def test_topo_dpdp(self):
self.survey = utils.gen_DCIPsurvey(
self.endl, "dipole-dipole", dim=2, a=10, b=10, n=10
)
self.survey = self.IO.from_ambn_locations_to_survey(
self.survey.locations_a,
self.survey.locations_b,
self.survey.locations_m,
self.survey.locations_n,
"dipole-dipole",
data_dc_type="apparent_resistivity",
data_dc=np.ones(self.survey.nD) * 100.0,
)
if self.plotIt:
self.IO.plotPseudoSection(data_type="apparent_resistivity")
plt.show()
mesh, actind = self.IO.set_mesh()
topo, mesh1D = utils.genTopography(mesh, -10, 0, its=100)
mesh, actind = self.IO.set_mesh(topo=np.c_[mesh1D.vectorCCx, topo])
self.survey.drape_electrodes_on_topography(mesh, actind, option="top")
if self.plotIt:
mesh.plotImage(actind)
plt.plot(
self.survey.electrode_locations[:, 0],
self.survey.electrode_locations[:, 1],
"k.",
)
plt.show()
def test_flat_dpdp(self):
self.survey = utils.gen_DCIPsurvey(
self.endl, "dipole-dipole", dim=2, a=10, b=10, n=10
)
self.survey = self.IO.from_ambn_locations_to_survey(
self.survey.locations_a,
self.survey.locations_b,
self.survey.locations_m,
self.survey.locations_n,
"dipole-dipole",
data_dc_type="apparent_resistivity",
data_dc=np.ones(self.survey.nD) * 100.0,
)
if self.plotIt:
self.IO.plotPseudoSection(data_type="apparent_resistivity")
plt.show()
mesh, actind = self.IO.set_mesh()
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 = 0.0, 200.0
ymin, ymax = 0.0, 0.0
zmin, zmax = 0, 0
endl = np.array([[xmin, ymin, zmin], [xmax, ymax, zmax]])
# Generate DC survey object
survey = gen_DCIPsurvey(endl,
survey_type=survey_type,
dim=2,
a=10,
b=10,
n=10)
survey = IO.from_ambn_locations_to_survey(
survey.locations_a,
survey.locations_b,
survey.locations_m,
survey.locations_n,
survey_type,
data_dc_type="volt",
)
# Obtain 2D TensorMesh
mesh, actind = IO.set_mesh()
topo, mesh1D = genTopography(mesh, -10, 0, its=100)
actind = utils.surface2ind_topo(mesh, np.c_[mesh1D.vectorCCx, topo])
survey.drape_electrodes_on_topography(mesh, actind, option="top")
# Build a conductivity model
blk_inds_c = utils.model_builder.getIndicesSphere(np.r_[60.0, -25.0], 12.5,
mesh.gridCC)
blk_inds_r = utils.model_builder.getIndicesSphere(np.r_[140.0, -25.0],
12.5, mesh.gridCC)
layer_inds = mesh.gridCC[:, 1] > -5.0
sigma = np.ones(mesh.nC) * 1.0 / 100.0
sigma[blk_inds_c] = 1.0 / 10.0
sigma[blk_inds_r] = 1.0 / 1000.0
sigma[~actind] = 1.0 / 1e8
rho = 1.0 / 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.Simulation2DNodal(mesh,
survey=survey,
rhoMap=mapping,
storeJ=True,
Solver=Solver,
verbose=True)
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
data = prb.make_synthetic_data(mtrue, relative_error=0.05, add_noise=True)
IO.data_dc = data.dobs
# Show apparent resisitivty pseudo-section
if plotIt:
IO.plotPseudoSection(data=data.dobs, data_type="apparent_resistivity")
# Show apparent resisitivty histogram
if plotIt:
fig = plt.figure()
out = hist(data.dobs, bins=20)
plt.xlabel("Apparent Resisitivty ($\Omega$m)")
plt.show()
# Set initial model based upon histogram
m0 = np.ones(actmap.nP) * np.log(100.0)
# Set standard_deviation
# floor (10 ohm-m)
eps = 1.0
