNorm()
},
ax=ax[1])
out = [out1, out2]
for i in range(2):
ax[i].plot(survey.electrode_locations[:, 0],
survey.electrode_locations[:, 1], 'kv')
ax[i].set_xlim(IO.grids[:, 0].min(), IO.grids[:, 0].max())
ax[i].set_ylim(-IO.grids[:, 1].max(), IO.grids[:, 1].min())
cb = plt.colorbar(out[i][0], ax=ax[i])
cb.set_label("Resistivity ($\Omega$m)")
ax[i].set_xlabel("Northing (m)")
ax[i].set_ylabel("Elevation (m)")
ax[i].set_aspect('equal')
ax[0].set_title("True resistivity model")
ax[1].set_title("Recovered resistivity model")
plt.tight_layout()
plt.show()
def run_inversion(
m0,
survey,
actind,
mesh,
wires,
std,
eps,
maxIter=15,
beta0_ratio=1e0,
coolingFactor=2,
coolingRate=2,
maxIterLS=20,
maxIterCG=10,
LSshorten=0.5,
eta_lower=1e-5,
eta_upper=1,
tau_lower=1e-6,
tau_upper=10.,
c_lower=1e-2,
c_upper=1.,
is_log_tau=True,
is_log_c=True,
is_log_eta=True,
mref=None,
alpha_s=1e-4,
alpha_x=1e0,
alpha_y=1e0,
alpha_z=1e0,
):
"""
Run Spectral Spectral IP inversion
"""
dmisfit = DataMisfit.l2_DataMisfit(survey)
uncert = abs(survey.dobs) * std + eps
dmisfit.W = 1. / uncert
# Map for a regularization
# Related to inversion
# Set Upper and Lower bounds
e = np.ones(actind.sum())
if np.isscalar(eta_lower):
eta_lower = e * eta_lower
if np.isscalar(tau_lower):
tau_lower = e * tau_lower
if np.isscalar(c_lower):
c_lower = e * c_lower
if np.isscalar(eta_upper):
eta_upper = e * eta_upper
if np.isscalar(tau_upper):
tau_upper = e * tau_upper
if np.isscalar(c_upper):
c_upper = e * c_upper
if is_log_eta:
eta_upper = np.log(eta_upper)
eta_lower = np.log(eta_lower)
if is_log_tau:
tau_upper = np.log(tau_upper)
tau_lower = np.log(tau_lower)
if is_log_c:
c_upper = np.log(c_upper)
c_lower = np.log(c_lower)
m_upper = np.r_[eta_upper, tau_upper, c_upper]
m_lower = np.r_[eta_lower, tau_lower, c_lower]
# Set up regularization
reg_eta = Regularization.Tikhonov(mesh,
mapping=wires.eta,
indActive=actind)
reg_tau = Regularization.Tikhonov(mesh,
mapping=wires.tau,
indActive=actind)
reg_c = Regularization.Tikhonov(mesh, mapping=wires.c, indActive=actind)
# Todo:
reg_eta.alpha_s = alpha_s
reg_tau.alpha_s = alpha_s
reg_c.alpha_s = alpha_s
reg_eta.alpha_x = alpha_x
reg_tau.alpha_x = alpha_x
reg_c.alpha_x = alpha_x
reg_eta.alpha_y = alpha_y
reg_tau.alpha_y = alpha_y
reg_c.alpha_y = alpha_y
reg_eta.alpha_z = alpha_z
reg_tau.alpha_z = alpha_z
reg_c.alpha_z = alpha_z
reg = reg_eta + reg_tau + reg_c
# Use Projected Gauss Newton scheme
opt = Optimization.ProjectedGNCG(maxIter=maxIter,
upper=m_upper,
lower=m_lower,
maxIterLS=maxIterLS,
maxIterCG=maxIterCG,
LSshorten=LSshorten)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
beta = Directives.BetaSchedule(coolingFactor=coolingFactor,
coolingRate=coolingRate)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=beta0_ratio)
target = Directives.TargetMisfit()
directiveList = [beta, betaest, target]
inv = Inversion.BaseInversion(invProb, directiveList=directiveList)
opt.LSshorten = 0.5
opt.remember('xc')
# Run inversion
mopt = inv.run(m0)
return mopt, invProb.dpred
def run(plotIt=True):
"""
1D FDEM Mu Inversion
====================
1D inversion of Magnetic Susceptibility from FDEM data assuming a fixed
electrical conductivity
"""
# Set up cylindrically symmeric mesh
cs, ncx, ncz, npad = 10., 15, 25, 13 # padded cyl mesh
hx = [(cs, ncx), (cs, npad, 1.3)]
hz = [(cs, npad, -1.3), (cs, ncz), (cs, npad, 1.3)]
mesh = Mesh.CylMesh([hx, 1, hz], '00C')
# Geologic Parameters model
layerz = np.r_[-100., -50.]
layer = (mesh.vectorCCz >= layerz[0]) & (mesh.vectorCCz <= layerz[1])
active = mesh.vectorCCz < 0.
# Electrical Conductivity
sig_half = 1e-2 # Half-space conductivity
sig_air = 1e-8 # Air conductivity
sig_layer = 1e-2 # Layer conductivity
sigma = np.ones(mesh.nCz) * sig_air
sigma[active] = sig_half
sigma[layer] = sig_layer
# mur - relative magnetic permeability
mur_half = 1.
mur_air = 1.
mur_layer = 2.
mur = np.ones(mesh.nCz) * mur_air
mur[active] = mur_half
mur[layer] = mur_layer
mtrue = mur[active]
# Maps
actMap = Maps.InjectActiveCells(mesh, active, mur_air, nC=mesh.nCz)
surj1Dmap = Maps.SurjectVertical1D(mesh)
murMap = Maps.MuRelative(mesh)
# Mapping
muMap = murMap * surj1Dmap * actMap
# ----- FDEM problem & survey -----
rxlocs = Utils.ndgrid([np.r_[10.], np.r_[0], np.r_[30.]])
bzr = FDEM.Rx.Point_bSecondary(rxlocs, 'z', 'real')
# bzi = FDEM.Rx.Point_bSecondary(rxlocs, 'z', 'imag')
freqs = np.linspace(2000, 10000, 10) #np.logspace(3, 4, 10)
srcLoc = np.array([0., 0., 30.])
print('min skin depth = ', 500. / np.sqrt(freqs.max() * sig_half),
'max skin depth = ', 500. / np.sqrt(freqs.min() * sig_half))
print('max x ', mesh.vectorCCx.max(), 'min z ', mesh.vectorCCz.min(),
'max z ', mesh.vectorCCz.max())
srcList = [
FDEM.Src.MagDipole([bzr], freq, srcLoc, orientation='Z')
for freq in freqs
]
surveyFD = FDEM.Survey(srcList)
prbFD = FDEM.Problem3D_b(mesh,
sigma=surj1Dmap * sigma,
muMap=muMap,
Solver=Solver)
prbFD.pair(surveyFD)
std = 0.03
surveyFD.makeSyntheticData(mtrue, std)
surveyFD.eps = np.linalg.norm(surveyFD.dtrue) * 1e-6
# FDEM inversion
np.random.seed(13472)
dmisfit = DataMisfit.l2_DataMisfit(surveyFD)
regMesh = Mesh.TensorMesh([mesh.hz[muMap.maps[-1].indActive]])
reg = Regularization.Simple(regMesh)
opt = Optimization.InexactGaussNewton(maxIterCG=10)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
# Inversion Directives betaest = Directives.BetaEstimate_ByEig(beta0_ratio=2.)
beta = Directives.BetaSchedule(coolingFactor=4, coolingRate=3)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=2.)
target = Directives.TargetMisfit()
directiveList = [beta, betaest, target]
inv = Inversion.BaseInversion(invProb, directiveList=directiveList)
m0 = mur_half * np.ones(mtrue.size)
reg.alpha_s = 2e-2
reg.alpha_x = 1.
prbFD.counter = opt.counter = Utils.Counter()
opt.remember('xc')
moptFD = inv.run(m0)
dpredFD = surveyFD.dpred(moptFD)
if plotIt:
fig, ax = plt.subplots(1, 3, figsize=(10, 6))
fs = 13 # fontsize
matplotlib.rcParams['font.size'] = fs
# Plot the conductivity model
ax[0].semilogx(sigma[active], mesh.vectorCCz[active], 'k-', lw=2)
ax[0].set_ylim(-500, 0)
ax[0].set_xlim(5e-3, 1e-1)
ax[0].set_xlabel('Conductivity (S/m)', fontsize=fs)
ax[0].set_ylabel('Depth (m)', fontsize=fs)
ax[0].grid(which='both',
color='k',
alpha=0.5,
linestyle='-',
linewidth=0.2)
ax[0].legend(['Conductivity Model'], fontsize=fs, loc=4)
# Plot the permeability model
ax[1].plot(mur[active], mesh.vectorCCz[active], 'k-', lw=2)
ax[1].plot(moptFD, mesh.vectorCCz[active], 'b-', lw=2)
ax[1].set_ylim(-500, 0)
ax[1].set_xlim(0.5, 2.1)
ax[1].set_xlabel('Relative Permeability', fontsize=fs)
ax[1].set_ylabel('Depth (m)', fontsize=fs)
ax[1].grid(which='both',
color='k',
alpha=0.5,
linestyle='-',
linewidth=0.2)
ax[1].legend(['True', 'Predicted'], fontsize=fs, loc=4)
# plot the data misfits - negative b/c we choose positive to be in the
# direction of primary
ax[2].plot(freqs, -surveyFD.dobs, 'k-', lw=2)
# ax[2].plot(freqs, -surveyFD.dobs[1::2], 'k--', lw=2)
ax[2].loglog(freqs, -dpredFD, 'bo', ms=6)
# ax[2].loglog(freqs, -dpredFD[1::2], 'b+', markeredgewidth=2., ms=10)
# Labels, gridlines, etc
ax[2].grid(which='both', alpha=0.5, linestyle='-', linewidth=0.2)
ax[2].grid(which='both', alpha=0.5, linestyle='-', linewidth=0.2)
ax[2].set_xlabel('Frequency (Hz)', fontsize=fs)
ax[2].set_ylabel('Vertical magnetic field (-T)', fontsize=fs)
# ax[2].legend(("Obs", "Pred"), fontsize=fs)
ax[2].legend(("z-Obs (real)", "z-Pred (real)"), fontsize=fs)
ax[2].set_xlim(freqs.max(), freqs.min())
ax[0].set_title("(a) Conductivity Model", fontsize=fs)
ax[1].set_title("(b) $\mu_r$ Model", fontsize=fs)
ax[2].set_title("(c) FDEM observed vs. predicted", fontsize=fs)
# ax[2].set_title("(c) TDEM observed vs. predicted", fontsize=fs)
plt.tight_layout(pad=1.5)
def run(plotIt=True):
M = Mesh.TensorMesh([np.ones(40)], x0='N')
M.setCellGradBC('dirichlet')
# We will use the haverkamp empirical model with parameters from Celia1990
k_fun, theta_fun = Richards.Empirical.haverkamp(M,
A=1.1750e+06,
gamma=4.74,
alpha=1.6110e+06,
theta_s=0.287,
theta_r=0.075,
beta=3.96)
# Here we are making saturated hydraulic conductivity
# an exponential mapping to the model (defined below)
k_fun.KsMap = Maps.ExpMap(nP=M.nC)
# Setup the boundary and initial conditions
bc = np.array([-61.5, -20.7])
h = np.zeros(M.nC) + bc[0]
prob = Richards.RichardsProblem(M,
hydraulic_conductivity=k_fun,
water_retention=theta_fun,
boundary_conditions=bc,
initial_conditions=h,
do_newton=False,
method='mixed',
debug=False)
prob.timeSteps = [(5, 25, 1.1), (60, 40)]
# Create the survey
locs = -np.arange(2, 38, 4.)
