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 setUp(self):
cs = 25.
hx = [(cs, 0, -1.3), (cs, 21), (cs, 0, 1.3)]
hz = [(cs, 0, -1.3), (cs, 20)]
mesh = Mesh.TensorMesh([hx, hz], x0="CN")
blkind0 = Utils.ModelBuilder.getIndicesSphere(np.r_[-100., -200.], 75.,
mesh.gridCC)
blkind1 = Utils.ModelBuilder.getIndicesSphere(np.r_[100., -200.], 75.,
mesh.gridCC)
sigma = np.ones(mesh.nC) * 1e-2
eta = np.zeros(mesh.nC)
tau = np.ones_like(sigma) * 1.
eta[blkind0] = 0.1
eta[blkind1] = 0.1
tau[blkind0] = 0.1
tau[blkind1] = 0.1
x = mesh.vectorCCx[(mesh.vectorCCx > -155.) & (mesh.vectorCCx < 155.)]
Aloc = np.r_[-200., 0.]
Bloc = np.r_[200., 0.]
M = Utils.ndgrid(x - 25., np.r_[0.])
N = Utils.ndgrid(x + 25., np.r_[0.])
times = np.arange(10) * 1e-3 + 1e-3
rx = SIP.Rx.Dipole(M, N, times)
src = SIP.Src.Dipole([rx], Aloc, Bloc)
survey = SIP.Survey([src])
wires = Maps.Wires(('eta', mesh.nC), ('taui', mesh.nC))
problem = SIP.Problem2D_CC(mesh,
rho=1. / sigma,
etaMap=wires.eta,
tauiMap=wires.taui,
verbose=False)
problem.Solver = Solver
problem.pair(survey)
mSynth = np.r_[eta, 1. / tau]
problem.model = mSynth
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
dmis = DataMisfit.l2_DataMisfit(survey)
reg = Regularization.Tikhonov(mesh)
opt = Optimization.InexactGaussNewton(maxIterLS=20,
maxIter=10,
tolF=1e-6,
tolX=1e-6,
tolG=1e-6,
maxIterCG=6)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=1e4)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth
self.survey = survey
self.dmis = dmis
def setUp(self):
cs = 25.
hx = [(cs, 0, -1.3), (cs, 21), (cs, 0, 1.3)]
hy = [(cs, 0, -1.3), (cs, 21), (cs, 0, 1.3)]
hz = [(cs, 0, -1.3), (cs, 20)]
mesh = Mesh.TensorMesh([hx, hy, hz], x0="CCN")
blkind0 = Utils.ModelBuilder.getIndicesSphere(
np.r_[-100., -100., -200.], 75., mesh.gridCC
)
blkind1 = Utils.ModelBuilder.getIndicesSphere(
np.r_[100., 100., -200.], 75., mesh.gridCC
)
sigma = np.ones(mesh.nC)*1e-2
eta = np.zeros(mesh.nC)
tau = np.ones_like(sigma)*1.
eta[blkind0] = 0.1
eta[blkind1] = 0.1
tau[blkind0] = 0.1
tau[blkind1] = 0.01
x = mesh.vectorCCx[(mesh.vectorCCx > -155.) & (mesh.vectorCCx < 155.)]
y = mesh.vectorCCx[(mesh.vectorCCy > -155.) & (mesh.vectorCCy < 155.)]
Aloc = np.r_[-200., 0., 0.]
Bloc = np.r_[200., 0., 0.]
M = Utils.ndgrid(x-25., y, np.r_[0.])
N = Utils.ndgrid(x+25., y, np.r_[0.])
times = np.arange(10)*1e-3 + 1e-3
rx = SIP.Rx.Dipole(M, N, times)
src = SIP.Src.Dipole([rx], Aloc, Bloc)
survey = SIP.Survey([src])
wires = Maps.Wires(('eta', mesh.nC), ('taui', mesh.nC))
problem = SIP.Problem3D_N(
mesh,
sigma=sigma,
etaMap=wires.eta,
tauiMap=wires.taui
)
problem.Solver = Solver
problem.pair(survey)
mSynth = np.r_[eta, 1./tau]
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
dmis = DataMisfit.l2_DataMisfit(survey)
reg = Regularization.Tikhonov(mesh)
opt = Optimization.InexactGaussNewton(
maxIterLS=20, maxIter=10, tolF=1e-6,
tolX=1e-6, tolG=1e-6, maxIterCG=6
)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=1e4)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth
self.survey = survey
self.dmis = dmis
def setUp(self):
mesh = Mesh.TensorMesh([30, 30], x0=[-0.5, -1.])
sigma = np.ones(mesh.nC)
model = np.log(sigma)
prob = DC.Problem3D_CC(mesh, rhoMap=Maps.ExpMap(mesh))
rx = DC.Rx.Pole(
Utils.ndgrid([mesh.vectorCCx, np.r_[mesh.vectorCCy.max()]])
)
src = DC.Src.Dipole(
[rx], np.r_[-0.25, mesh.vectorCCy.max()],
np.r_[0.25, mesh.vectorCCy.max()]
)
survey = DC.Survey([src])
prob.pair(survey)
self.std = 0.01
survey.std = self.std
dobs = survey.makeSyntheticData(model)
self.eps = 1e-8 * np.min(np.abs(dobs))
survey.eps = self.eps
dmis = DataMisfit.l2_DataMisfit(survey)
self.model = model
self.mesh = mesh
self.survey = survey
self.prob = prob
self.dobs = dobs
self.dmis = dmis
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(delt=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=times, fieldType='dbdt', fieldComp='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)
Survey.t_active = np.zeros(Survey.nD, dtype=bool)
Survey.set_active_interval(-1e6, 1e6)
Problem = VRM.Problem_Linear(meshObj, ref_factor=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 setUp(self):
mesh = Mesh.TensorMesh([30, 30], x0=[-0.5, -1.])
sigma = np.ones(mesh.nC)
model = np.log(sigma)
prob = DC.Problem3D_CC(mesh, rhoMap=Maps.ExpMap(mesh))
rx = DC.Rx.Pole(
Utils.ndgrid([mesh.vectorCCx, np.r_[mesh.vectorCCy.max()]])
)
src = DC.Src.Dipole(
[rx], np.r_[-0.25, mesh.vectorCCy.max()],
np.r_[0.25, mesh.vectorCCy.max()]
)
survey = DC.Survey([src])
prob.pair(survey)
dobs = survey.makeSyntheticData(model)
dmis = DataMisfit.l2_DataMisfit(survey)
self.model = model
self.mesh = mesh
self.survey = survey
self.prob = prob
self.dobs = dobs
self.dmis = dmis
def setUp(self, parallel=False):
frequency = np.array([900, 7200, 56000], dtype=float)
hz = np.r_[1.]
n_sounding = 10
dx = 20.
hx = np.ones(n_sounding) * dx
e = np.ones(n_sounding)
mSynth = np.r_[e * np.log(1. / 100.), e * 20]
x = np.arange(n_sounding)
y = np.zeros_like(x)
z = np.ones_like(x) * 30.
rx_locations = np.c_[x, y, z]
src_locations = np.c_[x, y, z]
topo = np.c_[x, y, z - 30.].astype(float)
wires = Maps.Wires(('sigma', n_sounding), ('h', n_sounding))
expmap = Maps.ExpMap(nP=n_sounding)
sigmaMap = expmap * wires.sigma
survey = GlobalEM1DSurveyFD(rx_locations=rx_locations,
src_locations=src_locations,
frequency=frequency,
offset=np.ones_like(frequency) * 8.,
src_type="VMD",
rx_type="ppm",
field_type='secondary',
topo=topo,
half_switch=True)
problem = GlobalEM1DProblemFD([],
sigmaMap=sigmaMap,
hMap=wires.h,
hz=hz,
parallel=parallel,
n_cpu=2)
problem.pair(survey)
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
mesh = Mesh.TensorMesh([int(n_sounding * 2)])
dmis = DataMisfit.l2_DataMisfit(survey)
reg = Regularization.Tikhonov(mesh)
opt = Optimization.InexactGaussNewton(maxIterLS=20,
maxIter=10,
tolF=1e-6,
tolX=1e-6,
tolG=1e-6,
maxIterCG=6)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=0.)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth * 1.2
self.survey = survey
self.dmis = dmis
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 setUp(self, parallel=True):
frequency = np.array([900, 7200, 56000], dtype=float)
hz = get_vertical_discretization_frequency(
frequency, sigma_background=1./10.
)
n_sounding = 10
dx = 20.
hx = np.ones(n_sounding) * dx
mesh = Mesh.TensorMesh([hx, hz], x0='00')
inds = mesh.gridCC[:, 1] < 25
inds_1 = mesh.gridCC[:, 1] < 50
sigma = np.ones(mesh.nC) * 1./100.
sigma[inds_1] = 1./10.
sigma[inds] = 1./50.
sigma_em1d = sigma.reshape(mesh.vnC, order='F').flatten()
mSynth = np.log(sigma_em1d)
x = mesh.vectorCCx
y = np.zeros_like(x)
z = np.ones_like(x) * 30.
rx_locations = np.c_[x, y, z]
src_locations = np.c_[x, y, z]
topo = np.c_[x, y, z-30.].astype(float)
mapping = Maps.ExpMap(mesh)
survey = GlobalEM1DSurveyFD(
rx_locations=rx_locations,
src_locations=src_locations,
frequency=frequency,
offset=np.ones_like(frequency) * 8.,
src_type="VMD",
rx_type="Hz",
field_type='secondary',
topo=topo
)
problem = GlobalEM1DProblemFD(
[], sigmaMap=mapping, hz=hz,
parallel=parallel, n_cpu=5
)
problem.pair(survey)
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
dmis = DataMisfit.l2_DataMisfit(survey)
reg = Regularization.Tikhonov(mesh)
opt = Optimization.InexactGaussNewton(
maxIterLS=20, maxIter=10, tolF=1e-6,
tolX=1e-6, tolG=1e-6, maxIterCG=6
)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=0.)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth
self.survey = survey
self.dmis = dmis
def setUp(self, parallel=True):
frequency = np.array([900, 7200, 56000], dtype=float)
hz = get_vertical_discretization_frequency(
frequency, sigma_background=1./10.
)
n_sounding = 10
dx = 20.
hx = np.ones(n_sounding) * dx
mesh = Mesh.TensorMesh([hx, hz], x0='00')
inds = mesh.gridCC[:, 1] < 25
inds_1 = mesh.gridCC[:, 1] < 50
sigma = np.ones(mesh.nC) * 1./100.
sigma[inds_1] = 1./10.
sigma[inds] = 1./50.
sigma_em1d = sigma.reshape(mesh.vnC, order='F').flatten()
mSynth = np.log(sigma_em1d)
x = mesh.vectorCCx
y = np.zeros_like(x)
z = np.ones_like(x) * 30.
rx_locations = np.c_[x, y, z]
src_locations = np.c_[x, y, z]
topo = np.c_[x, y, z-30.].astype(float)
mapping = Maps.ExpMap(mesh)
survey = GlobalEM1DSurveyFD(
rx_locations=rx_locations,
src_locations=src_locations,
frequency=frequency,
offset=np.ones_like(frequency) * 8.,
src_type="VMD",
rx_type="Hz",
field_type='secondary',
topo=topo
)
problem = GlobalEM1DProblemFD(
[], sigmaMap=mapping, hz=hz,
parallel=parallel, n_cpu=2
)
problem.pair(survey)
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
dmis = DataMisfit.l2_DataMisfit(survey)
reg = Regularization.Tikhonov(mesh)
opt = Optimization.InexactGaussNewton(
maxIterLS=20, maxIter=10, tolF=1e-6,
tolX=1e-6, tolG=1e-6, maxIterCG=6
)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=0.)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth
self.survey = survey
self.dmis = dmis
def setUp(self, parallel=True):
frequency = np.array([900, 7200, 56000], dtype=float)
hz = np.r_[1.]
n_sounding = 10
dx = 20.
hx = np.ones(n_sounding) * dx
e = np.ones(n_sounding)
mSynth = np.r_[e*np.log(1./100.), e*20]
x = np.arange(n_sounding)
y = np.zeros_like(x)
z = np.ones_like(x) * 30.
rx_locations = np.c_[x, y, z]
src_locations = np.c_[x, y, z]
topo = np.c_[x, y, z-30.].astype(float)
wires = Maps.Wires(('sigma', n_sounding),('h', n_sounding))
expmap = Maps.ExpMap(nP=n_sounding)
sigmaMap = expmap * wires.sigma
survey = GlobalEM1DSurveyFD(
rx_locations=rx_locations,
src_locations=src_locations,
frequency=frequency,
offset=np.ones_like(frequency) * 8.,
src_type="VMD",
rx_type="ppm",
field_type='secondary',
topo=topo,
half_switch=True
)
problem = GlobalEM1DProblemFD(
[], sigmaMap=sigmaMap, hMap=wires.h, hz=hz,
parallel=parallel, n_cpu=2
)
problem.pair(survey)
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
mesh = Mesh.TensorMesh([int(n_sounding * 2)])
dmis = DataMisfit.l2_DataMisfit(survey)
reg = Regularization.Tikhonov(mesh)
opt = Optimization.InexactGaussNewton(
maxIterLS=20, maxIter=10, tolF=1e-6,
tolX=1e-6, tolG=1e-6, maxIterCG=6
)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=0.)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth * 1.2
self.survey = survey
self.dmis = dmis
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 setUp(self):
mesh = Mesh.TensorMesh([30, 30], x0=[-0.5, -1.])
sigma = np.random.rand(mesh.nC)
model = np.log(sigma)
prob = DC.Problem3D_CC(mesh, rhoMap=Maps.ExpMap(mesh))
prob1 = DC.Problem3D_CC(mesh, rhoMap=Maps.ExpMap(mesh))
rx = DC.Rx.Pole(
Utils.ndgrid([mesh.vectorCCx, np.r_[mesh.vectorCCy.max()]])
)
rx1 = DC.Rx.Pole(
Utils.ndgrid([mesh.vectorCCx, np.r_[mesh.vectorCCy.min()]])
)
src = DC.Src.Dipole(
[rx], np.r_[-0.25, mesh.vectorCCy.max()],
np.r_[0.25, mesh.vectorCCy.max()]
)
src1 = DC.Src.Dipole(
[rx1], np.r_[-0.25, mesh.vectorCCy.max()],
np.r_[0.25, mesh.vectorCCy.max()]
)
survey = DC.Survey([src])
prob.pair(survey)
survey1 = DC.Survey([src1])
prob1.pair(survey1)
dobs0 = survey.makeSyntheticData(model)
dobs1 = survey1.makeSyntheticData(model)
self.mesh = mesh
self.model = model
self.survey0 = survey
self.prob0 = prob
self.survey1 = survey1
self.prob1 = prob1
self.dmis0 = DataMisfit.l2_DataMisfit(self.survey0)
self.dmis1 = DataMisfit.l2_DataMisfit(self.survey1)
self.dmiscobmo = self.dmis0 + self.dmis1
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 makeSubProblem(args):
globalMesh, globalActive, globalSurvey, globalTree, ind, h, padDist = args
rxLoc = globalSurvey.srcField.rxList[0].locs
loc = np.c_[rxLoc[ind, :]].T
rx = PF.BaseMag.RxObs(loc)
srcField = PF.BaseMag.SrcField([rx], param=globalSurvey.srcField.param)
survey_t = PF.BaseMag.LinearSurvey(srcField)
survey_t.dobs = np.c_[globalSurvey.dobs[ind]]
survey_t.std = np.c_[globalSurvey.std[ind]]
survey_t.index = ind
# Create a mesh
# Keep same fine cells as global
h = [globalMesh.hx.min(), globalMesh.hy.min(), globalMesh.hz.min()]
mesh_t = Utils.modelutils.meshBuilder(rxLoc,
h,
padDist,
meshType='TREE',
meshGlobal=globalMesh,
verticalAlignment='center')
# Refine the mesh around loc
mesh_t = Utils.modelutils.refineTree(mesh_t,
loc,
dtype='point',
nCpad=[3, 3, 3],
finalize=True)
actv_t = np.ones(mesh_t.nC, dtype='bool')
# Create reduced identity map
tileMap = Maps.Tile((globalMesh, globalActive), (mesh_t, actv_t))
tileMap._tree = globalTree
# Create the forward model operator
prob_t = PF.Magnetics.MagneticIntegral(mesh_t,
chiMap=tileMap,
actInd=actv_t,
verbose=False)
survey_t.pair(prob_t)
# Pre-calc sensitivities and projections
prob_t.G
tileMap.P
# Data misfit function
dmis = DataMisfit.l2_DataMisfit(survey_t, eps=survey_t.std)
dmis.W = 1. / survey_t.std
return dmis
def setUp(self):
cs = 25.