# percentage
relative = 0.05
dmisfit = data_misfit.L2DataMisfit(simulation=prb, data=data)
uncert = abs(data.dobs) * relative + eps
dmisfit.standard_deviation = 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 = inverse_problem.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, target, updateSensW, betaest, 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 test_io_rhoa(self):
# Setup a dipole-dipole Survey
for survey_type, test_file, rhoa_file in zip(
["dipole-dipole", "pole-dipole", "dipole-pole", "pole-pole"],
[
"2sph_dipole_dipole.obs",
"2sph_pole_dipole.obs",
"2sph_dipole_pole.obs",
"2sph_pole_pole.obs",
],
[
"rhoA_GIF_dd.txt",
"rhoA_GIF_pd.txt",
"rhoA_GIF_dp.txt",
"rhoA_GIF_pp.txt",
],
):
print("\n Testing {} ... ".format(survey_type))
survey = utils.gen_DCIPsurvey(
self.xyz,
survey_type=survey_type,
dim=self.mesh.dim,
a=self.survey_a,
b=self.survey_b,
n=self.survey_n,
)
self.assertEqual(survey_type, survey.survey_type)
# Setup Problem with exponential mapping
expmap = maps.ExpMap(self.mesh)
problem = dc.Simulation3DCellCentered(
self.mesh, sigmaMap=expmap, survey=survey, bc_type="Neumann"
)
problem.solver = Solver
# Create synthetic data
dobs = problem.make_synthetic_data(self.model, relative_error=0.0)
dobs.eps = 1e-5
# Testing IO
surveyfile = os.path.sep.join([self.basePath, test_file])
utils.writeUBC_DCobs(
surveyfile, dobs, survey_type=survey_type, dim=3, format_type="GENERAL"
)
data2 = utils.readUBC_DC3Dobs(surveyfile)
self.assertTrue(np.allclose(mkvc(data2), mkvc(dobs)))
if self.plotIt:
import matplotlib.pyplot as plt
# Test Pseudosections plotting
fig, ax = plt.subplots(1, 1, figsize=(15, 3))
ax = utils.plot_pseudoSection(
survey,
ax,
survey_type=survey_type,
scale="log",
clim=None,
data_type="appResistivity",
pcolorOpts={"cmap": "viridis"},
data_location=True,
)
plt.show()
# Test the utils functions electrode_separations,
# source_receiver_midpoints, geometric_factor,
# apparent_resistivity all at once
rhoapp = utils.apparent_resistivity(
dobs, survey_type=survey_type, space_type="half-space", eps=0.0
)
rhoA_GIF_file = os.path.sep.join([self.basePath, rhoa_file])
rhoA_GIF = np.loadtxt(rhoA_GIF_file)
passed = np.allclose(rhoapp, rhoA_GIF)
self.assertTrue(passed)
print(" ... ok \n".format(survey_type))
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 = 0.0, 200.0
ymin, ymax = 0.0, 0.0
zmin, zmax = 0, 0
endl = np.array([[xmin, ymin, zmin], [xmax, ymax, zmax]])
# Generate DC survey object
survey_dc = gen_DCIPsurvey(endl,
survey_type=survey_type,
dim=2,
a=10,
b=10,
n=10)
survey_dc = IO.from_abmn_locations_to_survey(
survey_dc.locations_a,
survey_dc.locations_b,
survey_dc.locations_m,
survey_dc.locations_n,
survey_type,
data_dc_type="volt",
data_ip_type="volt",
)
# Obtain 2D TensorMesh
mesh, actind = IO.set_mesh()
topo, mesh1D = genTopography(mesh, -10, 0, its=100)
actind = utils.surface2ind_topo(mesh, np.c_[mesh1D.vectorCCx, topo])
survey_dc.drape_electrodes_on_topography(mesh, actind, option="top")
# Build conductivity and chargeability model
blk_inds_c = utils.model_builder.getIndicesSphere(np.r_[60.0, -25.0], 12.5,
mesh.gridCC)