times = np.arange(30, prob.timeMesh.vectorCCx[-1], 60)
rxSat = Richards.SaturationRx(locs, times)
survey = Richards.RichardsSurvey([rxSat])
survey.pair(prob)
# Create a simple model for Ks
Ks = 1e-3
mtrue = np.ones(M.nC) * np.log(Ks)
mtrue[15:20] = np.log(5e-2)
mtrue[20:35] = np.log(3e-3)
mtrue[35:40] = np.log(1e-2)
m0 = np.ones(M.nC) * np.log(Ks)
# Create some synthetic data and fields
stdev = 0.02 # The standard deviation for the noise
Hs = prob.fields(mtrue)
survey.makeSyntheticData(mtrue, std=stdev, f=Hs, force=True)
# Setup a pretty standard inversion
reg = Regularization.Tikhonov(M, alpha_s=1e-1)
dmis = DataMisfit.l2_DataMisfit(survey)
opt = Optimization.InexactGaussNewton(maxIter=20, maxIterCG=10)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
beta = Directives.BetaSchedule(coolingFactor=4)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1e2)
target = Directives.TargetMisfit()
dir_list = [beta, betaest, target]
inv = Inversion.BaseInversion(invProb, directiveList=dir_list)
mopt = inv.run(m0)
Hs_opt = prob.fields(mopt)
if plotIt:
plt.figure(figsize=(14, 9))
ax = plt.subplot(121)
plt.semilogx(np.exp(np.c_[mopt, mtrue]), M.gridCC)
plt.xlabel('Saturated Hydraulic Conductivity, $K_s$')
plt.ylabel('Depth, cm')
plt.semilogx([10**-3.9] * len(locs), locs, 'ro')
plt.legend(('$m_{rec}$', '$m_{true}$', 'Data locations'), loc=4)
ax = plt.subplot(222)
mesh2d = Mesh.TensorMesh([prob.timeMesh.hx / 60, prob.mesh.hx], '0N')
sats = [theta_fun(_) for _ in Hs]
clr = mesh2d.plotImage(np.c_[sats][1:, :], ax=ax)
cmap0 = matplotlib.cm.RdYlBu_r
clr[0].set_cmap(cmap0)
c = plt.colorbar(clr[0])
c.set_label('Saturation $\\theta$')
plt.xlabel('Time, minutes')
plt.ylabel('Depth, cm')
plt.title('True saturation over time')
ax = plt.subplot(224)
mesh2d = Mesh.TensorMesh([prob.timeMesh.hx / 60, prob.mesh.hx], '0N')
sats = [theta_fun(_) for _ in Hs_opt]
clr = mesh2d.plotImage(np.c_[sats][1:, :], ax=ax)
cmap0 = matplotlib.cm.RdYlBu_r
clr[0].set_cmap(cmap0)
c = plt.colorbar(clr[0])
c.set_label('Saturation $\\theta$')
plt.xlabel('Time, minutes')
plt.ylabel('Depth, cm')
plt.title('Recovered saturation over time')
plt.tight_layout()
def run_inversion_cg(
self,
maxIter=60,
m0=0.0,
mref=0.0,
percentage=5,
floor=0.1,
chifact=1,
beta0_ratio=1.0,
coolingFactor=1,
coolingRate=1,
alpha_s=1.0,
alpha_x=1.0,
use_target=False,
):
survey, prob = self.get_problem_survey()
survey.eps = percentage
survey.std = floor
survey.dobs = self.data.copy()
self.uncertainty = percentage * abs(survey.dobs) * 0.01 + floor
m0 = np.ones(self.M) * m0
mref = np.ones(self.M) * mref
reg = Regularization.Tikhonov(
self.mesh, alpha_s=alpha_s, alpha_x=alpha_x, mref=mref
)
dmis = DataMisfit.l2_DataMisfit(survey)
dmis.W = 1.0 / self.uncertainty
opt = Optimization.InexactGaussNewton(maxIter=maxIter, maxIterCG=20)
opt.remember("xc")
opt.tolG = 1e-10
opt.eps = 1e-10
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
save = Directives.SaveOutputEveryIteration()
beta_schedule = Directives.BetaSchedule(
coolingFactor=coolingFactor, coolingRate=coolingRate
)
target = Directives.TargetMisfit(chifact=chifact)
if use_target:
directives = [
Directives.BetaEstimate_ByEig(beta0_ratio=beta0_ratio),
beta_schedule,
target,
save,
]
else:
directives = [
Directives.BetaEstimate_ByEig(beta0_ratio=beta0_ratio),
beta_schedule,
save,
]
inv = Inversion.BaseInversion(invProb, directiveList=directives)
mopt = inv.run(m0)
model = opt.recall("xc")
model.append(mopt)
pred = []
for m in model:
pred.append(survey.dpred(m))
return model, pred, save
# Define misfit function (obs-calc)
dmis = DataMisfit.l2_DataMisfit(survey)
dmis.W = 1./survey.std
# Create the default L2 inverse problem from the above objects
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
# Specify how the initial beta is found
betaest = Directives.BetaEstimate_ByEig()
# Beta schedule for inversion
betaSchedule = Directives.BetaSchedule(coolingFactor=2., coolingRate=1)
# Target misfit to stop the inversion,
# try to fit as much as possible of the signal, we don't want to lose anything
targetMisfit = Directives.TargetMisfit(chifact=0.1)
# Put all the parts together
inv = Inversion.BaseInversion(invProb,
directiveList=[betaest, betaSchedule, targetMisfit])
# Run the equivalent source inversion
mstart = np.zeros(nC)
mrec = inv.run(mstart)
# Ouput result
Mesh.TensorMesh.writeModelUBC(mesh, work_dir + out_dir + "EquivalentSource.sus", surfMap*mrec)
# %% STEP 2: COMPUTE AMPLITUDE DATA
# Now that we have an equialent source layer, we can forward model alh three
def run(plotIt=True, saveFig=False):
# Set up cylindrically symmeric mesh
cs, ncx, ncz, npad = 10., 15, 25, 13 # padded cyl mesh
hx = [(cs, ncx), (cs, npad, 1.3)]
hz = [(cs, npad, -1.3), (cs, ncz), (cs, npad, 1.3)]
mesh = Mesh.CylMesh([hx, 1, hz], '00C')
# Conductivity model
layerz = np.r_[-200., -100.]
layer = (mesh.vectorCCz >= layerz[0]) & (mesh.vectorCCz <= layerz[1])
active = mesh.vectorCCz < 0.
sig_half = 1e-2 # Half-space conductivity
sig_air = 1e-8 # Air conductivity
sig_layer = 5e-2 # Layer conductivity
sigma = np.ones(mesh.nCz) * sig_air
sigma[active] = sig_half
sigma[layer] = sig_layer
# Mapping
actMap = Maps.InjectActiveCells(mesh, active, np.log(1e-8), nC=mesh.nCz)
mapping = Maps.ExpMap(mesh) * Maps.SurjectVertical1D(mesh) * actMap
mtrue = np.log(sigma[active])
# ----- FDEM problem & survey ----- #
rxlocs = Utils.ndgrid([np.r_[50.], np.r_[0], np.r_[0.]])
bzr = FDEM.Rx.Point_bSecondary(rxlocs, 'z', 'real')
bzi = FDEM.Rx.Point_bSecondary(rxlocs, 'z', 'imag')
freqs = np.logspace(2, 3, 5)
srcLoc = np.array([0., 0., 0.])
print('min skin depth = ', 500. / np.sqrt(freqs.max() * sig_half),
'max skin depth = ', 500. / np.sqrt(freqs.min() * sig_half))
print('max x ', mesh.vectorCCx.max(), 'min z ', mesh.vectorCCz.min(),
'max z ', mesh.vectorCCz.max())
srcList = [
FDEM.Src.MagDipole([bzr, bzi], freq, srcLoc, orientation='Z')
for freq in freqs
]
surveyFD = FDEM.Survey(srcList)
prbFD = FDEM.Problem3D_b(mesh, sigmaMap=mapping, Solver=Solver)
prbFD.pair(surveyFD)
std = 0.03
surveyFD.makeSyntheticData(mtrue, std)
surveyFD.eps = np.linalg.norm(surveyFD.dtrue) * 1e-5
# FDEM inversion
np.random.seed(1)
dmisfit = DataMisfit.l2_DataMisfit(surveyFD)
regMesh = Mesh.TensorMesh([mesh.hz[mapping.maps[-1].indActive]])
reg = Regularization.Simple(regMesh)
opt = Optimization.InexactGaussNewton(maxIterCG=10)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
# Inversion Directives
beta = Directives.BetaSchedule(coolingFactor=4, coolingRate=3)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=2.)