hx = [(cs,0, -1.3),(cs,21),(cs,0, 1.3)]
hy = [(cs,0, -1.3),(cs,21),(cs,0, 1.3)]
hz = [(cs,0, -1.3),(cs,20),(cs,0, 1.3)]
mesh = Mesh.TensorMesh([hx, hy, hz],x0="CCC")
blkind0 = Utils.ModelBuilder.getIndicesSphere(np.r_[-100., -100., -200.], 75., mesh.gridCC)
blkind1 = Utils.ModelBuilder.getIndicesSphere(np.r_[100., 100., -200.], 75., mesh.gridCC)
sigma = np.ones(mesh.nC)*1e-2
airind = mesh.gridCC[:,2]>0.
sigma[airind] = 1e-8
eta = np.zeros(mesh.nC)
tau = np.ones_like(sigma)*1.
eta[blkind0] = 0.1
eta[blkind1] = 0.1
tau[blkind0] = 0.1
tau[blkind1] = 0.01
actmapeta = Maps.InjectActiveCells(mesh, ~airind, 0.)
actmaptau = Maps.InjectActiveCells(mesh, ~airind, 1.)
x = mesh.vectorCCx[(mesh.vectorCCx>-155.)&(mesh.vectorCCx<155.)]
y = mesh.vectorCCx[(mesh.vectorCCy>-155.)&(mesh.vectorCCy<155.)]
Aloc = np.r_[-200., 0., 0.]
Bloc = np.r_[200., 0., 0.]
M = Utils.ndgrid(x-25.,y, np.r_[0.])
N = Utils.ndgrid(x+25.,y, np.r_[0.])
times = np.arange(10)*1e-3 + 1e-3
rx = SIP.Rx.Dipole(M, N, times)
src = SIP.Src.Dipole([rx], Aloc, Bloc)
survey = SIP.Survey([src])
colemap = [("eta", Maps.IdentityMap(mesh)*actmapeta), ("taui", Maps.IdentityMap(mesh)*actmaptau)]
problem = SIP.Problem3D_N(mesh, sigma=sigma, mapping=colemap)
problem.Solver = Solver
problem.pair(survey)
mSynth = np.r_[eta[~airind], 1./tau[~airind]]
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
dmis = DataMisfit.l2_DataMisfit(survey)
regmap = Maps.IdentityMap(nP=int(mSynth[~airind].size*2))
reg = SIP.MultiRegularization(mesh, mapping=regmap, nModels=2, indActive=~airind)
opt = Optimization.InexactGaussNewton(maxIterLS=20, maxIter=10, tolF=1e-6, tolX=1e-6, tolG=1e-6, maxIterCG=6)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=1e4)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth
self.survey = survey
self.dmis = dmis
def setUp(self):
mesh = Mesh.TensorMesh([20, 20, 20], "CCN")
sigma = np.ones(mesh.nC) * 1. / 100.
actind = mesh.gridCC[:, 2] < -0.2
# actMap = Maps.InjectActiveCells(mesh, actind, 0.)
xyzM = Utils.ndgrid(
np.ones_like(mesh.vectorCCx[:-1]) * -0.4,
np.ones_like(mesh.vectorCCy) * -0.4, np.r_[-0.3])
xyzN = Utils.ndgrid(mesh.vectorCCx[1:], mesh.vectorCCy, np.r_[-0.3])
problem = SP.Problem_CC(mesh,
sigma=sigma,
qMap=Maps.IdentityMap(mesh),
Solver=PardisoSolver)
rx = SP.Rx.Dipole(xyzN, xyzM)
src = SP.Src.StreamingCurrents([rx],
L=np.ones(mesh.nC),
mesh=mesh,
modelType="CurrentSource")
survey = SP.Survey([src])
survey.pair(problem)
q = np.zeros(mesh.nC)
inda = Utils.closestPoints(mesh, np.r_[-0.5, 0., -0.8])
indb = Utils.closestPoints(mesh, np.r_[0.5, 0., -0.8])
q[inda] = 1.
q[indb] = -1.
mSynth = q.copy()
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
dmis = DataMisfit.l2_DataMisfit(survey)
reg = Regularization.Simple(mesh)
opt = Optimization.InexactGaussNewton(maxIterLS=20,
maxIter=10,
tolF=1e-6,
tolX=1e-6,
tolG=1e-6,
maxIterCG=6)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=1e-2)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth
self.survey = survey
self.dmis = dmis
def setUp(self):
mesh = Mesh.TensorMesh([30, 30], x0=[-0.5, -1.])
sigma = np.random.rand(mesh.nC)
model = np.log(sigma)
prob = DC.Problem3D_CC(mesh, rhoMap=Maps.ExpMap(mesh))
prob1 = DC.Problem3D_CC(mesh, rhoMap=Maps.ExpMap(mesh))
rx = DC.Rx.Pole(
Utils.ndgrid([mesh.vectorCCx, np.r_[mesh.vectorCCy.max()]]))
rx1 = DC.Rx.Pole(
Utils.ndgrid([mesh.vectorCCx, np.r_[mesh.vectorCCy.min()]]))
src = DC.Src.Dipole([rx], np.r_[-0.25, mesh.vectorCCy.max()],
np.r_[0.25, mesh.vectorCCy.max()])
src1 = DC.Src.Dipole([rx1], np.r_[-0.25, mesh.vectorCCy.max()],
np.r_[0.25, mesh.vectorCCy.max()])
survey = DC.Survey([src])
prob.pair(survey)
survey1 = DC.Survey([src1])
prob1.pair(survey1)
dobs0 = survey.makeSyntheticData(model)
dobs1 = survey1.makeSyntheticData(model)
self.mesh = mesh
self.model = model
self.survey0 = survey
self.prob0 = prob
self.survey1 = survey1
self.prob1 = prob1
self.dmis0 = DataMisfit.l2_DataMisfit(self.survey0)
self.dmis1 = DataMisfit.l2_DataMisfit(self.survey1)
self.dmiscobmo = self.dmis0 + self.dmis1
def setUp(self):
cs = 12.5
hx = [(cs, 7, -1.3), (cs, 61), (cs, 7, 1.3)]
hy = [(cs, 7, -1.3), (cs, 20)]
mesh = Mesh.TensorMesh([hx, hy], x0="CN")
# x = np.linspace(-200, 200., 20)
x = np.linspace(-200, 200., 2)
M = Utils.ndgrid(x - 12.5, np.r_[0.])
N = Utils.ndgrid(x + 12.5, np.r_[0.])
A0loc = np.r_[-150, 0.]
A1loc = np.r_[-130, 0.]
B0loc = np.r_[-130, 0.]
B1loc = np.r_[-110, 0.]
rx = DC.Rx.Dipole_ky(M, N)
src0 = DC.Src.Dipole([rx], A0loc, B0loc)
src1 = DC.Src.Dipole([rx], A1loc, B1loc)
survey = IP.Survey([src0, src1])
sigma = np.ones(mesh.nC) * 1.
problem = IP.Problem2D_CC(mesh,
sigma=sigma,
etaMap=Maps.IdentityMap(mesh),
verbose=False)
problem.pair(survey)
mSynth = np.ones(mesh.nC) * 0.1
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
dmis = DataMisfit.l2_DataMisfit(survey)
reg = Regularization.Tikhonov(mesh)
opt = Optimization.InexactGaussNewton(maxIterLS=20,
maxIter=10,
tolF=1e-6,
tolX=1e-6,
tolG=1e-6,
maxIterCG=6)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=1e4)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth
self.survey = survey
self.dmis = dmis
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 setUp(self):
cs = 12.5
hx = [(cs, 7, -1.3), (cs, 61), (cs, 7, 1.3)]
hy = [(cs, 7, -1.3), (cs, 20)]
mesh = Mesh.TensorMesh([hx, hy], x0="CN")
# x = np.linspace(-200, 200., 20)
x = np.linspace(-200, 200., 2)
M = Utils.ndgrid(x-12.5, np.r_[0.])
N = Utils.ndgrid(x+12.5, np.r_[0.])
A0loc = np.r_[-150, 0.]
A1loc = np.r_[-130, 0.]
B0loc = np.r_[-130, 0.]
B1loc = np.r_[-110, 0.]
rx = DC.Rx.Dipole_ky(M, N)
src0 = DC.Src.Dipole([rx], A0loc, B0loc)
src1 = DC.Src.Dipole([rx], A1loc, B1loc)
survey = IP.Survey([src0, src1])
sigma = np.ones(mesh.nC) * 1.
problem = IP.Problem2D_CC(
mesh, sigma=sigma, etaMap=Maps.IdentityMap(mesh),
verbose=False
)
problem.pair(survey)
mSynth = np.ones(mesh.nC)*0.1
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
dmis = DataMisfit.l2_DataMisfit(survey)
reg = Regularization.Tikhonov(mesh)
opt = Optimization.InexactGaussNewton(
maxIterLS=20, maxIter=10, tolF=1e-6,
tolX=1e-6, tolG=1e-6, maxIterCG=6
)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=1e4)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth
self.survey = survey
self.dmis = dmis
def run_inversion_direct(
self,
m0=0.0,
mref=0.0,
percentage=5,
floor=0.1,
chi_fact=1.0,
beta_min=1e-4,
beta_max=1e0,
n_beta=31,
alpha_s=1.0,
alpha_x=1.0,
):
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
betas = np.logspace(np.log10(beta_min), np.log10(beta_max),
n_beta)[::-1]
phi_d = np.zeros(n_beta, dtype=float)
phi_m = np.zeros(n_beta, dtype=float)
models = []
preds = []
G = dmis.W.dot(self.G)
for ii, beta in enumerate(betas):
A = G.T.dot(G) + beta * reg.deriv2(m0)
b = -(dmis.deriv(m0) + beta * reg.deriv(m0))
m = np.linalg.solve(A, b)
phi_d[ii] = dmis(m) * 2.0
phi_m[ii] = reg(m) * 2.0
models.append(m)
preds.append(survey.dpred(m))
return phi_d, phi_m, models, preds, betas
def setUp(self):
mesh = Mesh.TensorMesh([4, 4, 4])
# Magnetic inducing field parameter (A,I,D)
B = [50000, 90, 0]
# Create a MAGsurvey
rx = PF.BaseMag.RxObs(
np.vstack([[0.25, 0.25, 0.25], [-0.25, -0.25, 0.25]])
)
srcField = PF.BaseMag.SrcField([rx], param=(B[0], B[1], B[2]))
survey = PF.BaseMag.LinearSurvey(srcField)
# Create the forward model operator
prob = PF.Magnetics.MagneticIntegral(
mesh, chiMap=Maps.IdentityMap(mesh)
)
# Pair the survey and problem
survey.pair(prob)
# Compute forward model some data
m = np.random.rand(mesh.nC)
survey.makeSyntheticData(m)
reg = Regularization.Sparse(mesh)
reg.mref = np.zeros(mesh.nC)
wr = np.sum(prob.G**2., axis=0)**0.5
reg.cell_weights = wr
reg.norms = [0, 1, 1, 1]
reg.eps_p, reg.eps_q = 1e-3, 1e-3
# Data misfit function
dmis = DataMisfit.l2_DataMisfit(survey)
dmis.W = 1./survey.std
# Add directives to the inversion
opt = Optimization.ProjectedGNCG(
maxIter=2, lower=-10., upper=10.,
maxIterCG=2
)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
self.mesh = mesh
self.invProb = invProb
def setUp(self):
mesh = Mesh.TensorMesh([4, 4, 4])
# Magnetic inducing field parameter (A,I,D)
B = [50000, 90, 0]
# Create a MAGsurvey
rx = PF.BaseMag.RxObs(
np.vstack([[0.25, 0.25, 0.25], [-0.25, -0.25, 0.25]]))
srcField = PF.BaseMag.SrcField([rx], param=(B[0], B[1], B[2]))
survey = PF.BaseMag.LinearSurvey(srcField)
# Create the forward model operator
prob = PF.Magnetics.MagneticIntegral(mesh,
chiMap=Maps.IdentityMap(mesh))
# Pair the survey and problem
survey.pair(prob)
# Compute forward model some data
m = np.random.rand(mesh.nC)
survey.makeSyntheticData(m)
reg = Regularization.Sparse(mesh)
reg.mref = np.zeros(mesh.nC)
wr = np.sum(prob.G**2., axis=0)**0.5
reg.cell_weights = wr
reg.norms = [0, 1, 1, 1]
reg.eps_p, reg.eps_q = 1e-3, 1e-3
# Data misfit function
dmis = DataMisfit.l2_DataMisfit(survey)
dmis.W = 1. / survey.std
# Add directives to the inversion
opt = Optimization.ProjectedGNCG(maxIter=2,
lower=-10.,
upper=10.,
maxIterCG=2)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
self.mesh = mesh
self.invProb = invProb
def setUp(self):
aSpacing = 2.5
nElecs = 10
surveySize = nElecs * aSpacing - aSpacing
cs = surveySize / nElecs / 4
mesh = Mesh.TensorMesh(
[
[(cs, 10, -1.3), (cs, surveySize / cs), (cs, 10, 1.3)],
[(cs, 3, -1.3), (cs, 3, 1.3)],
# [(cs, 5, -1.3), (cs, 10)]
],
'CN')
srcList = DC.Utils.WennerSrcList(nElecs, aSpacing, in2D=True)
survey = DC.Survey(srcList)
problem = DC.Problem3D_N(mesh,
rhoMap=Maps.IdentityMap(mesh),
storeJ=True)
problem.pair(survey)
mSynth = np.ones(mesh.nC)
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
dmis = DataMisfit.l2_DataMisfit(survey)
reg = Regularization.Tikhonov(mesh)
opt = Optimization.InexactGaussNewton(maxIterLS=20,
maxIter=10,
tolF=1e-6,
tolX=1e-6,
tolG=1e-6,
maxIterCG=6)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=1e4)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth
self.survey = survey
self.dmis = dmis
def setUp(self):
mesh = Mesh.TensorMesh([20, 20, 20], "CCN")
sigma = np.ones(mesh.nC)*1./100.
actind = mesh.gridCC[:, 2] < -0.2
# actMap = Maps.InjectActiveCells(mesh, actind, 0.)
xyzM = Utils.ndgrid(np.ones_like(mesh.vectorCCx[:-1])*-0.4, np.ones_like(mesh.vectorCCy)*-0.4, np.r_[-0.3])
xyzN = Utils.ndgrid(mesh.vectorCCx[1:], mesh.vectorCCy, np.r_[-0.3])
problem = SP.Problem_CC(mesh, sigma=sigma, qMap=Maps.IdentityMap(mesh), Solver=PardisoSolver)
rx = SP.Rx.Dipole(xyzN, xyzM)
src = SP.Src.StreamingCurrents([rx], L=np.ones(mesh.nC), mesh=mesh,
modelType="CurrentSource")
survey = SP.Survey([src])
survey.pair(problem)
q = np.zeros(mesh.nC)
inda = Utils.closestPoints(mesh, np.r_[-0.5, 0., -0.8])
indb = Utils.closestPoints(mesh, np.r_[0.5, 0., -0.8])
q[inda] = 1.
q[indb] = -1.
mSynth = q.copy()
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
dmis = DataMisfit.l2_DataMisfit(survey)
reg = Regularization.Simple(mesh)
opt = Optimization.InexactGaussNewton(
maxIterLS=20, maxIter=10, tolF=1e-6,
tolX=1e-6, tolG=1e-6, maxIterCG=6
)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=1e-2)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth
self.survey = survey
self.dmis = dmis
def setUp(self):
cs = 12.5
hx = [(cs, 7, -1.3), (cs, 61), (cs, 7, 1.3)]
hy = [(cs, 7, -1.3), (cs, 20)]
mesh = Mesh.TensorMesh([hx, hy], x0="CN")
x = np.linspace(-135, 250., 20)
M = Utils.ndgrid(x - 12.5, np.r_[0.])