blk_inds_r = utils.model_builder.getIndicesSphere(np.r_[140.0, -25.0],
12.5, mesh.gridCC)
blk_inds_charg = utils.model_builder.getIndicesSphere(
np.r_[100.0, -25], 12.5, mesh.gridCC)
sigma = np.ones(mesh.nC) * 1.0 / 100.0
sigma[blk_inds_c] = 1.0 / 10.0
sigma[blk_inds_r] = 1.0 / 1000.0
sigma[~actind] = 1.0 / 1e8
rho = 1.0 / sigma
charg = np.zeros(mesh.nC)
charg[blk_inds_charg] = 0.1
# Show the true conductivity model
if plotIt:
fig, axs = plt.subplots(2, 1, figsize=(12, 6))
temp_rho = rho.copy()
temp_rho[~actind] = np.nan
temp_charg = charg.copy()
temp_charg[~actind] = np.nan
out1 = mesh.plotImage(
temp_rho,
grid=True,
ax=axs[0],
gridOpts={"alpha": 0.2},
clim=(10, 1000),
pcolorOpts={
"cmap": "viridis",
"norm": colors.LogNorm()
},
)
out2 = mesh.plotImage(
temp_charg,
grid=True,
ax=axs[1],
gridOpts={"alpha": 0.2},
clim=(0, 0.1),
pcolorOpts={"cmap": "magma"},
)
for i in range(2):
axs[i].plot(
survey_dc.electrode_locations[:, 0],
survey_dc.electrode_locations[:, 1],
"kv",
)
axs[i].set_xlim(IO.grids[:, 0].min(), IO.grids[:, 0].max())
axs[i].set_ylim(-IO.grids[:, 1].max(), IO.grids[:, 1].min())
axs[i].set_aspect("equal")
cb = plt.colorbar(out1[0], ax=axs[0])
cb.set_label("Resistivity (ohm-m)")
cb = plt.colorbar(out2[0], ax=axs[1])
cb.set_label("Chargeability")
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_dc for resistivity
mtrue_dc = np.log(rho[actind])
# Generate 2.5D DC problem
# "N" means potential is defined at nodes
prb = DC.Simulation2DNodal(mesh,
survey=survey_dc,
rhoMap=mapping,
storeJ=True,
solver=Solver)
# Make synthetic DC data with 5% Gaussian noise
data_dc = prb.make_synthetic_data(mtrue_dc,
relative_error=0.05,
add_noise=True)
IO.data_dc = data_dc.dobs
# Generate mtrue_ip for chargability
mtrue_ip = charg[actind]
# Generate 2.5D DC problem
# "N" means potential is defined at nodes
survey_ip = IP.from_dc_to_ip_survey(survey_dc, dim="2.5D")
prb_ip = IP.Simulation2DNodal(mesh,
survey=survey_ip,
etaMap=actmap,
storeJ=True,
rho=rho,
solver=Solver)
data_ip = prb_ip.make_synthetic_data(mtrue_ip,
relative_error=0.05,
add_noise=True)
IO.data_ip = data_ip.dobs
# Show apparent resisitivty pseudo-section
if plotIt:
IO.plotPseudoSection(data_type="apparent_resistivity",
scale="log",
cmap="viridis")
plt.show()
# Show apparent chargeability pseudo-section
if plotIt:
IO.plotPseudoSection(data_type="apparent_chargeability",
scale="linear",
cmap="magma")
plt.show()
# Show apparent resisitivty histogram
if plotIt:
fig = plt.figure(figsize=(10, 4))
ax1 = plt.subplot(121)
out = hist(np.log10(abs(IO.voltages)), bins=20)
ax1.set_xlabel("log10 DC voltage (V)")
ax2 = plt.subplot(122)
out = hist(IO.apparent_resistivity, bins=20)
ax2.set_xlabel("Apparent Resistivity ($\Omega$m)")
plt.tight_layout()
plt.show()
# Set initial model based upon histogram
m0_dc = np.ones(actmap.nP) * np.log(100.0)
# Set standard deviation
# floor
data_dc.noise_floor = 10**(-3.2)
# percentage
data_dc.relative_error = 0.05
mopt_dc, pred_dc = DC.run_inversion(m0_dc,
prb,
data_dc,
actind,
mesh,
beta0_ratio=1e0,
use_sensitivity_weight=True)
# Convert obtained inversion model to resistivity
# rho = M(m), where M(.) is a mapping
rho_est = mapping * mopt_dc