target = Directives.TargetMisfit()
directiveList = [beta, betaest, target]
inv = Inversion.BaseInversion(invProb, directiveList=directiveList)
m0 = np.log(np.ones(mtrue.size) * sig_half)
reg.alpha_s = 5e-1
reg.alpha_x = 1.
prbFD.counter = opt.counter = Utils.Counter()
opt.remember('xc')
moptFD = inv.run(m0)
# TDEM problem
times = np.logspace(-4, np.log10(2e-3), 10)
print('min diffusion distance ',
1.28 * np.sqrt(times.min() / (sig_half * mu_0)),
'max diffusion distance ',
1.28 * np.sqrt(times.max() / (sig_half * mu_0)))
rx = TDEM.Rx.Point_b(rxlocs, times, 'z')
src = TDEM.Src.MagDipole(
[rx],
waveform=TDEM.Src.StepOffWaveform(),
loc=srcLoc # same src location as FDEM problem
)
surveyTD = TDEM.Survey([src])
prbTD = TDEM.Problem3D_b(mesh, sigmaMap=mapping, Solver=Solver)
prbTD.timeSteps = [(5e-5, 10), (1e-4, 10), (5e-4, 10)]
prbTD.pair(surveyTD)
std = 0.03
surveyTD.makeSyntheticData(mtrue, std)
surveyTD.std = std
surveyTD.eps = np.linalg.norm(surveyTD.dtrue) * 1e-5
# TDEM inversion
dmisfit = DataMisfit.l2_DataMisfit(surveyTD)
regMesh = Mesh.TensorMesh([mesh.hz[mapping.maps[-1].indActive]])
reg = Regularization.Simple(regMesh)
opt = Optimization.InexactGaussNewton(maxIterCG=10)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
# directives
beta = Directives.BetaSchedule(coolingFactor=4, coolingRate=3)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=2.)
target = Directives.TargetMisfit()
directiveList = [beta, betaest, target]
inv = Inversion.BaseInversion(invProb, directiveList=directiveList)
m0 = np.log(np.ones(mtrue.size) * sig_half)
reg.alpha_s = 5e-1
reg.alpha_x = 1.
prbTD.counter = opt.counter = Utils.Counter()
opt.remember('xc')
moptTD = inv.run(m0)
# Plot the results
if plotIt:
plt.figure(figsize=(10, 8))
ax0 = plt.subplot2grid((2, 2), (0, 0), rowspan=2)
ax1 = plt.subplot2grid((2, 2), (0, 1))
ax2 = plt.subplot2grid((2, 2), (1, 1))
fs = 13 # fontsize
matplotlib.rcParams['font.size'] = fs
# Plot the model
ax0.semilogx(sigma[active],
mesh.vectorCCz[active],
'k-',
lw=2,
label="True")
ax0.semilogx(np.exp(moptFD),
mesh.vectorCCz[active],
'bo',
ms=6,
markeredgecolor='k',
markeredgewidth=0.5,
label="FDEM")
ax0.semilogx(np.exp(moptTD),
mesh.vectorCCz[active],
'r*',
ms=10,
markeredgecolor='k',
markeredgewidth=0.5,
label="TDEM")
ax0.set_ylim(-700, 0)
ax0.set_xlim(5e-3, 1e-1)
ax0.set_xlabel('Conductivity (S/m)', fontsize=fs)
ax0.set_ylabel('Depth (m)', fontsize=fs)
ax0.grid(which='both',
color='k',
alpha=0.5,
linestyle='-',
linewidth=0.2)
ax0.legend(fontsize=fs, loc=4)
# plot the data misfits - negative b/c we choose positive to be in the
# direction of primary
ax1.plot(freqs, -surveyFD.dobs[::2], 'k-', lw=2, label="Obs (real)")
ax1.plot(freqs, -surveyFD.dobs[1::2], 'k--', lw=2, label="Obs (imag)")
dpredFD = surveyFD.dpred(moptTD)
ax1.loglog(freqs,
-dpredFD[::2],
'bo',
ms=6,
markeredgecolor='k',
markeredgewidth=0.5,
label="Pred (real)")
ax1.loglog(freqs,
-dpredFD[1::2],
'b+',
ms=10,
markeredgewidth=2.,
label="Pred (imag)")
ax2.loglog(times, surveyTD.dobs, 'k-', lw=2, label='Obs')
ax2.loglog(times,
surveyTD.dpred(moptTD),
'r*',
ms=10,
markeredgecolor='k',
markeredgewidth=0.5,
label='Pred')
ax2.set_xlim(times.min() - 1e-5, times.max() + 1e-4)
# Labels, gridlines, etc
ax2.grid(which='both', alpha=0.5, linestyle='-', linewidth=0.2)
ax1.grid(which='both', alpha=0.5, linestyle='-', linewidth=0.2)
ax1.set_xlabel('Frequency (Hz)', fontsize=fs)
ax1.set_ylabel('Vertical magnetic field (-T)', fontsize=fs)
ax2.set_xlabel('Time (s)', fontsize=fs)
ax2.set_ylabel('Vertical magnetic field (T)', fontsize=fs)
ax2.legend(fontsize=fs, loc=3)
ax1.legend(fontsize=fs, loc=3)
ax1.set_xlim(freqs.max() + 1e2, freqs.min() - 1e1)
ax0.set_title("(a) Recovered Models", fontsize=fs)
ax1.set_title("(b) FDEM observed vs. predicted", fontsize=fs)
ax2.set_title("(c) TDEM observed vs. predicted", fontsize=fs)
plt.tight_layout(pad=1.5)
if saveFig is True:
plt.savefig('example1.png', dpi=600)
hz,
dim=3,
use_cell_weights=True,
minimum_distance=1e3)
np.random.seed(1)
dmisfit = DataMisfit.l2_DataMisfit(survey)
dmisfit.W = 1. / uncert
opt = Optimization.ProjectedGNCG(maxIter=10, maxIterCG=20)
# opt.upper = m_upper
# opt.lower = m_lower
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
beta = Directives.BetaSchedule(coolingFactor=2, coolingRate=1)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1.)
target = Directives.TargetMisfit(chifact=1.)
save_model = Directives.SaveOutputDictEveryIteration(
directory=output_dir.as_posix())
inv = Inversion.BaseInversion(
invProb, directiveList=[beta, betaest, target, save_model])
prob.counter = opt.counter = Utils.Counter()
opt.LSshorten = 0.5
opt.remember('xc')
try:
save_model.outDict = {}
except:
pass
print('Target misfit:', target.target)
## Run it!
def run(plotIt=True, survey_type="dipole-dipole"):
np.random.seed(1)
# Initiate I/O class for DC
IO = DC.IO()
# Obtain ABMN locations
xmin, xmax = 0., 200.
ymin, ymax = 0., 0.
zmin, zmax = 0, 0
endl = np.array([[xmin, ymin, zmin], [xmax, ymax, zmax]])
# Generate DC survey object
survey = DC.Utils.gen_DCIPsurvey(endl, survey_type=survey_type, dim=2,
a=10, b=10, n=10)
survey.getABMN_locations()
survey = IO.from_ambn_locations_to_survey(
survey.a_locations, survey.b_locations,
survey.m_locations, survey.n_locations,
survey_type, data_dc_type='volt'
)
# Obtain 2D TensorMesh
mesh, actind = IO.set_mesh()
topo, mesh1D = DC.Utils.genTopography(mesh, -10, 0, its=100)
actind = Utils.surface2ind_topo(mesh, np.c_[mesh1D.vectorCCx, topo])
survey.drapeTopo(mesh, actind, option="top")
# Build a conductivity model
blk_inds_c = Utils.ModelBuilder.getIndicesSphere(
np.r_[60., -25.], 12.5, mesh.gridCC
)
blk_inds_r = Utils.ModelBuilder.getIndicesSphere(
np.r_[140., -25.], 12.5, mesh.gridCC
)
layer_inds = mesh.gridCC[:, 1] > -5.
sigma = np.ones(mesh.nC)*1./100.
sigma[blk_inds_c] = 1./10.
sigma[blk_inds_r] = 1./1000.
sigma[~actind] = 1./1e8
rho = 1./sigma
# Show the true conductivity model
if plotIt:
fig = plt.figure(figsize=(12, 3))
ax = plt.subplot(111)
temp = rho.copy()
temp[~actind] = np.nan
out = mesh.plotImage(
temp, grid=True, ax=ax, gridOpts={'alpha': 0.2},
clim=(10, 1000),
pcolorOpts={"cmap": "viridis", "norm": colors.LogNorm()}
)
ax.plot(
survey.electrode_locations[:, 0],
survey.electrode_locations[:, 1], 'k.'
)
ax.set_xlim(IO.grids[:, 0].min(), IO.grids[:, 0].max())
ax.set_ylim(-IO.grids[:, 1].max(), IO.grids[:, 1].min())
cb = plt.colorbar(out[0])
cb.set_label("Resistivity (ohm-m)")
ax.set_aspect('equal')
plt.show()
# Use Exponential Map: m = log(rho)
actmap = Maps.InjectActiveCells(
mesh, indActive=actind, valInactive=np.log(1e8)
)
mapping = Maps.ExpMap(mesh) * actmap
# Generate mtrue
mtrue = np.log(rho[actind])
# Generate 2.5D DC problem
# "N" means potential is defined at nodes
prb = DC.Problem2D_N(
mesh, rhoMap=mapping, storeJ=True,
Solver=Solver
)
# Pair problem with survey
try:
prb.pair(survey)
except:
survey.unpair()
prb.pair(survey)
geometric_factor = survey.set_geometric_factor(
data_type="apparent_resistivity",
survey_type='dipole-dipole',
space_type='half-space'
)
# Make synthetic DC data with 5% Gaussian noise
dtrue = survey.makeSyntheticData(mtrue, std=0.05, force=True)
IO.data_dc = dtrue
# Show apparent resisitivty pseudo-section
if plotIt:
IO.plotPseudoSection(
data=survey.dobs, data_type='apparent_resistivity'
)
# Show apparent resisitivty histogram
if plotIt:
fig = plt.figure()
out = hist(survey.dobs, bins=20)
plt.xlabel("Apparent Resisitivty ($\Omega$m)")
plt.show()
# Set initial model based upon histogram
m0 = np.ones(actmap.nP)*np.log(100.)