N = Utils.ndgrid(x + 12.5, np.r_[0.])
A0loc = np.r_[-150, 0.]
A1loc = np.r_[-130, 0.]
rxloc = [np.c_[M, np.zeros(20)], np.c_[N, np.zeros(20)]]
rx = DC.Rx.Dipole_ky(M, N)
src0 = DC.Src.Pole([rx], A0loc)
src1 = DC.Src.Pole([rx], A1loc)
survey = DC.Survey_ky([src0, src1])
problem = DC.Problem2D_N(mesh,
mapping=[('rho', Maps.IdentityMap(mesh))])
problem.pair(survey)
mSynth = np.ones(mesh.nC) * 1.
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
dmis = DataMisfit.l2_DataMisfit(survey)
reg = Regularization.Tikhonov(mesh)
opt = Optimization.InexactGaussNewton(maxIterLS=20,
maxIter=10,
tolF=1e-6,
tolX=1e-6,
tolG=1e-6,
maxIterCG=6)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=1e0)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth
self.survey = survey
self.dmis = dmis
def setUp(self):
cs = 12.5
hx = [(cs, 2, -1.3), (cs, 61), (cs, 2, 1.3)]
hy = [(cs, 2, -1.3), (cs, 20)]
mesh = Mesh.TensorMesh([hx, hy], x0="CN")
x = np.linspace(-135, 250., 20)
M = Utils.ndgrid(x-12.5, np.r_[0.])
N = Utils.ndgrid(x+12.5, np.r_[0.])
A0loc = np.r_[-150, 0.]
A1loc = np.r_[-130, 0.]
# rxloc = [np.c_[M, np.zeros(20)], np.c_[N, np.zeros(20)]]
rx = DC.Rx.Dipole_ky(M, N)
src0 = DC.Src.Pole([rx], A0loc)
src1 = DC.Src.Pole([rx], A1loc)
survey = DC.Survey_ky([src0, src1])
problem = DC.Problem2D_N(
mesh, rhoMap=Maps.IdentityMap(mesh),
Solver=Solver
)
problem.pair(survey)
mSynth = np.ones(mesh.nC)*1.
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
dmis = DataMisfit.l2_DataMisfit(survey)
reg = Regularization.Tikhonov(mesh)
opt = Optimization.InexactGaussNewton(
maxIterLS=20, maxIter=10, tolF=1e-6,
tolX=1e-6, tolG=1e-6, maxIterCG=6
)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=1e0)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth
self.survey = survey
self.dmis = dmis
def setUp(self):
aSpacing = 2.5
nElecs = 10
surveySize = nElecs*aSpacing - aSpacing
cs = surveySize / nElecs / 4
mesh = Mesh.TensorMesh([
[(cs, 10, -1.3), (cs, surveySize / cs), (cs, 10, 1.3)],
[(cs, 3, -1.3), (cs, 3, 1.3)],
# [(cs, 5, -1.3), (cs, 10)]
], 'CN')
srcList = DC.Utils.WennerSrcList(nElecs, aSpacing, in2D=True)
survey = DC.Survey(srcList)
problem = DC.Problem3D_N(
mesh, rhoMap=Maps.IdentityMap(mesh), storeJ=True
)
problem.pair(survey)
mSynth = np.ones(mesh.nC)
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
dmis = DataMisfit.l2_DataMisfit(survey)
reg = Regularization.Tikhonov(mesh)
opt = Optimization.InexactGaussNewton(
maxIterLS=20, maxIter=10, tolF=1e-6,
tolX=1e-6, tolG=1e-6, maxIterCG=6
)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=1e4)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth
self.survey = survey
self.dmis = dmis
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 setUp(self):
time = np.logspace(-3, 0, 21)
n_loc = 5
wires = Maps.Wires(('eta', n_loc), ('tau', n_loc), ('c', n_loc))
taumap = Maps.ExpMap(nP=n_loc) * wires.tau
etamap = Maps.ExpMap(nP=n_loc) * wires.eta
cmap = Maps.ExpMap(nP=n_loc) * wires.c
survey = SEMultiSurvey(time=time, locs=np.zeros((n_loc, 3)), n_pulse=0)
mesh = Mesh.TensorMesh([np.ones(int(n_loc * 3))])
prob = SEMultiInvProblem(mesh, etaMap=etamap, tauMap=taumap, cMap=cmap)
prob.pair(survey)
eta0, tau0, c0 = 0.1, 10., 0.5
m0 = np.log(np.r_[eta0 * np.ones(n_loc), tau0 * np.ones(n_loc),
c0 * np.ones(n_loc)])
survey.makeSyntheticData(m0)
# Now set up the problem to do some minimization
dmis = DataMisfit.l2_DataMisfit(survey)
reg = regularization.Tikhonov(mesh)
opt = Optimization.InexactGaussNewton(maxIterLS=20,
maxIter=10,
tolF=1e-6,
tolX=1e-6,
tolG=1e-6,
maxIterCG=6)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=0.)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = prob
self.survey = survey
self.m0 = m0
self.dmis = dmis
self.mesh = mesh
cb = plt.colorbar(dat[0], ax=ax[0])
ax[0].set_title("Vertical section")
cb.set_label("Conductivity (S/m)")
ax[0].set_xlabel('Easting (m)')
ax[0].set_ylabel('Depth (m)')
ax[0].set_xlim(-1000., 1000.)
ax[0].set_ylim(-500., 0.)
###############################################################################
# Step 6
# ------
#
# Run inversion
regmesh = Mesh.TensorMesh([31])
dmis = DataMisfit.l2_DataMisfit(survey)
reg = Regularization.Tikhonov(regmesh)
opt = Optimization.InexactGaussNewton(maxIter=7, tolX=1e-15)
opt.remember('xc')
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
beta = Directives.BetaEstimate_ByEig(beta0_ratio=1e1)
betaSched = Directives.BetaSchedule(coolingFactor=5, coolingRate=2)
inv = Inversion.BaseInversion(invProb, directiveList=[beta, betaSched])
# Choose an initial starting model of the background conductivity
m0 = np.log(np.ones(mapping.nP)*sighalf)
mopt = inv.run(m0)
###############################################################################
# Step 7
def createLocalProb(rxLoc, wrGlobal, lims):
# Grab the data for current tile
ind_t = np.all([
rxLoc[:, 0] >= lims[0], rxLoc[:, 0] <= lims[1],
rxLoc[:, 1] >= lims[2], rxLoc[:, 1] <= lims[3], surveyMask
],
axis=0)
# Remember selected data in case of tile overlap
surveyMask[ind_t] = False
# Create new survey
rxLoc_t = PF.BaseGrav.RxObs(rxLoc[ind_t, :])
srcField = PF.BaseGrav.SrcField([rxLoc_t])
survey_t = PF.BaseGrav.LinearSurvey(srcField)
survey_t.dobs = survey.dobs[ind_t]
survey_t.std = survey.std[ind_t]
survey_t.ind = ind_t
# mesh_t = meshTree.copy()
mesh_t = Utils.modelutils.meshBuilder(rxLoc[ind_t, :],
h,
padDist,
meshGlobal=meshInput,
meshType='TREE',
gridLoc='CC')
mesh_t = Utils.modelutils.refineTree(mesh_t,
topo,
dtype='surface',
nCpad=[0, 3, 2],
finalize=False)
mesh_t = Utils.modelutils.refineTree(mesh_t,
rxLoc[ind_t, :],
dtype='surface',
nCpad=[10, 5, 5],
finalize=False)
center = np.mean(rxLoc[ind_t, :], axis=0)
tileCenter = np.r_[np.mean(lims[0:2]), np.mean(lims[2:]), center[2]]
ind = closestPoints(mesh, tileCenter, gridLoc='CC')
shift = np.squeeze(mesh.gridCC[ind, :]) - center
mesh_t.x0 += shift
mesh_t.finalize()
print(mesh_t.nC)
actv_t = Utils.surface2ind_topo(mesh_t, topo)
# Create reduced identity map
tileMap = Maps.Tile((mesh, actv), (mesh_t, actv_t))
tileMap.nCell = 40
tileMap.nBlock = 1
# Create the forward model operator
prob = PF.Gravity.GravityIntegral(mesh_t,
rhoMap=tileMap,
actInd=actv_t,
memory_saving_mode=True,
parallelized=True)
survey_t.pair(prob)
# Data misfit function
dmis = DataMisfit.l2_DataMisfit(survey_t)
dmis.W = 1. / survey_t.std
wrGlobal += prob.getJtJdiag(np.ones(tileMap.P.shape[1]))
# Create combo misfit function
return dmis, wrGlobal
def createLocalProb(meshLocal, local_survey, global_weights, ind):
"""
CreateLocalProb(rxLoc, global_weights, lims, ind)
Generate a problem, calculate/store sensitivities for
given data points
"""
# Need to find a way to compute sensitivities only for intersecting cells
activeCells_t = np.ones(meshLocal.nC, dtype='bool')
# Create reduced identity map
if input_dict["inversion_type"] in ['mvi', 'mvis']:
nBlock = 3
else:
nBlock = 1
tile_map = Maps.Tile(
(mesh, activeCells),
(meshLocal, activeCells_t),
nBlock=nBlock
)
activeCells_t = tile_map.activeLocal
if "adjust_clearance" in list(input_dict.keys()):
print("Setting Z values of data to respect clearance height")
_, c_ind = tree.query(local_survey.rxLoc)
dz = input_dict["adjust_clearance"]
z = (
mesh.gridCC[activeCells, 2][c_ind] +
mesh.h_gridded[activeCells, 2][c_ind]/2 +
dz
)
local_survey.srcField.rxList[0].locs[:, 2] = z
if input_dict["inversion_type"] == 'grav':
prob = PF.Gravity.GravityIntegral(
meshLocal, rhoMap=tile_map*model_map, actInd=activeCells_t,
parallelized=parallelized,
Jpath=outDir + "Tile" + str(ind) + ".zarr",
maxRAM=max_ram,
n_cpu=n_cpu,
max_chunk_size=max_chunk_size, chunk_by_rows=chunk_by_rows
)
elif input_dict["inversion_type"] == 'mag':
prob = PF.Magnetics.MagneticIntegral(
meshLocal, chiMap=tile_map*model_map, actInd=activeCells_t,
parallelized=parallelized,
Jpath=outDir + "Tile" + str(ind) + ".zarr",
maxRAM=max_ram,
n_cpu=n_cpu,
max_chunk_size=max_chunk_size, chunk_by_rows=chunk_by_rows
)
elif input_dict["inversion_type"] in ['mvi', 'mvis']:
prob = PF.Magnetics.MagneticIntegral(
meshLocal, chiMap=tile_map*model_map, actInd=activeCells_t,
parallelized=parallelized,
Jpath=outDir + "Tile" + str(ind) + ".zarr",
maxRAM=max_ram,
modelType='vector',
n_cpu=n_cpu,
max_chunk_size=max_chunk_size, chunk_by_rows=chunk_by_rows
)
local_survey.pair(prob)
# Data misfit function
local_misfit = DataMisfit.l2_DataMisfit(local_survey)
local_misfit.W = 1./local_survey.std
wr = prob.getJtJdiag(np.ones_like(mstart), W=local_misfit.W)
activeCellsTemp = Maps.InjectActiveCells(mesh, activeCells, 1e-8)
global_weights += wr
del meshLocal
if output_tile_files:
if input_dict["inversion_type"] == 'grav':
Utils.io_utils.writeUBCgravityObservations(
outDir + 'Survey_Tile' + str(ind) + '.dat',
local_survey, local_survey.dobs
)
elif input_dict["inversion_type"] == 'mag':
Utils.io_utils.writeUBCmagneticsObservations(
outDir + 'Survey_Tile' + str(ind) + '.dat',
local_survey, local_survey.dobs
)
Mesh.TreeMesh.writeUBC(
mesh, outDir + 'Octree_Tile' + str(ind) + '.msh',
models={outDir + 'JtJ_Tile' + str(ind) + ' .act': activeCellsTemp*wr[:nC]}
)
return local_misfit, global_weights
srclist.append(src)
#print "line2",locA,locB,"\n",[M,N],"\n"
#rx = DC.Rx.Dipole(-M,-N)
#src= DC.Src.Dipole([rx],-locA,-locB)
#srclist.append(src)
mapping = Maps.ExpMap(mesh)
survey = DC.Survey(srclist)
problem = DC.Problem3D_CC(mesh, sigmaMap=mapping)
problem.pair(survey)
problem.Solver = PardisoSolver
survey.dobs = survey.dpred(mtrue)
survey.std = 0.05 * np.ones_like(survey.dobs)
survey.eps = 1e-5 * np.linalg.norm(survey.dobs)
dmisAll = DataMisfit.l2_DataMisfit(survey)
print '# of data: ', survey.dobs.shape
class SimultaneousSrc(DC.Src.BaseSrc):
"""
Dipole source
"""
QW = None
Q = None
W = None
def __init__(self, rxList, Q, W, **kwargs):
SimPEG.Survey.BaseSrc.__init__(self, rxList, **kwargs)
def setUp(self):
np.random.seed(0)
# Define the inducing field parameter
H0 = (50000, 90, 0)
# Create a mesh
dx = 5.0
hxind = [(dx, 5, -1.3), (dx, 5), (dx, 5, 1.3)]
hyind = [(dx, 5, -1.3), (dx, 5), (dx, 5, 1.3)]
hzind = [(dx, 5, -1.3), (dx, 6)]
mesh = Mesh.TensorMesh([hxind, hyind, hzind], "CCC")
# Get index of the center
midx = int(mesh.nCx / 2)
midy = int(mesh.nCy / 2)
# Lets create a simple Gaussian topo and set the active cells
[xx, yy] = np.meshgrid(mesh.vectorNx, mesh.vectorNy)
zz = -np.exp((xx ** 2 + yy ** 2) / 75 ** 2) + mesh.vectorNz[-1]
# Go from topo to actv cells
topo = np.c_[Utils.mkvc(xx), Utils.mkvc(yy), Utils.mkvc(zz)]
actv = Utils.surface2ind_topo(mesh, topo, "N")
actv = np.asarray([inds for inds, elem in enumerate(actv, 1) if elem], dtype=int) - 1
# Create active map to go from reduce space to full
actvMap = Maps.InjectActiveCells(mesh, actv, -100)
nC = len(actv)
# Create and array of observation points
xr = np.linspace(-20.0, 20.0, 20)
yr = np.linspace(-20.0, 20.0, 20)
X, Y = np.meshgrid(xr, yr)
# Move the observation points 5m above the topo
Z = -np.exp((X ** 2 + Y ** 2) / 75 ** 2) + mesh.vectorNz[-1] + 5.0
# Create a MAGsurvey
rxLoc = np.c_[Utils.mkvc(X.T), Utils.mkvc(Y.T), Utils.mkvc(Z.T)]
rxLoc = PF.BaseMag.RxObs(rxLoc)
srcField = PF.BaseMag.SrcField([rxLoc], param=H0)
survey = PF.BaseMag.LinearSurvey(srcField)
# We can now create a susceptibility model and generate data
# Here a simple block in half-space
model = np.zeros((mesh.nCx, mesh.nCy, mesh.nCz))
model[(midx - 2) : (midx + 2), (midy - 2) : (midy + 2), -6:-2] = 0.02
model = Utils.mkvc(model)
self.model = model[actv]
# Create active map to go from reduce set to full
actvMap = Maps.InjectActiveCells(mesh, actv, -100)
# Creat reduced identity map
idenMap = Maps.IdentityMap(nP=nC)
# Create the forward model operator
prob = PF.Magnetics.MagneticIntegral(mesh, mapping=idenMap, actInd=actv)
# Pair the survey and problem
survey.pair(prob)
# Compute linear forward operator and compute some data
d = prob.fields(self.model)
# Add noise and uncertainties (1nT)
data = d + np.random.randn(len(d))
wd = np.ones(len(data)) * 1.0
survey.dobs = data
survey.std = wd
# Create sensitivity weights from our linear forward operator
wr = np.sum(prob.G ** 2.0, axis=0) ** 0.5
wr = wr / np.max(wr)
# Create a regularization
reg = Regularization.Sparse(mesh, indActive=actv, mapping=idenMap)
reg.cell_weights = wr
# Data misfit function
dmis = DataMisfit.l2_DataMisfit(survey)
dmis.Wd = 1 / wd
# Add directives to the inversion
opt = Optimization.ProjectedGNCG(maxIter=100, lower=0.0, upper=1.0, maxIterLS=20, maxIterCG=10, tolCG=1e-3)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
betaest = Directives.BetaEstimate_ByEig()
# Here is where the norms are applied
IRLS = Directives.Update_IRLS(norms=([0, 1, 1, 1]), eps=(1e-3, 1e-3), f_min_change=1e-3, minGNiter=3)
update_Jacobi = Directives.Update_lin_PreCond()
self.inv = Inversion.BaseInversion(invProb, directiveList=[IRLS, betaest, update_Jacobi])
def run(plotIt=True, cleanAfterRun=True):
# Start by downloading files from the remote repository
# directory where the downloaded files are
url = "https://storage.googleapis.com/simpeg/Chile_GRAV_4_Miller/Chile_GRAV_4_Miller.tar.gz"
downloads = download(url, overwrite=True)
basePath = downloads.split(".")[0]
# unzip the tarfile
tar = tarfile.open(downloads, "r")
tar.extractall()
tar.close()
input_file = basePath + os.path.sep + 'LdM_input_file.inp'
# %% User input
# Plotting parameters, max and min densities in g/cc
vmin = -0.6
vmax = 0.6
# weight exponent for default weighting
wgtexp = 3.