rho_est[~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(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_dc.electrode_locations[:, 0],
survey_dc.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()
# Show apparent resisitivty histogram
if plotIt:
fig = plt.figure(figsize=(10, 4))
ax1 = plt.subplot(121)
out = hist(np.log10(abs(IO.voltages_ip)), bins=20)
ax1.set_xlabel("log10 IP voltage (V)")
ax2 = plt.subplot(122)
out = hist(IO.apparent_chargeability, bins=20)
ax2.set_xlabel("Apparent Chargeability (V/V)")
plt.tight_layout()
plt.show()
# Set initial model based upon histogram
m0_ip = np.ones(actmap.nP) * 1e-10
# Set standard deviation
# floor
data_ip.noise_floor = 10**(-4)
# percentage
data_ip.relative_error = 0.05
# Clean sensitivity function formed with true resistivity
prb_ip._Jmatrix = None
# Input obtained resistivity to form sensitivity
prb_ip.rho = mapping * mopt_dc
mopt_ip, _ = IP.run_inversion(
m0_ip,
prb_ip,
data_ip,
actind,
mesh,
upper=np.Inf,
lower=0.0,
beta0_ratio=1e0,
use_sensitivity_weight=True,
)
# Convert obtained inversion model to chargeability
# charg = M(m), where M(.) is a mapping for cells below topography
charg_est = actmap * mopt_ip
charg_est[~actind] = np.nan
charg_true = charg.copy()
charg_true[~actind] = np.nan
# show recovered chargeability
if plotIt:
fig, ax = plt.subplots(2, 1, figsize=(20, 6))
out1 = mesh.plotImage(charg_true,
clim=(0, 0.1),
pcolorOpts={"cmap": "magma"},
ax=ax[0])
out2 = mesh.plotImage(charg_est,
clim=(0, 0.1),
pcolorOpts={"cmap": "magma"},
ax=ax[1])
out = [out1, out2]
for i in range(2):
ax[i].plot(
survey_dc.electrode_locations[:, 0],
survey_dc.electrode_locations[:, 1],
"rv",
)
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,
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 = 0.0, 200.0
ymin, ymax = 0.0, 0.0
zmin, zmax = 0, 0
endl = np.array([[xmin, ymin, zmin], [xmax, ymax, zmax]])
# Generate DC survey object
survey = DCutils.gen_DCIPsurvey(endl,
survey_type=survey_type,
dim=2,
a=10,
b=10,
n=10)
survey = IO.from_ambn_locations_to_survey(
survey.locations_a,
survey.locations_b,
survey.locations_m,
survey.locations_n,
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 * 0.0])
survey.drape_electrodes_on_topography(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.Simulation2DNodal(mesh,
survey=survey,
rhoMap=mapping,
storeJ=True,
solver=Solver)
# Make synthetic DC data with 5% Gaussian noise
data = prb.make_synthetic_data(mtrue, relative_error=0.05, add_noise=True)
# Show apparent resisitivty pseudo-section
IO.plotPseudoSection(data=data.dobs / IO.G,
data_type="apparent_resistivity")
# Show apparent resisitivty histogram
fig = plt.figure()
out = hist(data.dobs / IO.G, bins=20)
plt.show()
# Set standard_deviation
# floor
eps = 10**(-3.2)
# percentage
relative = 0.05
dmisfit = data_misfit.L2DataMisfit(simulation=prb, data=data)
uncert = abs(data.dobs) * relative + eps
dmisfit.standard_deviation = uncert
# Map for a regularization
mesh_1d = discretize.TensorMesh([parametric_block.nP])
# Related to inversion
reg = regularization.Simple(mesh_1d, alpha_x=0.0)