# Set uncertainty
# floor (10 ohm-m)
eps = 1.
# percentage
std = 0.05
dmisfit = DataMisfit.l2_DataMisfit(survey)
uncert = abs(survey.dobs) * std + eps
dmisfit.W = 1./uncert
# Map for a regularization
regmap = Maps.IdentityMap(nP=int(actind.sum()))
# Related to inversion
reg = Regularization.Sparse(mesh, indActive=actind, mapping=regmap)
opt = Optimization.InexactGaussNewton(maxIter=15)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
beta = Directives.BetaSchedule(coolingFactor=5, coolingRate=2)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1e0)
target = Directives.TargetMisfit()
updateSensW = Directives.UpdateSensitivityWeights()
update_Jacobi = Directives.UpdatePreconditioner()
inv = Inversion.BaseInversion(
invProb, directiveList=[
beta, betaest, target, updateSensW, update_Jacobi
]
)
prb.counter = opt.counter = Utils.Counter()
opt.LSshorten = 0.5
opt.remember('xc')
# Run inversion
mopt = inv.run(m0)
# Get diag(JtJ)
mask_inds = np.ones(mesh.nC, dtype=bool)
jtj = np.sqrt(updateSensW.JtJdiag[0])
jtj /= jtj.max()
temp = np.ones_like(jtj, dtype=bool)
temp[jtj > 0.005] = False
mask_inds[actind] = temp
actind_final = np.logical_and(actind, ~mask_inds)
jtj_cc = np.ones(mesh.nC)*np.nan
jtj_cc[actind] = jtj
# Show the sensitivity
if plotIt:
fig = plt.figure(figsize=(12, 3))
ax = plt.subplot(111)
temp = rho.copy()
temp[~actind] = np.nan
out = mesh.plotImage(
jtj_cc, grid=True, ax=ax,
gridOpts={'alpha': 0.2}, clim=(0.005, 0.5),
pcolorOpts={"cmap": "viridis", "norm": colors.LogNorm()}
)
ax.plot(
survey.electrode_locations[:, 0],
survey.electrode_locations[:, 1], 'k.'
)
ax.set_xlim(IO.grids[:, 0].min(), IO.grids[:, 0].max())
ax.set_ylim(-IO.grids[:, 1].max(), IO.grids[:, 1].min())
cb = plt.colorbar(out[0])
cb.set_label("Sensitivity")
ax.set_aspect('equal')
plt.show()
# Convert obtained inversion model to resistivity
# rho = M(m), where M(.) is a mapping
rho_est = mapping*mopt
rho_est[~actind_final] = np.nan
rho_true = rho.copy()
rho_true[~actind_final] = np.nan
# show recovered conductivity
if plotIt:
vmin, vmax = rho.min(), rho.max()
fig, ax = plt.subplots(2, 1, figsize=(20, 6))
out1 = mesh.plotImage(
rho_true, clim=(10, 1000),
pcolorOpts={"cmap": "viridis", "norm": colors.LogNorm()},
ax=ax[0]
)
out2 = mesh.plotImage(
rho_est, clim=(10, 1000),
pcolorOpts={"cmap": "viridis", "norm": colors.LogNorm()},
ax=ax[1]
)
out = [out1, out2]
for i in range(2):
ax[i].plot(
survey.electrode_locations[:, 0],
survey.electrode_locations[:, 1], 'kv'
)
ax[i].set_xlim(IO.grids[:, 0].min(), IO.grids[:, 0].max())
ax[i].set_ylim(-IO.grids[:, 1].max(), IO.grids[:, 1].min())
cb = plt.colorbar(out[i][0], ax=ax[i])
cb.set_label("Resistivity ($\Omega$m)")
ax[i].set_xlabel("Northing (m)")
ax[i].set_ylabel("Elevation (m)")
ax[i].set_aspect('equal')
plt.tight_layout()
plt.show()
def run(plotIt=True):
"""
EM: TDEM: 1D: Inversion with VTEM waveform
==========================================
Here we will create and run a TDEM 1D inversion,
with VTEM waveform of which initial condition
is zero, but have some on- and off-time.
"""
cs, ncx, ncz, npad = 5., 25, 24, 15
hx = [(cs, ncx), (cs, npad, 1.3)]
hz = [(cs, npad, -1.3), (cs, ncz), (cs, npad, 1.3)]
mesh = Mesh.CylMesh([hx, 1, hz], '00C')
active = mesh.vectorCCz < 0.
layer = (mesh.vectorCCz < -50.) & (mesh.vectorCCz >= -150.)
actMap = Maps.InjectActiveCells(mesh, active, np.log(1e-8), nC=mesh.nCz)
mapping = Maps.ExpMap(mesh) * Maps.SurjectVertical1D(mesh) * actMap
sig_half = 1e-3
sig_air = 1e-8
sig_layer = 1e-2
sigma = np.ones(mesh.nCz) * sig_air
sigma[active] = sig_half
sigma[layer] = sig_layer
mtrue = np.log(sigma[active])
x = np.r_[30, 50, 70, 90]
rxloc = np.c_[x, x * 0., np.zeros_like(x)]
prb = EM.TDEM.Problem3D_b(mesh, sigmaMap=mapping)
prb.Solver = Solver
prb.timeSteps = [(1e-3, 5), (1e-4, 5), (5e-5, 10), (5e-5, 5), (1e-4, 10),
(5e-4, 10)]
# Use VTEM waveform
out = EM.Utils.VTEMFun(prb.times, 0.00595, 0.006, 100)
# Forming function handle for waveform using 1D linear interpolation
wavefun = interp1d(prb.times, out)
t0 = 0.006
waveform = EM.TDEM.Src.RawWaveform(offTime=t0, waveFct=wavefun)
rx = EM.TDEM.Rx.Point_dbdt(rxloc, np.logspace(-4, -2.5, 11) + t0, 'z')
src = EM.TDEM.Src.CircularLoop([rx],
waveform=waveform,
loc=np.array([0., 0., 0.]),
radius=10.)
survey = EM.TDEM.Survey([src])
prb.pair(survey)
# create observed data
std = 0.02
survey.dobs = survey.makeSyntheticData(mtrue, std)
# dobs = survey.dpred(mtrue)
survey.std = std
survey.eps = 1e-11
dmisfit = DataMisfit.l2_DataMisfit(survey)
regMesh = Mesh.TensorMesh([mesh.hz[mapping.maps[-1].indActive]])
reg = Regularization.Simple(regMesh)
opt = Optimization.InexactGaussNewton(maxIter=5, LSshorten=0.5)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
target = Directives.TargetMisfit()
# Create an inversion object
beta = Directives.BetaSchedule(coolingFactor=1., coolingRate=2.)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1e0)
invProb.beta = 1e2
inv = Inversion.BaseInversion(invProb, directiveList=[beta, target])
m0 = np.log(np.ones(mtrue.size) * sig_half)
prb.counter = opt.counter = Utils.Counter()
opt.remember('xc')
mopt = inv.run(m0)
if plotIt:
fig, ax = plt.subplots(1, 2, figsize=(10, 6))
Dobs = survey.dobs.reshape((len(rx.times), len(x)))
Dpred = invProb.dpred.reshape((len(rx.times), len(x)))
for i in range(len(x)):
ax[0].loglog(rx.times - t0, -Dobs[:, i].flatten(), 'k')
ax[0].loglog(rx.times - t0, -Dpred[:, i].flatten(), 'k.')
if i == 0:
ax[0].legend(('$d^{obs}$', '$d^{pred}$'), fontsize=16)
ax[0].set_xlabel('Time (s)', fontsize=14)
ax[0].set_ylabel('$db_z / dt$ (nT/s)', fontsize=16)
ax[0].set_xlabel('Time (s)', fontsize=14)
ax[0].grid(color='k', alpha=0.5, linestyle='dashed', linewidth=0.5)
plt.semilogx(sigma[active], mesh.vectorCCz[active])
plt.semilogx(np.exp(mopt), mesh.vectorCCz[active])
ax[1].set_ylim(-600, 0)
ax[1].set_xlim(1e-4, 1e-1)
ax[1].set_xlabel('Conductivity (S/m)', fontsize=14)
ax[1].set_ylabel('Depth (m)', fontsize=14)
ax[1].grid(color='k', alpha=0.5, linestyle='dashed', linewidth=0.5)
plt.legend(['$\sigma_{true}$', '$\sigma_{pred}$'])
def run(plotIt=True, saveFig=False, cleanup=True):
"""
Run 1D inversions for a single sounding of the RESOLVE and SkyTEM
bookpurnong data
:param bool plotIt: show the plots?