# %%
# Read in the input file which included all parameters at once
# (mesh, topo, model, survey, inv param, etc.)
driver = PF.GravityDriver.GravityDriver_Inv(input_file)
# %%
# Now we need to create the survey and model information.
# Access the mesh and survey information
mesh = driver.mesh
survey = driver.survey
# define gravity survey locations
rxLoc = survey.srcField.rxList[0].locs
# define gravity data and errors
d = survey.dobs
wd = survey.std
# Get the active cells
active = driver.activeCells
nC = len(active) # Number of active cells
# Create active map to go from reduce set to full
activeMap = Maps.InjectActiveCells(mesh, active, -100)
# Create static map
static = driver.staticCells
dynamic = driver.dynamicCells
staticCells = Maps.InjectActiveCells(None,
dynamic,
driver.m0[static],
nC=nC)
mstart = driver.m0[dynamic]
# Get index of the center
midx = int(mesh.nCx / 2)
# %%
# Now that we have a model and a survey we can build the linear system ...
# Create the forward model operator
prob = PF.Gravity.GravityIntegral(mesh, rhoMap=staticCells, actInd=active)
prob.solverOpts['accuracyTol'] = 1e-4
# Pair the survey and problem
survey.pair(prob)
# Apply depth weighting
wr = PF.Magnetics.get_dist_wgt(mesh, rxLoc, active, wgtexp,
np.min(mesh.hx) / 4.)
wr = wr**2.
# %% Create inversion objects
reg = Regularization.Sparse(mesh,
indActive=active,
mapping=staticCells,
gradientType='total')
reg.mref = driver.mref[dynamic]
reg.cell_weights = wr * mesh.vol[active]
reg.norms = np.c_[0., 1., 1., 1.]
# reg.norms = driver.lpnorms
# Specify how the optimization will proceed
opt = Optimization.ProjectedGNCG(maxIter=20,
lower=driver.bounds[0],
upper=driver.bounds[1],
maxIterLS=10,
maxIterCG=20,
tolCG=1e-3)
# Define misfit function (obs-calc)
dmis = DataMisfit.l2_DataMisfit(survey)
dmis.W = 1. / wd
# 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(beta0_ratio=1e-2)
# IRLS sets up the Lp inversion problem
# Set the eps parameter parameter in Line 11 of the
# input file based on the distribution of model (DEFAULT = 95th %ile)
IRLS = Directives.Update_IRLS(f_min_change=1e-4,
maxIRLSiter=40,
beta_tol=5e-1)
# Preconditioning refreshing for each IRLS iteration
update_Jacobi = Directives.UpdatePreconditioner()
# Create combined the L2 and Lp problem
inv = Inversion.BaseInversion(invProb,
directiveList=[IRLS, update_Jacobi, betaest])
# %%
# Run L2 and Lp inversion
mrec = inv.run(mstart)
if cleanAfterRun:
os.remove(downloads)
shutil.rmtree(basePath)
# %%
if plotIt:
# Plot observed data
PF.Magnetics.plot_obs_2D(rxLoc, d, 'Observed Data')
# %%
# Write output model and data files and print misft stats.
# reconstructing l2 model mesh with air cells and active dynamic cells
L2out = activeMap * invProb.l2model
# reconstructing lp model mesh with air cells and active dynamic cells
Lpout = activeMap * mrec
# %%
# Plot out sections and histograms of the smooth l2 model.
# The ind= parameter is the slice of the model from top down.
yslice = midx + 1
L2out[L2out == -100] = np.nan # set "air" to nan
plt.figure(figsize=(10, 7))
plt.suptitle('Smooth Inversion: Depth weight = ' + str(wgtexp))
ax = plt.subplot(221)
dat1 = mesh.plotSlice(L2out,
ax=ax,
normal='Z',
ind=-16,
clim=(vmin, vmax),
pcolorOpts={'cmap': 'bwr'})
plt.plot(np.array([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
np.array([mesh.vectorCCy[yslice], mesh.vectorCCy[yslice]]),
c='gray',
linestyle='--')
plt.scatter(rxLoc[0:, 0], rxLoc[0:, 1], color='k', s=1)
plt.title('Z: ' + str(mesh.vectorCCz[-16]) + ' m')
plt.xlabel('Easting (m)')
plt.ylabel('Northing (m)')
plt.gca().set_aspect('equal', adjustable='box')
cb = plt.colorbar(dat1[0],
orientation="vertical",
ticks=np.linspace(vmin, vmax, 4))
cb.set_label('Density (g/cc$^3$)')
ax = plt.subplot(222)
dat = mesh.plotSlice(L2out,
ax=ax,
normal='Z',
ind=-27,
clim=(vmin, vmax),
pcolorOpts={'cmap': 'bwr'})
plt.plot(np.array([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
np.array([mesh.vectorCCy[yslice], mesh.vectorCCy[yslice]]),
c='gray',
linestyle='--')
plt.scatter(rxLoc[0:, 0], rxLoc[0:, 1], color='k', s=1)
plt.title('Z: ' + str(mesh.vectorCCz[-27]) + ' m')
plt.xlabel('Easting (m)')
plt.ylabel('Northing (m)')
plt.gca().set_aspect('equal', adjustable='box')
cb = plt.colorbar(dat1[0],
orientation="vertical",
ticks=np.linspace(vmin, vmax, 4))
cb.set_label('Density (g/cc$^3$)')
ax = plt.subplot(212)
mesh.plotSlice(L2out,
ax=ax,
normal='Y',
ind=yslice,
clim=(vmin, vmax),
pcolorOpts={'cmap': 'bwr'})
plt.title('Cross Section')
plt.xlabel('Easting(m)')
plt.ylabel('Elevation')
plt.gca().set_aspect('equal', adjustable='box')
cb = plt.colorbar(dat1[0],
orientation="vertical",
ticks=np.linspace(vmin, vmax, 4),
cmap='bwr')
cb.set_label('Density (g/cc$^3$)')
# %%
# Make plots of Lp model
yslice = midx + 1
Lpout[Lpout == -100] = np.nan # set "air" to nan
plt.figure(figsize=(10, 7))
plt.suptitle('Compact Inversion: Depth weight = ' + str(wgtexp) +
': $\epsilon_p$ = ' + str(round(reg.eps_p, 1)) +
': $\epsilon_q$ = ' + str(round(reg.eps_q, 2)))
ax = plt.subplot(221)
dat = mesh.plotSlice(Lpout,
ax=ax,
normal='Z',
ind=-16,
clim=(vmin, vmax),
pcolorOpts={'cmap': 'bwr'})
plt.plot(np.array([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
np.array([mesh.vectorCCy[yslice], mesh.vectorCCy[yslice]]),
c='gray',
linestyle='--')
plt.scatter(rxLoc[0:, 0], rxLoc[0:, 1], color='k', s=1)
plt.title('Z: ' + str(mesh.vectorCCz[-16]) + ' m')
plt.xlabel('Easting (m)')
plt.ylabel('Northing (m)')
plt.gca().set_aspect('equal', adjustable='box')
cb = plt.colorbar(dat[0],
orientation="vertical",
ticks=np.linspace(vmin, vmax, 4))
cb.set_label('Density (g/cc$^3$)')
ax = plt.subplot(222)
dat = mesh.plotSlice(Lpout,
ax=ax,
normal='Z',
ind=-27,
clim=(vmin, vmax),
pcolorOpts={'cmap': 'bwr'})
plt.plot(np.array([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
np.array([mesh.vectorCCy[yslice], mesh.vectorCCy[yslice]]),
c='gray',
linestyle='--')
plt.scatter(rxLoc[0:, 0], rxLoc[0:, 1], color='k', s=1)
plt.title('Z: ' + str(mesh.vectorCCz[-27]) + ' m')
plt.xlabel('Easting (m)')
plt.ylabel('Northing (m)')
plt.gca().set_aspect('equal', adjustable='box')
cb = plt.colorbar(dat[0],
orientation="vertical",
ticks=np.linspace(vmin, vmax, 4))
cb.set_label('Density (g/cc$^3$)')
ax = plt.subplot(212)
dat = mesh.plotSlice(Lpout,
ax=ax,
normal='Y',
ind=yslice,
clim=(vmin, vmax),
pcolorOpts={'cmap': 'bwr'})
plt.title('Cross Section')
plt.xlabel('Easting (m)')
plt.ylabel('Elevation (m)')
plt.gca().set_aspect('equal', adjustable='box')
cb = plt.colorbar(dat[0],
orientation="vertical",
ticks=np.linspace(vmin, vmax, 4))
cb.set_label('Density (g/cc$^3$)')
def run(plotIt=True):
# Set up cylindrically symmetric mesh
cs, ncx, ncz, npad = 10., 15, 25, 13 # padded cylindrical 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
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(
("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)
plt.tight_layout(pad=1.5)
def run(plotIt=True):
"""
EM: FDEM: 1D: Inversion
=======================
Here we will create and run a FDEM 1D inversion.
"""
cs, ncx, ncz, npad = 5., 25, 15, 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')
layerz = -100.
active = mesh.vectorCCz < 0.
layer = (mesh.vectorCCz < 0.) & (mesh.vectorCCz >= layerz)
actMap = Maps.InjectActiveCells(mesh, active, np.log(1e-8), nC=mesh.nCz)
mapping = Maps.ExpMap(mesh) * Maps.SurjectVertical1D(mesh) * actMap
sig_half = 2e-2
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])
if plotIt:
import matplotlib.pyplot as plt
fig, ax = plt.subplots(1, 1, figsize=(3, 6))
plt.semilogx(sigma[active], mesh.vectorCCz[active])
ax.set_ylim(-500, 0)
ax.set_xlim(1e-3, 1e-1)
ax.set_xlabel('Conductivity (S/m)', fontsize=14)
ax.set_ylabel('Depth (m)', fontsize=14)
ax.grid(color='k', alpha=0.5, linestyle='dashed', linewidth=0.5)
rxOffset = 10.
bzi = EM.FDEM.Rx.Point_b(np.array([[rxOffset, 0., 1e-3]]), orientation='z',
component='imag')
freqs = np.logspace(1, 3, 10)
srcLoc = np.array([0., 0., 10.])
srcList = [EM.FDEM.Src.MagDipole([bzi], freq, srcLoc, orientation='Z')
for freq in freqs]
survey = EM.FDEM.Survey(srcList)
prb = EM.FDEM.Problem3D_b(mesh, mapping=mapping)
try:
from pymatsolver import PardisoSolver
prb.Solver = PardisoSolver
except ImportError:
prb.Solver = SolverLU
prb.pair(survey)
std = 0.05
survey.makeSyntheticData(mtrue, std)
survey.std = std
survey.eps = np.linalg.norm(survey.dtrue)*1e-5
if plotIt:
import matplotlib.pyplot as plt
fig, ax = plt.subplots(1, 1, figsize = (6, 6))
ax.semilogx(freqs, survey.dtrue[:freqs.size], 'b.-')
ax.semilogx(freqs, survey.dobs[:freqs.size], 'r.-')
ax.legend(('Noisefree', '$d^{obs}$'), fontsize = 16)
ax.set_xlabel('Time (s)', fontsize=14)
ax.set_ylabel('$B_z$ (T)', fontsize=16)
ax.set_xlabel('Time (s)', fontsize=14)
ax.grid(color='k', alpha=0.5, linestyle='dashed', linewidth=0.5)
dmisfit = DataMisfit.l2_DataMisfit(survey)
regMesh = Mesh.TensorMesh([mesh.hz[mapping.maps[-1].indActive]])
reg = Regularization.Tikhonov(regMesh)
opt = Optimization.InexactGaussNewton(maxIter=6)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
# Create an inversion object
beta = Directives.BetaSchedule(coolingFactor=5, coolingRate=2)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1e0)
inv = Inversion.BaseInversion(invProb, directiveList=[beta, betaest])
m0 = np.log(np.ones(mtrue.size)*sig_half)
reg.alpha_s = 1e-3
reg.alpha_x = 1.
prb.counter = opt.counter = Utils.Counter()
opt.LSshorten = 0.5
opt.remember('xc')
mopt = inv.run(m0)
if plotIt:
import matplotlib.pyplot as plt
fig, ax = plt.subplots(1, 1, figsize=(3, 6))
plt.semilogx(sigma[active], mesh.vectorCCz[active])
plt.semilogx(np.exp(mopt), mesh.vectorCCz[active])
ax.set_ylim(-500, 0)
ax.set_xlim(1e-3, 1e-1)
ax.set_xlabel('Conductivity (S/m)', fontsize=14)
ax.set_ylabel('Depth (m)', fontsize=14)
ax.grid(color='k', alpha=0.5, linestyle='dashed', linewidth=0.5)
plt.legend(['$\sigma_{true}$', '$\sigma_{pred}$'], loc='best')
plt.show()
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, mapping=Maps.IdentityMap(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, mapping=Maps.IdentityMap(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()
resolve.close()
skytem.close()
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=True,
alpha_s=1e-4,
alpha_x=1.,
alpha_y=1.,
alpha_z=1.,
):
"""
Run DC 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.Simple(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.Tikhonov(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
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
update_Jacobi = Directives.UpdatePreconditioner()
if use_sensitivity_weight:
updateSensW = Directives.UpdateSensitivityWeights()
directiveList = [
beta, betaest, target, updateSensW, update_Jacobi
]
else:
directiveList = [
beta, betaest, target, update_Jacobi
]
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, cleanAfterRun=True):
# Start by downloading files from the remote repository
# directory where the downloaded files are
url = "https://storage.googleapis.com/simpeg/Chile_GRAV_4_Miller/Chile_GRAV_4_Miller.tar.gz"
downloads = download(url, overwrite=True)
basePath = downloads.split(".")[0]
# unzip the tarfile
tar = tarfile.open(downloads, "r")
tar.extractall()
tar.close()
input_file = basePath + os.path.sep + 'LdM_input_file.inp'
# %% User input
# Plotting parameters, max and min densities in g/cc
vmin = -0.6
vmax = 0.6
# weight exponent for default weighting
wgtexp = 3.