opt = optimization.InexactGaussNewton(maxIter=10)
invProb = inverse_problem.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 = 0.0
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(plotIt=True, survey_type="dipole-dipole", p=0.0, qx=2.0, qz=2.0):
np.random.seed(1)
# Initiate I/O class for DC
IO = DC.IO()
# Obtain ABMN locations
xmin, xmax = 0.0, 200.0
ymin, ymax = 0.0, 0.0
zmin, zmax = 0, 0
endl = np.array([[xmin, ymin, zmin], [xmax, ymax, zmax]])
# Generate DC survey object
survey = gen_DCIPsurvey(endl,
survey_type=survey_type,
dim=2,
a=10,
b=10,
n=10)
survey = IO.from_abmn_locations_to_survey(
survey.locations_a,
survey.locations_b,
survey.locations_m,
survey.locations_n,
survey_type,
data_dc_type="volt",
)
# Obtain 2D TensorMesh
mesh, actind = IO.set_mesh()
topo, mesh1D = genTopography(mesh, -10, 0, its=100)
actind = utils.surface2ind_topo(mesh, np.c_[mesh1D.vectorCCx, topo])
survey.drape_electrodes_on_topography(mesh, actind, option="top")
# Build a conductivity model
blk_inds_c = utils.model_builder.getIndicesSphere(np.r_[60.0, -25.0], 12.5,
mesh.gridCC)
blk_inds_r = utils.model_builder.getIndicesSphere(np.r_[140.0, -25.0],
12.5, mesh.gridCC)
layer_inds = mesh.gridCC[:, 1] > -5.0
sigma = np.ones(mesh.nC) * 1.0 / 100.0
sigma[blk_inds_c] = 1.0 / 10.0
sigma[blk_inds_r] = 1.0 / 1000.0
sigma[~actind] = 1.0 / 1e8
rho = 1.0 / 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.Simulation2DNodal(mesh,
survey=survey,
rhoMap=mapping,
storeJ=True,
Solver=Solver,
verbose=True)
# Make synthetic DC data with 5% Gaussian noise
data = prb.make_synthetic_data(mtrue, relative_error=0.05, add_noise=True)
IO.data_dc = data.dobs
# Show apparent resisitivty pseudo-section
if plotIt:
IO.plotPseudoSection(data=data.dobs / IO.G,
data_type="apparent_resistivity")
# Show apparent resisitivty histogram
if plotIt:
fig = plt.figure()
out = hist(data.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(100.0)
# Set standard_deviation
# floor
eps = 10**(-3.2)
# percentage
relative = 0.05
dmisfit = data_misfit.L2DataMisfit(simulation=prb, data=data)
uncert = abs(data.dobs) * relative + eps
dmisfit.standard_deviation = 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, 0.0]
IRLS = directives.Update_IRLS(max_irls_iterations=20,
minGNiter=1,
beta_search=False,
fix_Jmatrix=True)
opt = optimization.InexactGaussNewton(maxIter=40)
invProb = inverse_problem.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()
bottomHalf = bottomHalf[0:-1, :]
cylinderPoints = np.vstack([topHalf, bottomHalf])
cylinderPoints = np.vstack([cylinderPoints, topHalf[0, :]])
return cylinderPoints
# Setup a synthetic Dipole-Dipole Survey
# Line 1
xmin, xmax = -15.0, 15.0
ymin, ymax = 0.0, 0.0
zmin, zmax = 0, 0
endl = np.array([[xmin, ymin, zmin], [xmax, ymax, zmax]])
survey1 = DCutils.gen_DCIPsurvey(endl,
"dipole-dipole",
dim=mesh.dim,
a=3,
b=3,
n=8)
# Line 2
xmin, xmax = -15.0, 15.0
ymin, ymax = 5.0, 5.0
zmin, zmax = 0, 0
endl = np.array([[xmin, ymin, zmin], [xmax, ymax, zmax]])
survey2 = DCutils.gen_DCIPsurvey(endl,
"dipole-dipole",
dim=mesh.dim,
a=3,
b=3,
n=8)