:param bool saveFig: save the figure
:param bool cleanup: remove the downloaded results
"""
downloads, directory = download_and_unzip_data()
resolve = h5py.File(
os.path.sep.join([directory, "booky_resolve.hdf5"]),
"r"
)
skytem = h5py.File(
os.path.sep.join([directory, "booky_skytem.hdf5"]),
"r"
)
river_path = resolve["river_path"].value
# Choose a sounding location to invert
xloc, yloc = 462100.0, 6196500.0
rxind_skytem = np.argmin(
abs(skytem["xy"][:, 0]-xloc)+abs(skytem["xy"][:, 1]-yloc)
)
rxind_resolve = np.argmin(
abs(resolve["xy"][:, 0]-xloc)+abs(resolve["xy"][:, 1]-yloc)
)
# Plot both resolve and skytem data on 2D plane
fig = plt.figure(figsize=(13, 6))
title = ["RESOLVE In-phase 400 Hz", "SkyTEM High moment 156 $\mu$s"]
ax1 = plt.subplot(121)
ax2 = plt.subplot(122)
axs = [ax1, ax2]
out_re = Utils.plot2Ddata(
resolve["xy"], resolve["data"][:, 0], ncontour=100,
contourOpts={"cmap": "viridis"}, ax=ax1
)
vmin, vmax = out_re[0].get_clim()
cb_re = plt.colorbar(
out_re[0], ticks=np.linspace(vmin, vmax, 3), ax=ax1,
fraction=0.046, pad=0.04
)
temp_skytem = skytem["data"][:, 5].copy()
temp_skytem[skytem["data"][:, 5] > 7e-10] = 7e-10
out_sky = Utils.plot2Ddata(
skytem["xy"][:, :2], temp_skytem, ncontour=100,
contourOpts={"cmap": "viridis", "vmax": 7e-10}, ax=ax2
)
vmin, vmax = out_sky[0].get_clim()
cb_sky = plt.colorbar(
out_sky[0], ticks=np.linspace(vmin, vmax*0.99, 3), ax=ax2,
format="%.1e", fraction=0.046, pad=0.04
)
cb_re.set_label("Bz (ppm)")
cb_sky.set_label("dB$_z$ / dt (V/A-m$^4$)")
for i, ax in enumerate(axs):
xticks = [460000, 463000]
yticks = [6195000, 6198000, 6201000]
ax.set_xticks(xticks)
ax.set_yticks(yticks)
ax.plot(xloc, yloc, 'wo')
ax.plot(river_path[:, 0], river_path[:, 1], 'k', lw=0.5)
ax.set_aspect("equal")
if i == 1:
ax.plot(
skytem["xy"][:, 0], skytem["xy"][:, 1], 'k.',
alpha=0.02, ms=1
)
ax.set_yticklabels([str(" ") for f in yticks])
else:
ax.plot(
resolve["xy"][:, 0], resolve["xy"][:, 1], 'k.', alpha=0.02,
ms=1
)
ax.set_yticklabels([str(f) for f in yticks])
ax.set_ylabel("Northing (m)")
ax.set_xlabel("Easting (m)")
ax.set_title(title[i])
ax.axis('equal')
# plt.tight_layout()
if saveFig is True:
fig.savefig("resolve_skytem_data.png", dpi=600)
# ------------------ Mesh ------------------ #
# Step1: Set 2D cylindrical mesh
cs, ncx, ncz, npad = 1., 10., 10., 20
hx = [(cs, ncx), (cs, npad, 1.3)]
npad = 12
temp = np.logspace(np.log10(1.), np.log10(12.), 19)
temp_pad = temp[-1] * 1.3 ** np.arange(npad)
hz = np.r_[temp_pad[::-1], temp[::-1], temp, temp_pad]
mesh = Mesh.CylMesh([hx, 1, hz], '00C')
active = mesh.vectorCCz < 0.
# Step2: Set a SurjectVertical1D mapping
# Note: this sets our inversion model as 1D log conductivity
# below subsurface
active = mesh.vectorCCz < 0.
actMap = Maps.InjectActiveCells(mesh, active, np.log(1e-8), nC=mesh.nCz)
mapping = Maps.ExpMap(mesh) * Maps.SurjectVertical1D(mesh) * actMap
sig_half = 1e-1
sig_air = 1e-8
sigma = np.ones(mesh.nCz)*sig_air
sigma[active] = sig_half
# Initial and reference model
m0 = np.log(sigma[active])
# ------------------ RESOLVE Forward Simulation ------------------ #
# Step3: Invert Resolve data
# Bird height from the surface
b_height_resolve = resolve["src_elevation"].value
src_height_resolve = b_height_resolve[rxind_resolve]
# Set Rx (In-phase and Quadrature)
rxOffset = 7.86
bzr = EM.FDEM.Rx.Point_bSecondary(
np.array([[rxOffset, 0., src_height_resolve]]),
orientation='z',
component='real'
)
bzi = EM.FDEM.Rx.Point_b(
np.array([[rxOffset, 0., src_height_resolve]]),
orientation='z',
component='imag'
)
# Set Source (In-phase and Quadrature)
frequency_cp = resolve["frequency_cp"].value
freqs = frequency_cp.copy()
srcLoc = np.array([0., 0., src_height_resolve])
srcList = [EM.FDEM.Src.MagDipole([bzr, bzi], freq, srcLoc, orientation='Z')
for freq in freqs]
# Set FDEM survey (In-phase and Quadrature)
survey = EM.FDEM.Survey(srcList)
prb = EM.FDEM.Problem3D_b(mesh, sigmaMap=mapping, Solver=Solver)
prb.pair(survey)
# ------------------ RESOLVE Inversion ------------------ #
# Primary field
bp = - mu_0/(4*np.pi*rxOffset**3)
# Observed data
cpi_inds = [0, 2, 6, 8, 10]
cpq_inds = [1, 3, 7, 9, 11]
dobs_re = np.c_[
resolve["data"][rxind_resolve, :][cpi_inds],
resolve["data"][rxind_resolve, :][cpq_inds]
].flatten() * bp * 1e-6
# Uncertainty
std = np.repeat(np.r_[np.ones(3)*0.1, np.ones(2)*0.15], 2)
floor = 20 * abs(bp) * 1e-6
uncert = abs(dobs_re) * std + floor
# Data Misfit
survey.dobs = dobs_re
dmisfit = DataMisfit.l2_DataMisfit(survey)
dmisfit.W = 1./uncert
# Regularization
regMesh = Mesh.TensorMesh([mesh.hz[mapping.maps[-1].indActive]])
reg = Regularization.Simple(regMesh)
# Optimization
opt = Optimization.InexactGaussNewton(maxIter=5)
# statement of the inverse problem
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
# Inversion directives and parameters
target = Directives.TargetMisfit() # stop when we hit target misfit
invProb.beta = 2.
# betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1e0)
inv = Inversion.BaseInversion(invProb, directiveList=[target])
reg.alpha_s = 1e-3
reg.alpha_x = 1.
reg.mref = m0.copy()
opt.LSshorten = 0.5
opt.remember('xc')
# run the inversion
mopt_re = inv.run(m0)
dpred_re = invProb.dpred
# ------------------ SkyTEM Forward Simulation ------------------ #
# Step4: Invert SkyTEM data
# Bird height from the surface
b_height_skytem = skytem["src_elevation"].value
src_height = b_height_skytem[rxind_skytem]
srcLoc = np.array([[0., 0., src_height]])
# Radius of the source loop
area = skytem["area"].value
radius = np.sqrt(area/np.pi)
rxLoc = np.array([[radius, 0., src_height]])
# Parameters for current waveform
t0 = skytem["t0"].value
times = skytem["times"].value
waveform_skytem = skytem["waveform"].value
offTime = t0
times_off = times - t0
# Note: we are Using theoretical VTEM waveform,
# but effectively fits SkyTEM waveform
peakTime = 1.0000000e-02
a = 3.
dbdt_z = EM.TDEM.Rx.Point_dbdt(
locs=rxLoc, times=times_off[:-3]+offTime, orientation='z'
) # vertical db_dt
rxList = [dbdt_z] # list of receivers
srcList = [
EM.TDEM.Src.CircularLoop(
rxList, loc=srcLoc, radius=radius,
orientation='z',
waveform=EM.TDEM.Src.VTEMWaveform(
offTime=offTime, peakTime=peakTime, a=3.
)
)
]
# solve the problem at these times
timeSteps = [
(peakTime/5, 5), ((offTime-peakTime)/5, 5),
(1e-5, 5), (5e-5, 5), (1e-4, 10), (5e-4, 15)
]
prob = EM.TDEM.Problem3D_e(
mesh, timeSteps=timeSteps, sigmaMap=mapping, Solver=Solver
)
survey = EM.TDEM.Survey(srcList)
prob.pair(survey)
src = srcList[0]
rx = src.rxList[0]
wave = []
for time in prob.times:
wave.append(src.waveform.eval(time))
wave = np.hstack(wave)
out = survey.dpred(m0)
# plot the waveform
fig = plt.figure(figsize=(5, 3))
times_off = times-t0
plt.plot(waveform_skytem[:, 0], waveform_skytem[:, 1], 'k.')
plt.plot(prob.times, wave, 'k-', lw=2)
plt.legend(("SkyTEM waveform", "Waveform (fit)"), fontsize=10)
for t in rx.times:
plt.plot(np.ones(2)*t, np.r_[-0.03, 0.03], 'k-')
plt.ylim(-0.1, 1.1)
plt.grid(True)
plt.xlabel("Time (s)")
plt.ylabel("Normalized current")
if saveFig:
fig.savefig("skytem_waveform", dpi=200)
# Observed data
dobs_sky = skytem["data"][rxind_skytem, :-3] * area
# ------------------ SkyTEM Inversion ------------------ #
# Uncertainty
std = 0.12
floor = 7.5e-12
uncert = abs(dobs_sky) * std + floor
# Data Misfit
survey.dobs = -dobs_sky
dmisfit = DataMisfit.l2_DataMisfit(survey)
uncert = 0.12*abs(dobs_sky) + 7.5e-12
dmisfit.W = Utils.sdiag(1./uncert)
# Regularization
regMesh = Mesh.TensorMesh([mesh.hz[mapping.maps[-1].indActive]])
reg = Regularization.Simple(regMesh)
# Optimization
opt = Optimization.InexactGaussNewton(maxIter=5)
# statement of the inverse problem
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
# Directives and Inversion Parameters
target = Directives.TargetMisfit()
# betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1e0)
invProb.beta = 20.
inv = Inversion.BaseInversion(invProb, directiveList=[target])
reg.alpha_s = 1e-1
reg.alpha_x = 1.