# %%
# Read in the input file which included all parameters at once
# (mesh, topo, model, survey, inv param, etc.)
driver = PF.GravityDriver.GravityDriver_Inv(input_file)
# %%
# Now we need to create the survey and model information.
# Access the mesh and survey information
mesh = driver.mesh
survey = driver.survey
# define gravity survey locations
rxLoc = survey.srcField.rxList[0].locs
# define gravity data and errors
d = survey.dobs
wd = survey.std
# Get the active cells
active = driver.activeCells
nC = len(active) # Number of active cells
# Create active map to go from reduce set to full
activeMap = Maps.InjectActiveCells(mesh, active, -100)
# Create static map
static = driver.staticCells
dynamic = driver.dynamicCells
staticCells = Maps.InjectActiveCells(
None, dynamic, driver.m0[static], nC=nC
)
mstart = driver.m0[dynamic]
# Get index of the center
midx = int(mesh.nCx/2)
# %%
# Now that we have a model and a survey we can build the linear system ...
# Create the forward model operator
prob = PF.Gravity.GravityIntegral(mesh, rhoMap=staticCells,
actInd=active)
prob.solverOpts['accuracyTol'] = 1e-4
# Pair the survey and problem
survey.pair(prob)
# Apply depth weighting
wr = PF.Magnetics.get_dist_wgt(mesh, rxLoc, active, wgtexp,
np.min(mesh.hx)/4.)
wr = wr**2.
# %% Create inversion objects
reg = Regularization.Sparse(mesh, indActive=active,
mapping=staticCells)
reg.mref = driver.mref[dynamic]
reg.cell_weights = wr * mesh.vol[active]
reg.norms = driver.lpnorms
# Specify how the optimization will proceed
opt = Optimization.ProjectedGNCG(maxIter=150, lower=driver.bounds[0],
upper=driver.bounds[1], maxIterLS=20,
maxIterCG=20, tolCG=1e-3)
# Define misfit function (obs-calc)
dmis = DataMisfit.l2_DataMisfit(survey)
dmis.W = 1./wd
# 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()
# IRLS sets up the Lp inversion problem
# Set the eps parameter parameter in Line 11 of the
# input file based on the distribution of model (DEFAULT = 95th %ile)
IRLS = Directives.Update_IRLS(f_min_change=1e-2, maxIRLSiter=20,
minGNiter=5)
# Preconditioning refreshing for each IRLS iteration
update_Jacobi = Directives.Update_lin_PreCond()
# Create combined the L2 and Lp problem
inv = Inversion.BaseInversion(invProb,
directiveList=[IRLS, update_Jacobi, betaest])
# %%
# Run L2 and Lp inversion
mrec = inv.run(mstart)
if cleanAfterRun:
os.remove(downloads)
shutil.rmtree(basePath)
# %%
if plotIt:
# Plot observed data
PF.Magnetics.plot_obs_2D(rxLoc, d, 'Observed Data')
# %%
# Write output model and data files and print misft stats.
# reconstructing l2 model mesh with air cells and active dynamic cells
L2out = activeMap * IRLS.l2model
# reconstructing lp model mesh with air cells and active dynamic cells
Lpout = activeMap*mrec
# %%
# Plot out sections and histograms of the smooth l2 model.
# The ind= parameter is the slice of the model from top down.
yslice = midx + 1
L2out[L2out == -100] = np.nan # set "air" to nan
plt.figure(figsize=(10, 7))
plt.suptitle('Smooth Inversion: Depth weight = ' + str(wgtexp))
ax = plt.subplot(221)
dat1 = mesh.plotSlice(L2out, ax=ax, normal='Z', ind=-16,
clim=(vmin, vmax), pcolorOpts={'cmap': 'bwr'})
plt.plot(np.array([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
np.array([mesh.vectorCCy[yslice], mesh.vectorCCy[yslice]]),
c='gray', linestyle='--')
plt.scatter(rxLoc[0:, 0], rxLoc[0:, 1], color='k', s=1)
plt.title('Z: ' + str(mesh.vectorCCz[-16]) + ' m')
plt.xlabel('Easting (m)')
plt.ylabel('Northing (m)')
plt.gca().set_aspect('equal', adjustable='box')
cb = plt.colorbar(dat1[0], orientation="vertical",
ticks=np.linspace(vmin, vmax, 4))
cb.set_label('Density (g/cc$^3$)')
ax = plt.subplot(222)
dat = mesh.plotSlice(L2out, ax=ax, normal='Z', ind=-27,
clim=(vmin, vmax), pcolorOpts={'cmap': 'bwr'})
plt.plot(np.array([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
np.array([mesh.vectorCCy[yslice], mesh.vectorCCy[yslice]]),
c='gray', linestyle='--')
plt.scatter(rxLoc[0:, 0], rxLoc[0:, 1], color='k', s=1)
plt.title('Z: ' + str(mesh.vectorCCz[-27]) + ' m')
plt.xlabel('Easting (m)')
plt.ylabel('Northing (m)')
plt.gca().set_aspect('equal', adjustable='box')
cb = plt.colorbar(dat1[0], orientation="vertical",
ticks=np.linspace(vmin, vmax, 4))
cb.set_label('Density (g/cc$^3$)')
ax = plt.subplot(212)
mesh.plotSlice(L2out, ax=ax, normal='Y', ind=yslice,
clim=(vmin, vmax), pcolorOpts={'cmap': 'bwr'})
plt.title('Cross Section')
plt.xlabel('Easting(m)')
plt.ylabel('Elevation')
plt.gca().set_aspect('equal', adjustable='box')
cb = plt.colorbar(dat1[0], orientation="vertical",
ticks=np.linspace(vmin, vmax, 4), cmap='bwr')
cb.set_label('Density (g/cc$^3$)')
# %%
# Make plots of Lp model
yslice = midx + 1
Lpout[Lpout == -100] = np.nan # set "air" to nan
plt.figure(figsize=(10, 7))
plt.suptitle('Compact Inversion: Depth weight = ' + str(wgtexp) +
': $\epsilon_p$ = ' + str(round(reg.eps_p, 1)) +
': $\epsilon_q$ = ' + str(round(reg.eps_q, 2)))
ax = plt.subplot(221)
dat = mesh.plotSlice(Lpout, ax=ax, normal='Z', ind=-16,
clim=(vmin, vmax), pcolorOpts={'cmap': 'bwr'})
plt.plot(np.array([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
np.array([mesh.vectorCCy[yslice], mesh.vectorCCy[yslice]]),
c='gray', linestyle='--')
plt.scatter(rxLoc[0:, 0], rxLoc[0:, 1], color='k', s=1)
plt.title('Z: ' + str(mesh.vectorCCz[-16]) + ' m')
plt.xlabel('Easting (m)')
plt.ylabel('Northing (m)')
plt.gca().set_aspect('equal', adjustable='box')
cb = plt.colorbar(dat[0], orientation="vertical",
ticks=np.linspace(vmin, vmax, 4))
cb.set_label('Density (g/cc$^3$)')
ax = plt.subplot(222)
dat = mesh.plotSlice(Lpout, ax=ax, normal='Z', ind=-27,
clim=(vmin, vmax), pcolorOpts={'cmap': 'bwr'})
plt.plot(np.array([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
np.array([mesh.vectorCCy[yslice], mesh.vectorCCy[yslice]]),
c='gray', linestyle='--')
plt.scatter(rxLoc[0:, 0], rxLoc[0:, 1], color='k', s=1)
plt.title('Z: ' + str(mesh.vectorCCz[-27]) + ' m')
plt.xlabel('Easting (m)')
plt.ylabel('Northing (m)')
plt.gca().set_aspect('equal', adjustable='box')
cb = plt.colorbar(dat[0], orientation="vertical",
ticks=np.linspace(vmin, vmax, 4))
cb.set_label('Density (g/cc$^3$)')
ax = plt.subplot(212)
dat = mesh.plotSlice(Lpout, ax=ax, normal='Y', ind=yslice,
clim=(vmin, vmax), pcolorOpts={'cmap': 'bwr'})
plt.title('Cross Section')
plt.xlabel('Easting (m)')
plt.ylabel('Elevation (m)')
plt.gca().set_aspect('equal', adjustable='box')
cb = plt.colorbar(dat[0], orientation="vertical",
ticks=np.linspace(vmin, vmax, 4))
cb.set_label('Density (g/cc$^3$)')
def run(plotIt=True):
# Create a mesh
dx = 5.
hxind = [(dx, 5, -1.3), (dx, 15), (dx, 5, 1.3)]
hyind = [(dx, 5, -1.3), (dx, 15), (dx, 5, 1.3)]
hzind = [(dx, 5, -1.3), (dx, 7), (3.5, 1), (2, 5)]
mesh = Mesh.TensorMesh([hxind, hyind, hzind], 'CCC')
# Get index of the center
midx = int(mesh.nCx/2)
midy = int(mesh.nCy/2)
# Lets create a simple Gaussian topo and set the active cells
[xx, yy] = np.meshgrid(mesh.vectorNx, mesh.vectorNy)
zz = -np.exp((xx**2 + yy**2) / 75**2) + mesh.vectorNz[-1]
# We would usually load a topofile
topo = np.c_[Utils.mkvc(xx), Utils.mkvc(yy), Utils.mkvc(zz)]
# Go from topo to array of indices of active cells
actv = Utils.surface2ind_topo(mesh, topo, 'N')
actv = np.where(actv)[0]
nC = len(actv)
# Create and array of observation points
xr = np.linspace(-30., 30., 20)
yr = np.linspace(-30., 30., 20)
X, Y = np.meshgrid(xr, yr)
# Move the observation points 5m above the topo
Z = -np.exp((X**2 + Y**2) / 75**2) + mesh.vectorNz[-1] + 0.1
# Create a GRAVsurvey
rxLoc = np.c_[Utils.mkvc(X.T), Utils.mkvc(Y.T), Utils.mkvc(Z.T)]
rxLoc = PF.BaseGrav.RxObs(rxLoc)
srcField = PF.BaseGrav.SrcField([rxLoc])
survey = PF.BaseGrav.LinearSurvey(srcField)
# We can now create a density model and generate data
# Here a simple block in half-space
model = np.zeros((mesh.nCx, mesh.nCy, mesh.nCz))
model[(midx-5):(midx-1), (midy-2):(midy+2), -10:-6] = 0.75
model[(midx+1):(midx+5), (midy-2):(midy+2), -10:-6] = -0.75
model = Utils.mkvc(model)
model = model[actv]
# Create active map to go from reduce set to full
actvMap = Maps.InjectActiveCells(mesh, actv, -100)
# Create reduced identity map
idenMap = Maps.IdentityMap(nP=nC)
# Create the forward model operator
prob = PF.Gravity.GravityIntegral(mesh, rhoMap=idenMap, actInd=actv)
# Pair the survey and problem
survey.pair(prob)
# Compute linear forward operator and compute some data
d = prob.fields(model)
# Add noise and uncertainties
# We add some random Gaussian noise (1nT)
data = d + np.random.randn(len(d))*1e-3
wd = np.ones(len(data))*1e-3 # Assign flat uncertainties
survey.dobs = data
survey.std = wd
survey.mtrue = model
# Create sensitivity weights from our linear forward operator
rxLoc = survey.srcField.rxList[0].locs
wr = np.sum(prob.G**2., axis=0)**0.5
wr = (wr/np.max(wr))
# Create a regularization
reg = Regularization.Sparse(mesh, indActive=actv, mapping=idenMap)
reg.cell_weights = wr
reg.norms = np.c_[0, 0, 0, 0]
# Data misfit function
dmis = DataMisfit.l2_DataMisfit(survey)
dmis.W = Utils.sdiag(1/wd)
# Add directives to the inversion
opt = Optimization.ProjectedGNCG(maxIter=100, lower=-1., upper=1.,
maxIterLS=20, maxIterCG=10,
tolCG=1e-3)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1e-1)
# Here is where the norms are applied
# Use pick a threshold parameter empirically based on the distribution of
# model parameters
IRLS = Directives.Update_IRLS(
f_min_change=1e-4, maxIRLSiter=30, coolEpsFact=1.5, beta_tol=1e-1,
)
saveDict = Directives.SaveOutputEveryIteration(save_txt=False)
update_Jacobi = Directives.UpdatePreconditioner()
inv = Inversion.BaseInversion(
invProb, directiveList=[IRLS, betaest, update_Jacobi, saveDict]
)
# Run the inversion
m0 = np.ones(nC)*1e-4 # Starting model
mrec = inv.run(m0)
if plotIt:
# Here is the recovered susceptibility model
ypanel = midx
zpanel = -7
m_l2 = actvMap * invProb.l2model
m_l2[m_l2 == -100] = np.nan
m_lp = actvMap * mrec
m_lp[m_lp == -100] = np.nan
m_true = actvMap * model
m_true[m_true == -100] = np.nan
vmin, vmax = mrec.min(), mrec.max()
# Plot the data
Utils.PlotUtils.plot2Ddata(rxLoc, data)
plt.figure()
# Plot L2 model
ax = plt.subplot(321)
mesh.plotSlice(m_l2, ax=ax, normal='Z', ind=zpanel,
grid=True, clim=(vmin, vmax))
plt.plot(([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
([mesh.vectorCCy[ypanel], mesh.vectorCCy[ypanel]]), color='w')
plt.title('Plan l2-model.')
plt.gca().set_aspect('equal')
plt.ylabel('y')
ax.xaxis.set_visible(False)
plt.gca().set_aspect('equal', adjustable='box')
# Vertical section
ax = plt.subplot(322)
mesh.plotSlice(m_l2, ax=ax, normal='Y', ind=midx,
grid=True, clim=(vmin, vmax))
plt.plot(([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
([mesh.vectorCCz[zpanel], mesh.vectorCCz[zpanel]]), color='w')
plt.title('E-W l2-model.')
plt.gca().set_aspect('equal')
ax.xaxis.set_visible(False)
plt.ylabel('z')
plt.gca().set_aspect('equal', adjustable='box')
# Plot Lp model
ax = plt.subplot(323)
mesh.plotSlice(m_lp, ax=ax, normal='Z', ind=zpanel,
grid=True, clim=(vmin, vmax))
plt.plot(([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
([mesh.vectorCCy[ypanel], mesh.vectorCCy[ypanel]]), color='w')
plt.title('Plan lp-model.')
plt.gca().set_aspect('equal')
ax.xaxis.set_visible(False)
plt.ylabel('y')
plt.gca().set_aspect('equal', adjustable='box')
# Vertical section
ax = plt.subplot(324)
mesh.plotSlice(m_lp, ax=ax, normal='Y', ind=midx,
grid=True, clim=(vmin, vmax))
plt.plot(([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
([mesh.vectorCCz[zpanel], mesh.vectorCCz[zpanel]]), color='w')
plt.title('E-W lp-model.')
plt.gca().set_aspect('equal')
ax.xaxis.set_visible(False)
plt.ylabel('z')
plt.gca().set_aspect('equal', adjustable='box')
# Plot True model
ax = plt.subplot(325)
mesh.plotSlice(m_true, ax=ax, normal='Z', ind=zpanel,
grid=True, clim=(vmin, vmax))
plt.plot(([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
([mesh.vectorCCy[ypanel], mesh.vectorCCy[ypanel]]), color='w')
plt.title('Plan true model.')
plt.gca().set_aspect('equal')
plt.xlabel('x')
plt.ylabel('y')
plt.gca().set_aspect('equal', adjustable='box')
# Vertical section
ax = plt.subplot(326)
mesh.plotSlice(m_true, ax=ax, normal='Y', ind=midx,
grid=True, clim=(vmin, vmax))
plt.plot(([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
([mesh.vectorCCz[zpanel], mesh.vectorCCz[zpanel]]), color='w')
plt.title('E-W true model.')
plt.gca().set_aspect('equal')
plt.xlabel('x')
plt.ylabel('z')
plt.gca().set_aspect('equal', adjustable='box')
# Plot convergence curves
fig, axs = plt.figure(), plt.subplot()
axs.plot(saveDict.phi_d, 'k', lw=2)
axs.plot(
np.r_[IRLS.iterStart, IRLS.iterStart],
np.r_[0, np.max(saveDict.phi_d)], 'k:'
)
twin = axs.twinx()
twin.plot(saveDict.phi_m, 'k--', lw=2)
axs.text(
IRLS.iterStart, np.max(saveDict.phi_d)/2.,
'IRLS Steps', va='bottom', ha='center',
rotation='vertical', size=12,
bbox={'facecolor': 'white'}
)
axs.set_ylabel('$\phi_d$', size=16, rotation=0)
axs.set_xlabel('Iterations', size=14)
twin.set_ylabel('$\phi_m$', size=16, rotation=0)
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(plotIt=True):
"""
1D FDEM and TDEM inversions
===========================
This example is used in the paper Heagy et al 2016 (in prep)
"""
# 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.]])
bzi = FDEM.Rx.Point_bSecondary(rxlocs, 'z', 'real')
bzr = 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 = []
[srcList.append(FDEM.Src.MagDipole([bzr, bzi], freq, srcLoc,
orientation='Z')) for freq in freqs]
surveyFD = FDEM.Survey(srcList)
prbFD = FDEM.Problem3D_b(mesh, mapping=mapping)
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()
inv = Inversion.BaseInversion(invProb, directiveList=[beta, betaest, target])
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(rxlocs, times, 'bz')
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, mapping=mapping)
prbTD.timeSteps = [(5e-5, 10), (1e-4, 10), (5e-4, 10)]
prbTD.pair(surveyTD)
prbTD.Solver = SolverLU
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)
# Inversion Directives
beta = Directives.BetaSchedule(coolingFactor=4, coolingRate=3)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=2.)
target = Directives.TargetMisfit()
inv = Inversion.BaseInversion(invProb, directiveList=[beta, betaest, target])
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)
if plotIt:
import matplotlib
fig = 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)
ax0.semilogx(np.exp(moptFD), mesh.vectorCCz[active], 'bo', ms=6)
ax0.semilogx(np.exp(moptTD), mesh.vectorCCz[active], 'r*', ms=10)
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(['True', 'FDEM', 'TDEM'], 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)
ax1.plot(freqs, -surveyFD.dobs[1::2], 'k--', lw=2)
dpredFD = surveyFD.dpred(moptTD)
ax1.loglog(freqs, -dpredFD[::2], 'bo', ms=6)
ax1.loglog(freqs, -dpredFD[1::2], 'b+', markeredgewidth=2., ms=10)
ax2.loglog(times, surveyTD.dobs, 'k-', lw=2)
ax2.loglog(times, surveyTD.dpred(moptTD), 'r*', ms=10)
ax2.set_xlim(times.min(), times.max())
# 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(("Obs", "Pred"), fontsize=fs)
ax1.legend(("Obs (real)", "Obs (imag)", "Pred (real)", "Pred (imag)"),
fontsize=fs)
ax1.set_xlim(freqs.max(), freqs.min())
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)
plt.show()
def run(plotIt=True):
cs, ncx, ncz, npad = 5., 25, 15, 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')
layerz = -100.
active = mesh.vectorCCz < 0.
layer = (mesh.vectorCCz < 0.) & (mesh.vectorCCz >= layerz)
actMap = Maps.InjectActiveCells(mesh, active, np.log(1e-8), nC=mesh.nCz)
mapping = Maps.ExpMap(mesh) * Maps.SurjectVertical1D(mesh) * actMap
sig_half = 2e-2
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])
if plotIt:
fig, ax = plt.subplots(1, 1, figsize=(3, 6))
plt.semilogx(sigma[active], mesh.vectorCCz[active])
ax.set_ylim(-500, 0)
ax.set_xlim(1e-3, 1e-1)
ax.set_xlabel('Conductivity (S/m)', fontsize=14)
ax.set_ylabel('Depth (m)', fontsize=14)
ax.grid(color='k', alpha=0.5, linestyle='dashed', linewidth=0.5)
rxOffset = 10.
bzi = EM.FDEM.Rx.Point_b(np.array([[rxOffset, 0., 1e-3]]),
orientation='z',
component='imag')
freqs = np.logspace(1, 3, 10)
srcLoc = np.array([0., 0., 10.])
srcList = [
EM.FDEM.Src.MagDipole([bzi], freq, srcLoc, orientation='Z')
for freq in freqs
]
survey = EM.FDEM.Survey(srcList)
prb = EM.FDEM.Problem3D_b(mesh, sigmaMap=mapping, Solver=Solver)
prb.pair(survey)
std = 0.05
survey.makeSyntheticData(mtrue, std)
survey.std = std
survey.eps = np.linalg.norm(survey.dtrue) * 1e-5
if plotIt:
fig, ax = plt.subplots(1, 1, figsize=(6, 6))
ax.semilogx(freqs, survey.dtrue[:freqs.size], 'b.-')
ax.semilogx(freqs, survey.dobs[:freqs.size], 'r.-')
ax.legend(('Noisefree', '$d^{obs}$'), fontsize=16)
ax.set_xlabel('Time (s)', fontsize=14)
ax.set_ylabel('$B_z$ (T)', fontsize=16)
ax.set_xlabel('Time (s)', fontsize=14)
ax.grid(color='k', alpha=0.5, linestyle='dashed', linewidth=0.5)
dmisfit = DataMisfit.l2_DataMisfit(survey)
regMesh = Mesh.TensorMesh([mesh.hz[mapping.maps[-1].indActive]])
reg = Regularization.Tikhonov(regMesh)
opt = Optimization.InexactGaussNewton(maxIter=6)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
# Create an inversion object
beta = Directives.BetaSchedule(coolingFactor=5, coolingRate=2)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1e0)
inv = Inversion.BaseInversion(invProb, directiveList=[beta, betaest])
m0 = np.log(np.ones(mtrue.size) * sig_half)
reg.alpha_s = 1e-3
reg.alpha_x = 1.
prb.counter = opt.counter = Utils.Counter()
opt.LSshorten = 0.5
opt.remember('xc')
mopt = inv.run(m0)
if plotIt:
fig, ax = plt.subplots(1, 1, figsize=(3, 6))
plt.semilogx(sigma[active], mesh.vectorCCz[active])
plt.semilogx(np.exp(mopt), mesh.vectorCCz[active])
ax.set_ylim(-500, 0)
ax.set_xlim(1e-3, 1e-1)
ax.set_xlabel('Conductivity (S/m)', fontsize=14)
ax.set_ylabel('Depth (m)', fontsize=14)
ax.grid(color='k', alpha=0.5, linestyle='dashed', linewidth=0.5)
plt.legend(['$\sigma_{true}$', '$\sigma_{pred}$'], loc='best')
def setUp(self):
ndv = -100
# Create a self.mesh
dx = 5.
hxind = [(dx, 5, -1.3), (dx, 5), (dx, 5, 1.3)]
hyind = [(dx, 5, -1.3), (dx, 5), (dx, 5, 1.3)]
hzind = [(dx, 5, -1.3), (dx, 6)]
self.mesh = Mesh.TensorMesh([hxind, hyind, hzind], 'CCC')
# Get index of the center
midx = int(self.mesh.nCx/2)
midy = int(self.mesh.nCy/2)
# Lets create a simple Gaussian topo and set the active cells
[xx, yy] = np.meshgrid(self.mesh.vectorNx, self.mesh.vectorNy)
zz = -np.exp((xx**2 + yy**2) / 75**2) + self.mesh.vectorNz[-1]
# Go from topo to actv cells
topo = np.c_[Utils.mkvc(xx), Utils.mkvc(yy), Utils.mkvc(zz)]
actv = Utils.surface2ind_topo(self.mesh, topo, 'N')
actv = np.where(actv)[0]
# Create active map to go from reduce space to full
self.actvMap = Maps.InjectActiveCells(self.mesh, actv, -100)
nC = len(actv)
# Create and array of observation points
xr = np.linspace(-20., 20., 20)
yr = np.linspace(-20., 20., 20)
X, Y = np.meshgrid(xr, yr)
# Move the observation points 5m above the topo
Z = -np.exp((X**2 + Y**2) / 75**2) + self.mesh.vectorNz[-1] + 5.
# Create a MAGsurvey
locXYZ = np.c_[Utils.mkvc(X.T), Utils.mkvc(Y.T), Utils.mkvc(Z.T)]
rxLoc = PF.BaseGrav.RxObs(locXYZ)
srcField = PF.BaseGrav.SrcField([rxLoc])
survey = PF.BaseGrav.LinearSurvey(srcField)
# We can now create a density model and generate data
# Here a simple block in half-space
model = np.zeros((self.mesh.nCx, self.mesh.nCy, self.mesh.nCz))
model[(midx-2):(midx+2), (midy-2):(midy+2), -6:-2] = 0.5
model = Utils.mkvc(model)
self.model = model[actv]
# Create active map to go from reduce set to full
actvMap = Maps.InjectActiveCells(self.mesh, actv, ndv)
# Create reduced identity map
idenMap = Maps.IdentityMap(nP=nC)
# Create the forward model operator
prob = PF.Gravity.GravityIntegral(
self.mesh,
rhoMap=idenMap,
actInd=actv
)
# Pair the survey and problem
survey.pair(prob)
# Compute linear forward operator and compute some data
d = prob.fields(self.model)
# Add noise and uncertainties (1nT)
data = d + np.random.randn(len(d))*0.001
wd = np.ones(len(data))*.001
survey.dobs = data
survey.std = wd
# PF.Gravity.plot_obs_2D(survey.srcField.rxList[0].locs, d=data)
# Create sensitivity weights from our linear forward operator
wr = PF.Magnetics.get_dist_wgt(self.mesh, locXYZ, actv, 2., 2.)
wr = wr**2.
# Create a regularization
reg = Regularization.Sparse(self.mesh, indActive=actv, mapping=idenMap)
reg.cell_weights = wr
reg.norms = np.c_[0, 0, 0, 0]
reg.gradientType = 'component'
# reg.eps_p, reg.eps_q = 5e-2, 1e-2
# Data misfit function
dmis = DataMisfit.l2_DataMisfit(survey)
dmis.W = 1/wd
# Add directives to the inversion
opt = Optimization.ProjectedGNCG(maxIter=100, lower=-1., upper=1.,
maxIterLS=20, maxIterCG=10,
tolCG=1e-3)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=1e+8)
# Here is where the norms are applied
IRLS = Directives.Update_IRLS(f_min_change=1e-4,
minGNiter=1)
update_Jacobi = Directives.UpdatePreconditioner()
self.inv = Inversion.BaseInversion(invProb,
directiveList=[IRLS,
update_Jacobi])
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):
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(['$\sigma_{true}$', '$\sigma_{pred}$'])
prob.solverOpts['accuracyTol'] = 1e-4
# Pair the survey and problem
survey.pair(prob)
# Create a regularization function, in this case l2l2
reg = Regularization.Simple(mesh, indActive=surf)
reg.mref = np.zeros(nC)
# Specify how the optimization will proceed, set susceptibility bounds to inf
opt = Optimization.ProjectedGNCG(maxIter=25, lower=-np.inf,
upper=np.inf, maxIterLS=20,
maxIterCG=20, tolCG=1e-3)
# 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)
def run(plotIt=True):
"""
EM: TDEM: 1D: Inversion
=======================
Here we will create and run a TDEM 1D inversion.