opt.LSshorten = 0.5
opt.remember('xc')
reg.mref = mopt_re # Use RESOLVE model as a reference model
# run the inversion
mopt_sky = inv.run(m0)
dpred_sky = invProb.dpred
# Plot the figure from the paper
plt.figure(figsize=(12, 8))
fs = 13 # fontsize
matplotlib.rcParams['font.size'] = fs
ax0 = plt.subplot2grid((2, 2), (0, 0), rowspan=2)
ax1 = plt.subplot2grid((2, 2), (0, 1))
ax2 = plt.subplot2grid((2, 2), (1, 1))
# Recovered Models
sigma_re = np.repeat(np.exp(mopt_re), 2, axis=0)
sigma_sky = np.repeat(np.exp(mopt_sky), 2, axis=0)
z = np.repeat(mesh.vectorCCz[active][1:], 2, axis=0)
z = np.r_[mesh.vectorCCz[active][0], z, mesh.vectorCCz[active][-1]]
ax0.semilogx(sigma_re, z, 'k', lw=2, label="RESOLVE")
ax0.semilogx(sigma_sky, z, 'b', lw=2, label="SkyTEM")
ax0.set_ylim(-50, 0)
# ax0.set_xlim(5e-4, 1e2)
ax0.grid(True)
ax0.set_ylabel("Depth (m)")
ax0.set_xlabel("Conducivity (S/m)")
ax0.legend(loc=3)
ax0.set_title("(a) Recovered Models")
# RESOLVE Data
ax1.loglog(
frequency_cp, dobs_re.reshape((5, 2))[:, 0]/bp*1e6, 'k-',
label="Obs (real)"
)
ax1.loglog(
frequency_cp, dobs_re.reshape((5, 2))[:, 1]/bp*1e6, 'k--',
label="Obs (imag)"
)
ax1.loglog(
frequency_cp, dpred_re.reshape((5, 2))[:, 0]/bp*1e6, 'k+', ms=10,
markeredgewidth=2., label="Pred (real)"
)
ax1.loglog(
frequency_cp, dpred_re.reshape((5, 2))[:, 1]/bp*1e6, 'ko', ms=6,
markeredgecolor='k', markeredgewidth=0.5, label="Pred (imag)"
)
ax1.set_title("(b) RESOLVE")
ax1.set_xlabel("Frequency (Hz)")
ax1.set_ylabel("Bz (ppm)")
ax1.grid(True)
ax1.legend(loc=3, fontsize=11)
# SkyTEM data
ax2.loglog(times_off[3:]*1e6, dobs_sky/area, 'b-', label="Obs")
ax2.loglog(
times_off[3:]*1e6, -dpred_sky/area, 'bo', ms=4,
markeredgecolor='k', markeredgewidth=0.5, label="Pred"
)
ax2.set_xlim(times_off.min()*1e6*1.2, times_off.max()*1e6*1.1)
ax2.set_xlabel("Time ($\mu s$)")
ax2.set_ylabel("dBz / dt (V/A-m$^4$)")
ax2.set_title("(c) SkyTEM High-moment")
ax2.grid(True)
ax2.legend(loc=3)
a3 = plt.axes([0.86, .33, .1, .09], facecolor=[0.8, 0.8, 0.8, 0.6])
a3.plot(prob.times*1e6, wave, 'k-')
a3.plot(
rx.times*1e6, np.zeros_like(rx.times), 'k|', markeredgewidth=1,
markersize=12
)
a3.set_xlim([prob.times.min()*1e6*0.75, prob.times.max()*1e6*1.1])
a3.set_title('(d) Waveform', fontsize=11)
a3.set_xticks([prob.times.min()*1e6, t0*1e6, prob.times.max()*1e6])
a3.set_yticks([])
# a3.set_xticklabels(['0', '2e4'])
a3.set_xticklabels(['-1e4', '0', '1e4'])
plt.tight_layout()
if saveFig:
plt.savefig("booky1D_time_freq.png", dpi=600)
if plotIt:
plt.show()
if cleanup:
print( os.path.split(directory)[:-1])
os.remove(
os.path.sep.join(
directory.split()[:-1] + ["._bookpurnong_inversion"]
)
)
os.remove(downloads)
shutil.rmtree(directory)
def run_inversion(
m0, survey, actind, mesh,
std, eps,
maxIter=15, beta0_ratio=1e0,
coolingFactor=5, coolingRate=2,
upper=np.inf, lower=-np.inf,
use_sensitivity_weight=False,
alpha_s=1e-4,
alpha_x=1.,
alpha_y=1.,
alpha_z=1.,
):
"""
Run IP inversion
"""
dmisfit = DataMisfit.l2_DataMisfit(survey)
uncert = abs(survey.dobs) * std + eps
dmisfit.W = 1./uncert
# Map for a regularization
regmap = Maps.IdentityMap(nP=int(actind.sum()))
# Related to inversion
if use_sensitivity_weight:
reg = Regularization.Sparse(
mesh, indActive=actind, mapping=regmap
)
reg.alpha_s = alpha_s
reg.alpha_x = alpha_x
reg.alpha_y = alpha_y
reg.alpha_z = alpha_z
else:
reg = Regularization.Sparse(
mesh, indActive=actind, mapping=regmap,
cell_weights=mesh.vol[actind]
)
reg.alpha_s = alpha_s
reg.alpha_x = alpha_x
reg.alpha_y = alpha_y
reg.alpha_z = alpha_z
opt = Optimization.ProjectedGNCG(maxIter=maxIter, upper=upper, lower=lower)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
beta = Directives.BetaSchedule(
coolingFactor=coolingFactor, coolingRate=coolingRate
)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=beta0_ratio)
target = Directives.TargetMisfit()
# Need to have basice saving function
if use_sensitivity_weight:
updateSensW = Directives.UpdateSensitivityWeights()
update_Jacobi = Directives.UpdatePreconditioner()
directiveList = [
beta, betaest, target, update_Jacobi
]
else:
directiveList = [
beta, betaest, target
]
inv = Inversion.BaseInversion(
invProb, directiveList=directiveList
)
opt.LSshorten = 0.5
opt.remember('xc')
# Run inversion
mopt = inv.run(m0)
return mopt, invProb.dpred
opt = Optimization.ProjectedGNCG(maxIter=25,
lower=-np.inf,
upper=np.inf,
maxIterLS=20,
maxIterCG=30,
tolCG=1e-3)
# Create the default L2 inverse problem from the above objects
invProb = InvProblem.BaseInvProblem(ComboMisfit, reg, opt)
# Specify how the initial beta is found
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1)
# Target misfit to stop the inversion,
# try to fit as much as possible of the signal, we don't want to lose anything
targetMisfit = Directives.TargetMisfit(chifact=targetChi)
# Pre-conditioner
update_Jacobi = Directives.UpdatePreconditioner()
IRLS = Directives.Update_IRLS(f_min_change=1e-3,
minGNiter=1,
beta_tol=0.25,
maxIRLSiter=1,
chifact_target=targetChi)
# Save model
saveIt = Directives.SaveUBCModelEveryIteration(mapping=activeCellsMap,
fileName=workDir + dsep +
outDir + driver["dataFile"][0])
# Put all the parts together
def run(plotIt=True, survey_type="dipole-dipole", p=0., qx=2., qz=2.):
np.random.seed(1)
# Initiate I/O class for DC
IO = DC.IO()
# Obtain ABMN locations
xmin, xmax = 0., 200.
ymin, ymax = 0., 0.
zmin, zmax = 0, 0
endl = np.array([[xmin, ymin, zmin], [xmax, ymax, zmax]])
# Generate DC survey object
survey = DC.Utils.gen_DCIPsurvey(endl,
survey_type=survey_type,
dim=2,
a=10,
b=10,
n=10)
survey.getABMN_locations()
survey = IO.from_ambn_locations_to_survey(survey.a_locations,
survey.b_locations,
survey.m_locations,
survey.n_locations,
survey_type,
data_dc_type='volt')
# Obtain 2D TensorMesh
mesh, actind = IO.set_mesh()
topo, mesh1D = DC.Utils.genTopography(mesh, -10, 0, its=100)
actind = Utils.surface2ind_topo(mesh, np.c_[mesh1D.vectorCCx, topo])
survey.drapeTopo(mesh, actind, option="top")
# Build a conductivity model
blk_inds_c = Utils.ModelBuilder.getIndicesSphere(np.r_[60., -25.], 12.5,
mesh.gridCC)
blk_inds_r = Utils.ModelBuilder.getIndicesSphere(np.r_[140., -25.], 12.5,
mesh.gridCC)
layer_inds = mesh.gridCC[:, 1] > -5.
sigma = np.ones(mesh.nC) * 1. / 100.
sigma[blk_inds_c] = 1. / 10.
sigma[blk_inds_r] = 1. / 1000.
sigma[~actind] = 1. / 1e8
rho = 1. / sigma
# Show the true conductivity model
if plotIt:
fig = plt.figure(figsize=(12, 3))
ax = plt.subplot(111)
temp = rho.copy()
temp[~actind] = np.nan
out = mesh.plotImage(temp,
grid=True,
ax=ax,
gridOpts={'alpha': 0.2},
clim=(10, 1000),
pcolorOpts={
"cmap": "viridis",
"norm": colors.LogNorm()
})
ax.plot(survey.electrode_locations[:, 0],
survey.electrode_locations[:, 1], 'k.')
ax.set_xlim(IO.grids[:, 0].min(), IO.grids[:, 0].max())
ax.set_ylim(-IO.grids[:, 1].max(), IO.grids[:, 1].min())
cb = plt.colorbar(out[0])
cb.set_label("Resistivity (ohm-m)")
ax.set_aspect('equal')
plt.show()
# Use Exponential Map: m = log(rho)
actmap = Maps.InjectActiveCells(mesh,
indActive=actind,
valInactive=np.log(1e8))
mapping = Maps.ExpMap(mesh) * actmap
# Generate mtrue
mtrue = np.log(rho[actind])
# Generate 2.5D DC problem
# "N" means potential is defined at nodes
prb = DC.Problem2D_N(mesh,
rhoMap=mapping,
storeJ=True,
Solver=Solver,
verbose=True)
# Pair problem with survey
try:
prb.pair(survey)
except:
survey.unpair()
prb.pair(survey)
# Make synthetic DC data with 5% Gaussian noise
dtrue = survey.makeSyntheticData(mtrue, std=0.05, force=True)
IO.data_dc = dtrue
# Show apparent resisitivty pseudo-section
if plotIt:
IO.plotPseudoSection(data=survey.dobs / IO.G,
data_type='apparent_resistivity')
# Show apparent resisitivty histogram
if plotIt:
fig = plt.figure()
out = hist(survey.dobs / IO.G, bins=20)
plt.xlabel("Apparent Resisitivty ($\Omega$m)")
plt.show()
# Set initial model based upon histogram
m0 = np.ones(actmap.nP) * np.log(100.)