"""
cs, ncx, ncz, npad = 5., 25, 15, 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 < 0.) & (mesh.vectorCCz >= -100.)
actMap = Maps.InjectActiveCells(mesh, active, np.log(1e-8), nC=mesh.nCz)
mapping = Maps.ExpMap(mesh) * Maps.SurjectVertical1D(mesh) * actMap
sig_half = 2e-3
sig_air = 1e-8
sig_layer = 1e-3
sigma = np.ones(mesh.nCz)*sig_air
sigma[active] = sig_half
sigma[layer] = sig_layer
mtrue = np.log(sigma[active])
if plotIt is True:
import matplotlib.pyplot as plt
fig, ax = plt.subplots(1, 1, figsize=(3, 6))
plt.semilogx(sigma[active], mesh.vectorCCz[active])
ax.set_ylim(-600, 0)
ax.set_xlim(1e-4, 1e-2)
ax.set_xlabel('Conductivity (S/m)', fontsize=14)
ax.set_ylabel('Depth (m)', fontsize=14)
ax.grid(color='k', alpha=0.5, linestyle='dashed', linewidth=0.5)
rxOffset = 1e-3
rx = EM.TDEM.Rx(np.array([[rxOffset, 0., 30]]),
np.logspace(-5, -3, 31), 'bz')
src = EM.TDEM.Src.MagDipole([rx], loc=np.array([0., 0., 80]))
survey = EM.TDEM.Survey([src])
prb = EM.TDEM.Problem3D_b(mesh, mapping=mapping)
prb.Solver = SolverLU
prb.timeSteps = [(1e-06, 20), (1e-05, 20), (0.0001, 20)]
prb.pair(survey)
# create observed data
std = 0.05
survey.dobs = survey.makeSyntheticData(mtrue, std)
survey.std = std
survey.eps = 1e-5*np.linalg.norm(survey.dobs)
if plotIt:
import matplotlib.pyplot as plt
fig, ax = plt.subplots(1, 1, figsize = (10, 6))
ax.loglog(rx.times, survey.dtrue, 'b.-')
ax.loglog(rx.times, survey.dobs, 'r.-')
ax.legend(('Noisefree', '$d^{obs}$'), fontsize=16)
ax.set_xlabel('Time (s)', fontsize=14)
ax.set_ylabel('$B_z$ (T)', fontsize=16)
ax.set_xlabel('Time (s)', fontsize=14)
ax.grid(color='k', alpha=0.5, linestyle='dashed', linewidth=0.5)
dmisfit = DataMisfit.l2_DataMisfit(survey)
regMesh = Mesh.TensorMesh([mesh.hz[mapping.maps[-1].indActive]])
reg = Regularization.Tikhonov(regMesh)
opt = Optimization.InexactGaussNewton(maxIter=5)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
# Create an inversion object
beta = Directives.BetaSchedule(coolingFactor=5, coolingRate=2)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1e0)
inv = Inversion.BaseInversion(invProb, directiveList=[beta, betaest])
m0 = np.log(np.ones(mtrue.size)*sig_half)
reg.alpha_s = 1e-2
reg.alpha_x = 1.
prb.counter = opt.counter = Utils.Counter()
opt.LSshorten = 0.5
opt.remember('xc')
mopt = inv.run(m0)
if plotIt:
import matplotlib.pyplot as plt
fig, ax = plt.subplots(1, 1, figsize=(3, 6))
plt.semilogx(sigma[active], mesh.vectorCCz[active])
plt.semilogx(np.exp(mopt), mesh.vectorCCz[active])
ax.set_ylim(-600, 0)
ax.set_xlim(1e-4, 1e-2)
ax.set_xlabel('Conductivity (S/m)', fontsize=14)
ax.set_ylabel('Depth (m)', fontsize=14)
ax.grid(color='k', alpha=0.5, linestyle='dashed', linewidth=0.5)
plt.legend(['$\sigma_{true}$', '$\sigma_{pred}$'])
plt.show()
def setUp(self):
np.random.seed(0)
# Define the inducing field parameter
H0 = (50000, 90, 0)
# Create a mesh
dx = 5.
hxind = [(dx, 5, -1.3), (dx, 5), (dx, 5, 1.3)]
hyind = [(dx, 5, -1.3), (dx, 5), (dx, 5, 1.3)]
hzind = [(dx, 5, -1.3), (dx, 6)]
mesh = Mesh.TensorMesh([hxind, hyind, hzind], 'CCC')
# Get index of the center
midx = int(mesh.nCx / 2)
midy = int(mesh.nCy / 2)
# Lets create a simple Gaussian topo and set the active cells
[xx, yy] = np.meshgrid(mesh.vectorNx, mesh.vectorNy)
zz = -np.exp((xx**2 + yy**2) / 75**2) + mesh.vectorNz[-1]
# Go from topo to actv cells
topo = np.c_[Utils.mkvc(xx), Utils.mkvc(yy), Utils.mkvc(zz)]
actv = Utils.surface2ind_topo(mesh, topo, 'N')
actv = np.asarray([inds for inds, elem in enumerate(actv, 1) if elem],
dtype=int) - 1
# Create active map to go from reduce space to full
actvMap = Maps.InjectActiveCells(mesh, actv, -100)
nC = len(actv)
# Create and array of observation points
xr = np.linspace(-20., 20., 20)
yr = np.linspace(-20., 20., 20)
X, Y = np.meshgrid(xr, yr)
# Move the observation points 5m above the topo
Z = -np.exp((X**2 + Y**2) / 75**2) + mesh.vectorNz[-1] + 5.
# Create a MAGsurvey
rxLoc = np.c_[Utils.mkvc(X.T), Utils.mkvc(Y.T), Utils.mkvc(Z.T)]
rxLoc = PF.BaseMag.RxObs(rxLoc)
srcField = PF.BaseMag.SrcField([rxLoc], param=H0)
survey = PF.BaseMag.LinearSurvey(srcField)
# We can now create a susceptibility model and generate data
# Here a simple block in half-space
model = np.zeros((mesh.nCx, mesh.nCy, mesh.nCz))
model[(midx - 2):(midx + 2), (midy - 2):(midy + 2), -6:-2] = 0.02
model = Utils.mkvc(model)
self.model = model[actv]
# Create active map to go from reduce set to full
actvMap = Maps.InjectActiveCells(mesh, actv, -100)
# Creat reduced identity map
idenMap = Maps.IdentityMap(nP=nC)
# Create the forward model operator
prob = PF.Magnetics.MagneticIntegral(mesh, chiMap=idenMap, actInd=actv)
# Pair the survey and problem
survey.pair(prob)
# Compute linear forward operator and compute some data
d = prob.fields(self.model)
# Add noise and uncertainties (1nT)
data = d + np.random.randn(len(d))
wd = np.ones(len(data)) * 1.
survey.dobs = data
survey.std = wd
# Create sensitivity weights from our linear forward operator
wr = np.sum(prob.G**2., axis=0)**0.5
wr = (wr / np.max(wr))
# Create a regularization
reg = Regularization.Sparse(mesh, indActive=actv, mapping=idenMap)
reg.cell_weights = wr
reg.norms = np.c_[0, 0, 0, 0]
reg.gradientType = 'component'
# reg.eps_p, reg.eps_q = 1e-3, 1e-3
# Data misfit function
dmis = DataMisfit.l2_DataMisfit(survey)
dmis.W = 1 / wd
# Add directives to the inversion
opt = Optimization.ProjectedGNCG(maxIter=100,
lower=0.,
upper=1.,
maxIterLS=20,
maxIterCG=10,
tolCG=1e-3)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
betaest = Directives.BetaEstimate_ByEig()
# Here is where the norms are applied
IRLS = Directives.Update_IRLS(f_min_change=1e-4, minGNiter=1)
update_Jacobi = Directives.UpdatePreconditioner()
self.inv = Inversion.BaseInversion(
invProb, directiveList=[IRLS, betaest, update_Jacobi])
def setUp(self):
np.random.seed(0)
H0 = (50000., 90., 0.)
# The magnetization is set along a different
# direction (induced + remanence)
M = np.array([45., 90.])
# Create grid of points for topography
# Lets create a simple Gaussian topo
# and set the active cells
[xx, yy] = np.meshgrid(
np.linspace(-200, 200, 50),
np.linspace(-200, 200, 50)
)
b = 100
A = 50
zz = A*np.exp(-0.5*((xx/b)**2. + (yy/b)**2.))
# We would usually load a topofile
topo = np.c_[Utils.mkvc(xx), Utils.mkvc(yy), Utils.mkvc(zz)]
# Create and array of observation points
xr = np.linspace(-100., 100., 20)
yr = np.linspace(-100., 100., 20)
X, Y = np.meshgrid(xr, yr)
Z = A*np.exp(-0.5*((X/b)**2. + (Y/b)**2.)) + 5
# Create a MAGsurvey
xyzLoc = np.c_[Utils.mkvc(X.T), Utils.mkvc(Y.T), Utils.mkvc(Z.T)]
rxLoc = PF.BaseMag.RxObs(xyzLoc)
srcField = PF.BaseMag.SrcField([rxLoc], param=H0)
survey = PF.BaseMag.LinearSurvey(srcField)
# Create a mesh
h = [5, 5, 5]
padDist = np.ones((3, 2)) * 100
nCpad = [2, 4, 2]
# Get extent of points
limx = np.r_[topo[:, 0].max(), topo[:, 0].min()]
limy = np.r_[topo[:, 1].max(), topo[:, 1].min()]
limz = np.r_[topo[:, 2].max(), topo[:, 2].min()]
# Get center of the mesh
midX = np.mean(limx)
midY = np.mean(limy)
midZ = np.mean(limz)
nCx = int(limx[0]-limx[1]) / h[0]
nCy = int(limy[0]-limy[1]) / h[1]
nCz = int(limz[0]-limz[1]+int(np.min(np.r_[nCx, nCy])/3)) / h[2]
# Figure out full extent required from input
extent = np.max(np.r_[nCx * h[0] + padDist[0, :].sum(),
nCy * h[1] + padDist[1, :].sum(),
nCz * h[2] + padDist[2, :].sum()])
maxLevel = int(np.log2(extent/h[0]))+1
# Number of cells at the small octree level
nCx, nCy, nCz = 2**(maxLevel), 2**(maxLevel), 2**(maxLevel)
# Define the mesh and origin
# For now cubic cells
mesh = Mesh.TreeMesh([np.ones(nCx)*h[0],
np.ones(nCx)*h[1],
np.ones(nCx)*h[2]])
# Set origin
mesh.x0 = np.r_[
-nCx*h[0]/2.+midX,
-nCy*h[1]/2.+midY,
-nCz*h[2]/2.+midZ
]
# Refine the mesh around topography
# Get extent of points
F = NearestNDInterpolator(topo[:, :2], topo[:, 2])
zOffset = 0
# Cycle through the first 3 octree levels
for ii in range(3):
dx = mesh.hx.min()*2**ii
nCx = int((limx[0]-limx[1]) / dx)
nCy = int((limy[0]-limy[1]) / dx)
# Create a grid at the octree level in xy
CCx, CCy = np.meshgrid(
np.linspace(limx[1], limx[0], nCx),
np.linspace(limy[1], limy[0], nCy)
)
z = F(mkvc(CCx), mkvc(CCy))
# level means number of layers in current OcTree level
for level in range(int(nCpad[ii])):
mesh.insert_cells(
np.c_[
mkvc(CCx),
mkvc(CCy),
z-zOffset
], np.ones_like(z)*maxLevel-ii,
finalize=False
)
zOffset += dx
mesh.finalize()
self.mesh = mesh
# Define an active cells from topo
actv = Utils.surface2ind_topo(mesh, topo)
nC = int(actv.sum())
model = np.zeros((mesh.nC, 3))
# Convert the inclination declination to vector in Cartesian
M_xyz = Utils.matutils.dip_azimuth2cartesian(M[0], M[1])
# Get the indicies of the magnetized block
ind = Utils.ModelBuilder.getIndicesBlock(
np.r_[-20, -20, -10], np.r_[20, 20, 25],
mesh.gridCC,
)[0]
# Assign magnetization values
model[ind, :] = np.kron(
np.ones((ind.shape[0], 1)), M_xyz*0.05
)
# Remove air cells
self.model = model[actv, :]
# Create active map to go from reduce set to full
self.actvMap = Maps.InjectActiveCells(mesh, actv, np.nan)
# Creat reduced identity map
idenMap = Maps.IdentityMap(nP=nC*3)
# Create the forward model operator
prob = PF.Magnetics.MagneticIntegral(
mesh, chiMap=idenMap, actInd=actv,
modelType='vector'
)
# Pair the survey and problem
survey.pair(prob)
# Compute some data and add some random noise
data = prob.fields(Utils.mkvc(self.model))
std = 5 # nT
data += np.random.randn(len(data))*std
wd = np.ones(len(data))*std
# Assigne data and uncertainties to the survey
survey.dobs = data
survey.std = wd
# Create an projection matrix for plotting later
actvPlot = Maps.InjectActiveCells(mesh, actv, np.nan)
# Create sensitivity weights from our linear forward operator
rxLoc = survey.srcField.rxList[0].locs
# This Mapping connects the regularizations for the three-component
# vector model
wires = Maps.Wires(('p', nC), ('s', nC), ('t', nC))
# Create sensitivity weights from our linear forward operator
# so that all cells get equal chance to contribute to the solution
wr = np.sum(prob.G**2., axis=0)**0.5
wr = (wr/np.max(wr))
# Create three regularization for the different components
# of magnetization
reg_p = Regularization.Sparse(mesh, indActive=actv, mapping=wires.p)
reg_p.mref = np.zeros(3*nC)
reg_p.cell_weights = (wires.p * wr)
reg_s = Regularization.Sparse(mesh, indActive=actv, mapping=wires.s)
reg_s.mref = np.zeros(3*nC)
reg_s.cell_weights = (wires.s * wr)
reg_t = Regularization.Sparse(mesh, indActive=actv, mapping=wires.t)
reg_t.mref = np.zeros(3*nC)
reg_t.cell_weights = (wires.t * wr)
reg = reg_p + reg_s + reg_t
reg.mref = np.zeros(3*nC)
# Data misfit function
dmis = DataMisfit.l2_DataMisfit(survey)
dmis.W = 1./survey.std
# Add directives to the inversion
opt = Optimization.ProjectedGNCG(maxIter=30, lower=-10, upper=10.,
maxIterLS=20, maxIterCG=20, tolCG=1e-4)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
# A list of directive to control the inverson
betaest = Directives.BetaEstimate_ByEig()
# Here is where the norms are applied
# Use pick a treshold parameter empirically based on the distribution of
# model parameters
IRLS = Directives.Update_IRLS(
f_min_change=1e-3, maxIRLSiter=0, beta_tol=5e-1
)
# Pre-conditioner
update_Jacobi = Directives.UpdatePreconditioner()
inv = Inversion.BaseInversion(invProb,
directiveList=[IRLS, update_Jacobi, betaest])
# Run the inversion
m0 = np.ones(3*nC) * 1e-4 # Starting model
mrec_MVIC = inv.run(m0)
self.mstart = Utils.matutils.cartesian2spherical(mrec_MVIC.reshape((nC, 3), order='F'))
beta = invProb.beta
dmis.prob.coordinate_system = 'spherical'
dmis.prob.model = self.mstart
# Create a block diagonal regularization
wires = Maps.Wires(('amp', nC), ('theta', nC), ('phi', nC))
# Create a Combo Regularization
# Regularize the amplitude of the vectors
reg_a = Regularization.Sparse(mesh, indActive=actv,
mapping=wires.amp)
reg_a.norms = np.c_[0., 0., 0., 0.] # Sparse on the model and its gradients
reg_a.mref = np.zeros(3*nC)
# Regularize the vertical angle of the vectors
reg_t = Regularization.Sparse(mesh, indActive=actv,
mapping=wires.theta)
reg_t.alpha_s = 0. # No reference angle
reg_t.space = 'spherical'
reg_t.norms = np.c_[2., 0., 0., 0.] # Only norm on gradients used
# Regularize the horizontal angle of the vectors
reg_p = Regularization.Sparse(mesh, indActive=actv,
mapping=wires.phi)
reg_p.alpha_s = 0. # No reference angle
reg_p.space = 'spherical'
reg_p.norms = np.c_[2., 0., 0., 0.] # Only norm on gradients used
reg = reg_a + reg_t + reg_p
reg.mref = np.zeros(3*nC)
Lbound = np.kron(np.asarray([0, -np.inf, -np.inf]), np.ones(nC))
Ubound = np.kron(np.asarray([10, np.inf, np.inf]), np.ones(nC))
# Add directives to the inversion
opt = Optimization.ProjectedGNCG(maxIter=20,
lower=Lbound,
upper=Ubound,
maxIterLS=20,
maxIterCG=30,
tolCG=1e-3,
stepOffBoundsFact=1e-3,
)
opt.approxHinv = None
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=beta*10.)