# Set uncertainty
# floor
eps = 10**(-3.2)
# percentage
std = 0.05
dmisfit = DataMisfit.l2_DataMisfit(survey)
uncert = abs(survey.dobs) * std + eps
dmisfit.W = 1. / uncert
# Map for a regularization
regmap = Maps.IdentityMap(nP=int(actind.sum()))
# Related to inversion
reg = Regularization.Sparse(mesh,
indActive=actind,
mapping=regmap,
gradientType='components')
# gradientType = 'components'
reg.norms = np.c_[p, qx, qz, 0.]
IRLS = Directives.Update_IRLS(maxIRLSiter=20,
minGNiter=1,
betaSearch=False,
fix_Jmatrix=True)
opt = Optimization.InexactGaussNewton(maxIter=40)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
beta = Directives.BetaSchedule(coolingFactor=5, coolingRate=2)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1e0)
target = Directives.TargetMisfit()
update_Jacobi = Directives.UpdatePreconditioner()
inv = Inversion.BaseInversion(invProb, directiveList=[betaest, IRLS])
prb.counter = opt.counter = Utils.Counter()
opt.LSshorten = 0.5
opt.remember('xc')
# Run inversion
mopt = inv.run(m0)
rho_est = mapping * mopt
rho_est_l2 = mapping * invProb.l2model
rho_est[~actind] = np.nan
rho_est_l2[~actind] = np.nan
rho_true = rho.copy()
rho_true[~actind] = np.nan
# show recovered conductivity
if plotIt:
vmin, vmax = rho.min(), rho.max()
fig, ax = plt.subplots(3, 1, figsize=(20, 9))
out1 = mesh.plotImage(rho_true,
clim=(10, 1000),
pcolorOpts={
"cmap": "viridis",
"norm": colors.LogNorm()
},
ax=ax[0])
out2 = mesh.plotImage(rho_est_l2,
clim=(10, 1000),
pcolorOpts={
"cmap": "viridis",
"norm": colors.LogNorm()
},
ax=ax[1])
out3 = mesh.plotImage(rho_est,
clim=(10, 1000),
pcolorOpts={
"cmap": "viridis",
"norm": colors.LogNorm()
},
ax=ax[2])
out = [out1, out2, out3]
titles = ["True", "L2", ("L%d, Lx%d, Lz%d") % (p, qx, qz)]
for i in range(3):
ax[i].plot(survey.electrode_locations[:, 0],
survey.electrode_locations[:, 1], 'kv')
ax[i].set_xlim(IO.grids[:, 0].min(), IO.grids[:, 0].max())
ax[i].set_ylim(-IO.grids[:, 1].max(), IO.grids[:, 1].min())
cb = plt.colorbar(out[i][0], ax=ax[i])
cb.set_label("Resistivity ($\Omega$m)")
ax[i].set_xlabel("Northing (m)")
ax[i].set_ylabel("Elevation (m)")
ax[i].set_aspect('equal')
ax[i].set_title(titles[i])
plt.tight_layout()
plt.show()
def run_inversion(
self,
maxIter=60,
m0=0.0,
mref=0.0,
percentage=5,
floor=0.1,
chifact=1,
beta0_ratio=1.0,
coolingFactor=1,
n_iter_per_beta=1,
alpha_s=1.0,
alpha_x=1.0,
alpha_z=1.0,
use_target=False,
use_tikhonov=True,
use_irls=False,
p_s=2,
p_x=2,
p_y=2,
p_z=2,
beta_start=None,
):
self.uncertainty = percentage * abs(self.survey.dobs) * 0.01 + floor
m0 = np.ones(self.mesh.nC) * m0
mref = np.ones(self.mesh.nC) * mref
if ~use_tikhonov:
reg = Regularization.Sparse(
self.mesh,
alpha_s=alpha_s,
alpha_x=alpha_x,
alpha_y=alpha_z,
mref=mref,
mapping=Maps.IdentityMap(self.mesh),
cell_weights=self.mesh.vol,
)
else:
reg = Regularization.Tikhonov(
self.mesh,
alpha_s=alpha_s,
alpha_x=alpha_x,
alpha_y=alpha_z,
mref=mref,
mapping=Maps.IdentityMap(self.mesh),
)
dmis = DataMisfit.l2_DataMisfit(self.survey)
dmis.W = 1.0 / self.uncertainty
opt = Optimization.ProjectedGNCG(maxIter=maxIter, maxIterCG=20)
opt.lower = 0.0
opt.remember("xc")
opt.tolG = 1e-10
opt.eps = 1e-10
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
save = Directives.SaveOutputEveryIteration()
beta_schedule = Directives.BetaSchedule(coolingFactor=coolingFactor,
coolingRate=n_iter_per_beta)
if use_irls:
IRLS = Directives.Update_IRLS(
f_min_change=1e-4,
minGNiter=1,
silent=False,
maxIRLSiter=40,
beta_tol=5e-1,
coolEpsFact=1.3,
chifact_start=chifact,
)
if beta_start is None:
directives = [
Directives.BetaEstimate_ByEig(beta0_ratio=beta0_ratio),
IRLS,
save,
]
else:
directives = [IRLS, save]
invProb.beta = beta_start
reg.norms = np.c_[p_s, p_x, p_z, 2]
else:
target = Directives.TargetMisfit(chifact=chifact)
directives = [
Directives.BetaEstimate_ByEig(beta0_ratio=beta0_ratio),
beta_schedule,
save,
]
if use_target:
directives.append(target)
inv = Inversion.BaseInversion(invProb, directiveList=directives)
mopt = inv.run(m0)
model = opt.recall("xc")
model.append(mopt)
pred = []
for m in model:
pred.append(self.survey.dpred(m))
return model, pred, save
indActive=actind,
alpha_s=1e-6,
alpha_x=1.,
alpha_y=1.,
alpha_z=1.)
# Optimization Scheme
opt = Optimization.InexactGaussNewton(maxIter=10)
# Form the problem
opt.remember('xc')
invProb = InvProblem.BaseInvProblem(dmis, regT, opt)
# Directives for Inversions
beta = Directives.BetaEstimate_ByEig(beta0_ratio=1e+1)
Target = Directives.TargetMisfit()
betaSched = Directives.BetaSchedule(coolingFactor=5., coolingRate=2)
inv = Inversion.BaseInversion(invProb, directiveList=[beta, Target, betaSched])
# Run Inversion
minv = inv.run(m0)
# Final Plot
############
fig, ax = plt.subplots(2, 2, figsize=(12, 6))
ax = Utils.mkvc(ax)
cyl0v = getCylinderPoints(x0, z0, r0)
cyl1v = getCylinderPoints(x1, z1, r1)
def fitWithStretchedExponetial(time, survey_ip, sources, Rho, start_time=None):
if start_time is None:
start_time = 0
# Choose all time channels
tinds = time > start_time
nLoc = survey_ip.dobs.T[tinds, :].shape[1]
# Setup wire for different properties
wires = Maps.Wires(('eta', nLoc), ('tau', nLoc), ('c', nLoc))
taumap = Maps.ExpMap(nP=nLoc) * wires.tau
etamap = Maps.ExpMap(nP=nLoc) * wires.eta
cmap = Maps.ExpMap(nP=nLoc) * wires.c
# This is almost dummmy mesh and xyz loc at the moment
# But, there is potential use later
m1D = Mesh.TensorMesh([np.ones(nLoc)])
# # Set survey
survey = SEMultiSurvey(time[tinds] * 1e-3, sources[:, :], n_pulse=2, T=4)
survey.dobs = (survey_ip.dobs.T[tinds, :]).flatten(order='F')
# Set problem
prob = SEMultiInvProblem(m1D, etaMap=etamap, tauMap=taumap, cMap=cmap)
prob.pair(survey)
# Set initial model
eta0, tau0, c0 = abs(
survey_ip.dobs.T[0, :].T), 1. * np.ones(nLoc), 1. * np.ones(nLoc)
m0 = np.r_[np.log(eta0), np.log(tau0), np.log(c0)]
std = 0.02
plt.plot(survey.dpred(m0))
plt.plot(survey.dobs, '.')
plt.title("Obs & pred")
plt.xlabel("data point")
plt.ylabel("value")
plt.show()
mreg = Mesh.TensorMesh([len(m0)])
dmisfit = DataMisfit.l2_DataMisfit(survey)
uncert = (abs(survey.dobs) * std + 0.01) * 1.1
dmisfit.W = 1. / uncert
reg = Regularization.Simple(mreg)
opt = Optimization.ProjectedGNCG(maxIter=20)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
# Create an inversion object
target = Directives.TargetMisfit()
invProb.beta = 0.
inv = Inversion.BaseInversion(invProb, directiveList=[target])
# reg.mref = 0.*m0
prob.counter = opt.counter = Utils.Counter()
opt.LSshorten = 0.5
opt.remember('xc')
opt.tolX = 1e-20
opt.tolF = 1e-20
opt.tolG = 1e-20
opt.eps = 1e-20
m_upper = np.r_[np.ones_like(tau0) * np.log(200),
np.ones_like(tau0) * np.log(10.),
np.ones_like(tau0) * np.log(1.)]
m_lower = np.r_[np.ones_like(tau0) * np.log(1),
np.ones_like(tau0) * np.log(1e-2),
np.ones_like(tau0) * np.log(0.1)]
opt.lower = m_lower
opt.upper = m_upper
mopt = inv.run(m0)
eta = etamap * mopt
tau = taumap * mopt
c = cmap * mopt
DPRED = invProb.dpred.reshape((nLoc, time[tinds].size))
DOBS = survey.dobs.reshape((nLoc, time[tinds].size))
UNCERT = uncert.reshape((nLoc, time[tinds].size))
error = ((eta * 1e-3) /
np.sqrt(np.sum((DOBS - DPRED)**2, axis=1) / time[tinds].size))
from matplotlib import colors
fig = plt.figure(figsize=(6, 5))
active_inds = (Rho[:, 0] > 10.) & (Rho[:, 0] < 1e3) & (abs(
(DPRED - DOBS) / UNCERT).sum(axis=1) / time[tinds].size < 1.)
out = plt.scatter(tau[active_inds],
c[active_inds],
c=eta[active_inds],
norm=colors.LogNorm(),
cmap="magma",
s=2)
cb = plt.colorbar(out)
plt.xscale('log')
plt.yscale('log')
plt.xlabel("Tau")
plt.ylabel("c")
cb.set_label("Eta (mV/V)")
plt.show()
inds = (abs((DPRED - DOBS) / UNCERT).sum(axis=1) / time[tinds].size < 20.)
# print(inds)
inds = np.arange(survey.n_location)[inds]
out = plt.loglog(time[tinds], DPRED[inds[::2], :].T, 'r')
out = plt.loglog(time[tinds], DOBS[inds[::2], :].T, 'kx')
print(np.sum((DPRED - DOBS)**2) / time.size)
fig, axs = plt.subplots(4, 1)
properties = [
Rho[:, 0][active_inds], eta[active_inds], tau[active_inds],
c[active_inds]
]
titles = ["$\\rho_{a}$", "$\\eta_{a}$", "$\\tau_{a}$", "$c_{a}$"]
colors = ['#1f77b4', 'seagreen', 'crimson', 'gold']
for i, ax in enumerate(axs):
out = ax.hist(np.log10(properties[i]), bins=50, color=colors[i])
ax.set_title(titles[i])
ax.set_xticklabels([("%.1f") % (10**tick) for tick in ax.get_xticks()])
plt.tight_layout()
plt.show()
return eta, tau, c, error
def resolve_1Dinversions(mesh,
dobs,
src_height,
freqs,
m0,
mref,
mapping,
std=0.08,
floor=1e-14,
rxOffset=7.86):
"""
Perform a single 1D inversion for a RESOLVE sounding for Horizontal
Coplanar Coil data (both real and imaginary).
:param discretize.CylMesh mesh: mesh used for the forward simulation
:param numpy.array dobs: observed data
:param float src_height: height of the source above the ground
:param numpy.array freqs: frequencies
:param numpy.array m0: starting model
:param numpy.array mref: reference model
:param Maps.IdentityMap mapping: mapping that maps the model to electrical conductivity
:param float std: percent error used to construct the data misfit term
:param float floor: noise floor used to construct the data misfit term
:param float rxOffset: offset between source and receiver.
"""
# ------------------- Forward Simulation ------------------- #
# set up the receivers
bzr = EM.FDEM.Rx.Point_bSecondary(np.array([[rxOffset, 0., src_height]]),
orientation='z',
component='real')
bzi = EM.FDEM.Rx.Point_b(np.array([[rxOffset, 0., src_height]]),
orientation='z',
component='imag')
# source location
srcLoc = np.array([0., 0., src_height])
srcList = [
EM.FDEM.Src.MagDipole([bzr, bzi], freq, srcLoc, orientation='Z')
for freq in freqs
]
# construct a forward simulation
survey = EM.FDEM.Survey(srcList)
prb = EM.FDEM.Problem3D_b(mesh, sigmaMap=mapping, Solver=PardisoSolver)
prb.pair(survey)
# ------------------- Inversion ------------------- #
# data misfit term
survey.dobs = dobs
dmisfit = DataMisfit.l2_DataMisfit(survey)
uncert = abs(dobs) * std + floor
dmisfit.W = 1. / uncert
# regularization
regMesh = Mesh.TensorMesh([mesh.hz[mapping.maps[-1].indActive]])
reg = Regularization.Simple(regMesh)
reg.mref = mref
# optimization
opt = Optimization.InexactGaussNewton(maxIter=10)
# statement of the inverse problem
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
# Inversion directives and parameters
target = Directives.TargetMisfit()
inv = Inversion.BaseInversion(invProb, directiveList=[target])
invProb.beta = 2. # Fix beta in the nonlinear iterations
reg.alpha_s = 1e-3
reg.alpha_x = 1.
prb.counter = opt.counter = Utils.Counter()
opt.LSshorten = 0.5
opt.remember('xc')
# run the inversion
mopt = inv.run(m0)
return mopt, invProb.dpred, survey.dobs
def run(plotIt=True):
"""
FLOW: Richards: 1D: Inversion
=============================
The example shows an inversion of Richards equation in 1D with a
heterogeneous hydraulic conductivity function.
The haverkamp model is used with the same parameters as Celia1990_
the boundary and initial conditions are also the same. The simulation
domain is 40cm deep and is run for an hour with an exponentially
increasing time step that has a maximum of one minute. The general
setup of the experiment is an infiltration front that advances
downward through the model over time.
The model chosen is the saturated hydraulic conductivity inside
the hydraulic conductivity function (using haverkamp). The initial
model is chosen to be the background (1e-3 cm/s). The saturation data
has 2% random Gaussian noise added.
The figure shows the recovered saturated hydraulic conductivity
next to the true model. The other two figures show the saturation
field for the entire simulation for the true and recovered models.
Rowan Cockett - 21/12/2016
.. _Celia1990: http://www.webpages.uidaho.edu/ch/papers/Celia.pdf
"""
M = Mesh.TensorMesh([np.ones(40)], x0='N')
M.setCellGradBC('dirichlet')
# We will use the haverkamp empirical model with parameters from Celia1990
k_fun, theta_fun = Richards.Empirical.haverkamp(M,
A=1.1750e+06,
gamma=4.74,
alpha=1.6110e+06,
theta_s=0.287,
theta_r=0.075,
beta=3.96)
# Here we are making saturated hydraulic conductivity
# an exponential mapping to the model (defined below)
k_fun.KsMap = Maps.ExpMap(nP=M.nC)
# Setup the boundary and initial conditions
bc = np.array([-61.5, -20.7])
h = np.zeros(M.nC) + bc[0]
prob = Richards.RichardsProblem(M,
hydraulic_conductivity=k_fun,
water_retention=theta_fun,
boundary_conditions=bc,
initial_conditions=h,
do_newton=False,
method='mixed',
debug=False)
prob.timeSteps = [(5, 25, 1.1), (60, 40)]
# Create the survey
locs = -np.arange(2, 38, 4.)
times = np.arange(30, prob.timeMesh.vectorCCx[-1], 60)
rxSat = Richards.SaturationRx(locs, times)
survey = Richards.RichardsSurvey([rxSat])
survey.pair(prob)
# Create a simple model for Ks
Ks = 1e-3
mtrue = np.ones(M.nC) * np.log(Ks)
mtrue[15:20] = np.log(5e-2)
mtrue[20:35] = np.log(3e-3)
mtrue[35:40] = np.log(1e-2)
m0 = np.ones(M.nC) * np.log(Ks)
# Create some synthetic data and fields
stdev = 0.02 # The standard deviation for the noise
Hs = prob.fields(mtrue)
survey.makeSyntheticData(mtrue, std=stdev, f=Hs, force=True)
# Setup a pretty standard inversion
reg = Regularization.Tikhonov(M, alpha_s=1e-1)
dmis = DataMisfit.l2_DataMisfit(survey)
opt = Optimization.InexactGaussNewton(maxIter=20, maxIterCG=10)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
beta = Directives.BetaSchedule(coolingFactor=4)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1e2)
target = Directives.TargetMisfit()
dir_list = [beta, betaest, target]
inv = Inversion.BaseInversion(invProb, directiveList=dir_list)
mopt = inv.run(m0)
Hs_opt = prob.fields(mopt)
if plotIt:
plt.figure(figsize=(14, 9))
ax = plt.subplot(121)
plt.semilogx(np.exp(np.c_[mopt, mtrue]), M.gridCC)
plt.xlabel('Saturated Hydraulic Conductivity, $K_s$')
plt.ylabel('Depth, cm')
plt.semilogx([10**-3.9] * len(locs), locs, 'ro')
plt.legend(('$m_{rec}$', '$m_{true}$', 'Data locations'), loc=4)
ax = plt.subplot(222)
mesh2d = Mesh.TensorMesh([prob.timeMesh.hx / 60, prob.mesh.hx], '0N')
sats = [theta_fun(_) for _ in Hs]
clr = mesh2d.plotImage(np.c_[sats][1:, :], ax=ax)
cmap0 = matplotlib.cm.RdYlBu_r
clr[0].set_cmap(cmap0)
c = plt.colorbar(clr[0])
c.set_label('Saturation $\\theta$')
plt.xlabel('Time, minutes')
plt.ylabel('Depth, cm')
plt.title('True saturation over time')
ax = plt.subplot(224)
mesh2d = Mesh.TensorMesh([prob.timeMesh.hx / 60, prob.mesh.hx], '0N')
sats = [theta_fun(_) for _ in Hs_opt]
clr = mesh2d.plotImage(np.c_[sats][1:, :], ax=ax)
cmap0 = matplotlib.cm.RdYlBu_r
clr[0].set_cmap(cmap0)
c = plt.colorbar(clr[0])
c.set_label('Saturation $\\theta$')
plt.xlabel('Time, minutes')
plt.ylabel('Depth, cm')
plt.title('Recovered saturation over time')
plt.tight_layout()