# Here is where the norms are applied
IRLS = Directives.Update_IRLS(f_min_change=1e-4, maxIRLSiter=20,
minGNiter=1, beta_tol=0.5,
coolingRate=1, coolEps_q=True,
betaSearch=False)
# Special directive specific to the mag amplitude problem. The sensitivity
# weights are update between each iteration.
ProjSpherical = Directives.ProjectSphericalBounds()
update_SensWeight = Directives.UpdateSensitivityWeights()
update_Jacobi = Directives.UpdatePreconditioner()
self.inv = Inversion.BaseInversion(
invProb,
directiveList=[
ProjSpherical, IRLS, update_SensWeight, update_Jacobi
]
)
def setUp(self):
cs = 25.
hx = [(cs, 0, -1.3), (cs, 21), (cs, 0, 1.3)]
hy = [(cs, 0, -1.3), (cs, 21), (cs, 0, 1.3)]
hz = [(cs, 0, -1.3), (cs, 20), (cs, 0, 1.3)]
mesh = Mesh.TensorMesh([hx, hy, hz], x0="CCC")
blkind0 = Utils.ModelBuilder.getIndicesSphere(
np.r_[-100., -100., -200.], 75., mesh.gridCC
)
blkind1 = Utils.ModelBuilder.getIndicesSphere(
np.r_[100., 100., -200.], 75., mesh.gridCC
)
sigma = np.ones(mesh.nC)*1e-2
airind = mesh.gridCC[:, 2] > 0.
sigma[airind] = 1e-8
eta = np.zeros(mesh.nC)
tau = np.ones_like(sigma) * 1.
c = np.ones_like(sigma) * 0.5
eta[blkind0] = 0.1
eta[blkind1] = 0.1
tau[blkind0] = 0.1
tau[blkind1] = 0.01
actmapeta = Maps.InjectActiveCells(mesh, ~airind, 0.)
actmaptau = Maps.InjectActiveCells(mesh, ~airind, 1.)
actmapc = Maps.InjectActiveCells(mesh, ~airind, 1.)
x = mesh.vectorCCx[(mesh.vectorCCx > -155.) & (mesh.vectorCCx < 155.)]
y = mesh.vectorCCy[(mesh.vectorCCy > -155.) & (mesh.vectorCCy < 155.)]
Aloc = np.r_[-200., 0., 0.]
Bloc = np.r_[200., 0., 0.]
M = Utils.ndgrid(x-25., y, np.r_[0.])
N = Utils.ndgrid(x+25., y, np.r_[0.])
times = np.arange(10)*1e-3 + 1e-3
rx = SIP.Rx.Dipole(M, N, times)
src = SIP.Src.Dipole([rx], Aloc, Bloc)
survey = SIP.Survey([src])
wires = Maps.Wires(('eta', actmapeta.nP), ('taui', actmaptau.nP), ('c', actmapc.nP))
problem = SIP.Problem3D_N(
mesh,
sigma=sigma,
etaMap=actmapeta*wires.eta,
tauiMap=actmaptau*wires.taui,
cMap=actmapc*wires.c,
actinds=~airind,
storeJ = True,
verbose=False
)
problem.Solver = Solver
problem.pair(survey)
mSynth = np.r_[eta[~airind], 1./tau[~airind], c[~airind]]
survey.makeSyntheticData(mSynth)
# Now set up the problem to do some minimization
dmis = DataMisfit.l2_DataMisfit(survey)
dmis = DataMisfit.l2_DataMisfit(survey)
reg_eta = Regularization.Simple(mesh, mapping=wires.eta, indActive=~airind)
reg_taui = Regularization.Simple(mesh, mapping=wires.taui, indActive=~airind)
reg_c = Regularization.Simple(mesh, mapping=wires.c, indActive=~airind)
reg = reg_eta + reg_taui + reg_c
opt = Optimization.InexactGaussNewton(
maxIterLS=20, maxIter=10, tolF=1e-6,
tolX=1e-6, tolG=1e-6, maxIterCG=6
)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=1e4)
inv = Inversion.BaseInversion(invProb)
self.inv = inv
self.reg = reg
self.p = problem
self.mesh = mesh
self.m0 = mSynth
self.survey = survey
self.dmis = dmis
def run(plotIt=True):
# Define the inducing field parameter
H0 = (50000, 90, 0)
# Create a mesh
dx = 5.
hxind = [(dx, 5, -1.3), (dx, 10), (dx, 5, 1.3)]
hyind = [(dx, 5, -1.3), (dx, 10), (dx, 5, 1.3)]
hzind = [(dx, 5, -1.3), (dx, 10)]
mesh = Mesh.TensorMesh([hxind, hyind, hzind], 'CCC')
# Get index of the center
midx = int(mesh.nCx/2)
midy = int(mesh.nCy/2)
# Lets create a simple Gaussian topo and set the active cells
[xx, yy] = np.meshgrid(mesh.vectorNx, mesh.vectorNy)
zz = -np.exp((xx**2 + yy**2) / 75**2) + mesh.vectorNz[-1]
# We would usually load a topofile
topo = np.c_[Utils.mkvc(xx), Utils.mkvc(yy), Utils.mkvc(zz)]
# Go from topo to actv cells
actv = Utils.surface2ind_topo(mesh, topo, 'N')
actv = np.asarray([inds for inds, elem in enumerate(actv, 1) if elem],
dtype=int) - 1
# Create active map to go from reduce space to full
actvMap = Maps.InjectActiveCells(mesh, actv, -100)
nC = len(actv)
# Create and array of observation points
xr = np.linspace(-20., 20., 20)
yr = np.linspace(-20., 20., 20)
X, Y = np.meshgrid(xr, yr)
# Move the observation points 5m above the topo
Z = -np.exp((X**2 + Y**2) / 75**2) + mesh.vectorNz[-1] + 5.
# Create a MAGsurvey
rxLoc = np.c_[Utils.mkvc(X.T), Utils.mkvc(Y.T), Utils.mkvc(Z.T)]
rxLoc = PF.BaseMag.RxObs(rxLoc)
srcField = PF.BaseMag.SrcField([rxLoc], param=H0)
survey = PF.BaseMag.LinearSurvey(srcField)
# We can now create a susceptibility model and generate data
# Here a simple block in half-space
model = np.zeros((mesh.nCx, mesh.nCy, mesh.nCz))
model[(midx-2):(midx+2), (midy-2):(midy+2), -6:-2] = 0.02
model = Utils.mkvc(model)
model = model[actv]
# Create active map to go from reduce set to full
actvMap = Maps.InjectActiveCells(mesh, actv, -100)
# Creat reduced identity map
idenMap = Maps.IdentityMap(nP=nC)
# Create the forward model operator
prob = PF.Magnetics.MagneticIntegral(mesh, chiMap=idenMap, actInd=actv)
# Pair the survey and problem
survey.pair(prob)
# Compute linear forward operator and compute some data
d = prob.fields(model)
# Add noise and uncertainties
# We add some random Gaussian noise (1nT)
data = d + np.random.randn(len(d))
wd = np.ones(len(data))*1. # Assign flat uncertainties
survey.dobs = data
survey.std = wd
survey.mtrue = model
# Create sensitivity weights from our linear forward operator
rxLoc = survey.srcField.rxList[0].locs
wr = np.sum(prob.G**2., axis=0)**0.5
wr = (wr/np.max(wr))
# Create a regularization
reg = Regularization.Sparse(mesh, indActive=actv, mapping=idenMap)
reg.cell_weights = wr
reg.norms = [0, 1, 1, 1]
reg.eps_p, reg.eps_q = 1e-3, 1e-3
# Data misfit function
dmis = DataMisfit.l2_DataMisfit(survey)
dmis.W = 1/wd
# Add directives to the inversion
opt = Optimization.ProjectedGNCG(maxIter=100, lower=0., upper=1.,
maxIterLS=20, maxIterCG=10, tolCG=1e-3)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
betaest = Directives.BetaEstimate_ByEig()
# Here is where the norms are applied
# Use pick a treshold parameter empirically based on the distribution of
# model parameters
IRLS = Directives.Update_IRLS(f_min_change=1e-3, minGNiter=3)
update_Jacobi = Directives.Update_lin_PreCond()
inv = Inversion.BaseInversion(invProb,
directiveList=[IRLS, betaest, update_Jacobi])
# Run the inversion
m0 = np.ones(nC)*1e-4 # Starting model
mrec = inv.run(m0)
if plotIt:
# Here is the recovered susceptibility model
ypanel = midx
zpanel = -5
m_l2 = actvMap * IRLS.l2model
m_l2[m_l2 == -100] = np.nan
m_lp = actvMap * mrec
m_lp[m_lp == -100] = np.nan
m_true = actvMap * model
m_true[m_true == -100] = np.nan
# Plot the data
PF.Magnetics.plot_obs_2D(rxLoc, d=d)
plt.figure()
# Plot L2 model
ax = plt.subplot(321)
mesh.plotSlice(m_l2, ax=ax, normal='Z', ind=zpanel,
grid=True, clim=(model.min(), model.max()))
plt.plot(([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
([mesh.vectorCCy[ypanel], mesh.vectorCCy[ypanel]]), color='w')
plt.title('Plan l2-model.')
plt.gca().set_aspect('equal')
plt.ylabel('y')
ax.xaxis.set_visible(False)
plt.gca().set_aspect('equal', adjustable='box')
# Vertica section
ax = plt.subplot(322)
mesh.plotSlice(m_l2, ax=ax, normal='Y', ind=midx,
grid=True, clim=(model.min(), model.max()))
plt.plot(([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
([mesh.vectorCCz[zpanel], mesh.vectorCCz[zpanel]]), color='w')
plt.title('E-W l2-model.')
plt.gca().set_aspect('equal')
ax.xaxis.set_visible(False)
plt.ylabel('z')
plt.gca().set_aspect('equal', adjustable='box')
# Plot Lp model
ax = plt.subplot(323)
mesh.plotSlice(m_lp, ax=ax, normal='Z', ind=zpanel,
grid=True, clim=(model.min(), model.max()))
plt.plot(([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
([mesh.vectorCCy[ypanel], mesh.vectorCCy[ypanel]]), color='w')
plt.title('Plan lp-model.')
plt.gca().set_aspect('equal')
ax.xaxis.set_visible(False)
plt.ylabel('y')
plt.gca().set_aspect('equal', adjustable='box')
# Vertical section
ax = plt.subplot(324)
mesh.plotSlice(m_lp, ax=ax, normal='Y', ind=midx,
grid=True, clim=(model.min(), model.max()))
plt.plot(([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
([mesh.vectorCCz[zpanel], mesh.vectorCCz[zpanel]]), color='w')
plt.title('E-W lp-model.')
plt.gca().set_aspect('equal')
ax.xaxis.set_visible(False)
plt.ylabel('z')
plt.gca().set_aspect('equal', adjustable='box')
# Plot True model
ax = plt.subplot(325)
mesh.plotSlice(m_true, ax=ax, normal='Z', ind=zpanel,
grid=True, clim=(model.min(), model.max()))
plt.plot(([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
([mesh.vectorCCy[ypanel], mesh.vectorCCy[ypanel]]), color='w')
plt.title('Plan true model.')
plt.gca().set_aspect('equal')
plt.xlabel('x')
plt.ylabel('y')
plt.gca().set_aspect('equal', adjustable='box')
# Vertical section
ax = plt.subplot(326)
mesh.plotSlice(m_true, ax=ax, normal='Y', ind=midx,
grid=True, clim=(model.min(), model.max()))
plt.plot(([mesh.vectorCCx[0], mesh.vectorCCx[-1]]),
([mesh.vectorCCz[zpanel], mesh.vectorCCz[zpanel]]), color='w')
plt.title('E-W true model.')
plt.gca().set_aspect('equal')
plt.xlabel('x')
plt.ylabel('z')
plt.gca().set_aspect('equal', adjustable='box')
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
reg_p.mref = np.zeros(3 * nC)
reg_p.cell_weights = (wires.p * wr)
reg_s = Regularization.Sparse(mesh, indActive=actv, mapping=wires.s)
reg_s.mref = np.zeros(3 * nC)
reg_s.cell_weights = (wires.s * wr)
reg_t = Regularization.Sparse(mesh, indActive=actv, mapping=wires.t)
reg_t.mref = np.zeros(3 * nC)
reg_t.cell_weights = (wires.t * wr)
reg = reg_p + reg_s + reg_t
reg.mref = np.zeros(3 * nC)
# Data misfit function
dmis = DataMisfit.l2_DataMisfit(survey)
dmis.W = 1. / survey.std
# Add directives to the inversion
opt = Optimization.ProjectedGNCG(maxIter=30,
lower=-10,
upper=10.,
maxIterLS=20,
maxIterCG=20,
tolCG=1e-4)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
# A list of directive to control the inverson
betaest = Directives.BetaEstimate_ByEig()
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=False):
O = np.r_[-1.2, -1.]
D = np.r_[10., 10.]
x = np.r_[0., 1.]
y = np.r_[0., 1.]
print('length:', StraightRay.lengthInCell(O, D, x, y, plotIt=plotIt))
O = np.r_[0, -1.]
D = np.r_[1., 1.]*1.5
print('length:', StraightRay.lengthInCell(O, D, x*2, y*2, plotIt=plotIt))
nC = 20
M = Mesh.TensorMesh([nC, nC])
y = np.linspace(0., 1., nC/2)
rlocs = np.c_[y*0+M.vectorCCx[-1], y]
rx = StraightRay.Rx(rlocs, None)
srcList = [
StraightRay.Src(loc=np.r_[M.vectorCCx[0], yi], rxList=[rx])
for yi in y
]
survey = StraightRay.Survey(srcList)
problem = StraightRay.Problem(M, slownessMap=Maps.IdentityMap(M))
problem.pair(survey)
s = Utils.mkvc(Utils.ModelBuilder.randomModel(M.vnC)) + 1.
survey.dobs = survey.dpred(s)
survey.std = 0.01
# Create an optimization program
reg = Regularization.Tikhonov(M)
dmis = DataMisfit.l2_DataMisfit(survey)
opt = Optimization.InexactGaussNewton(maxIter=40)
opt.remember('xc')
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
beta = Directives.BetaSchedule()
betaest = Directives.BetaEstimate_ByEig()
inv = Inversion.BaseInversion(invProb, directiveList=[beta, betaest])
# Start the inversion with a model of zeros, and run the inversion
m0 = np.ones(M.nC)*1.5
mopt = inv.run(m0)
if plotIt is True:
fig, ax = plt.subplots(1, 2, figsize=(8, 4))
ax[1].plot(survey.dobs)
ax[1].plot(survey.dpred(m0), 's')
ax[1].plot(survey.dpred(mopt), 'o')
ax[1].legend(['dobs', 'starting dpred', 'dpred'])
M.plotImage(s, ax=ax[0])
survey.plot(ax=ax[0])
ax[0].set_title('survey')
plt.tight_layout()
if plotIt is True:
fig, ax = plt.subplots(1, 3, figsize=(12, 4))
plt.colorbar(M.plotImage(m0, ax=ax[0])[0], ax=ax[0])
plt.colorbar(M.plotImage(mopt, ax=ax[1])[0], ax=ax[1])
plt.colorbar(M.plotImage(s, ax=ax[2])[0], ax=ax[2])
ax[0].set_title('Starting Model')
ax[1].set_title('Recovered Model')
ax[2].set_title('True Model')
plt.tight_layout()
