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 fit_colecole_with_se(self, eta_cc=0.8, tau_cc=0.003, c_cc=0.6):
def ColeColeSeigel(f, sigmaInf, eta, tau, c):
w = 2 * np.pi * f
return sigmaInf * (1 - eta / (1 + (1j * w * tau)**c))
# Step1: Fit Cole-Cole with Stretched Exponential function
time = np.logspace(-6, np.log10(0.01), 41)
wt, tbase, omega_int = DigFilter.setFrequency(time)
frequency = omega_int / (2 * np.pi)
# Cole-Cole parameters
siginf = 1.
self.eta_cc = eta_cc
self.tau_cc = tau_cc
self.c_cc = c_cc
sigma = ColeColeSeigel(frequency, siginf, eta_cc, tau_cc, c_cc)
sigTCole = DigFilter.transFiltImpulse(sigma,
wt,
tbase,
omega_int,
time,
tol=1e-12)
wires = Maps.Wires(('eta', 1), ('tau', 1), ('c', 1))
taumap = Maps.ExpMap(nP=1) * wires.tau
survey = SESurvey()
dtrue = -sigTCole
survey.dobs = dtrue
m1D = Mesh.TensorMesh([np.ones(3)])
prob = SEInvImpulseProblem(m1D,
etaMap=wires.eta,
tauMap=taumap,
cMap=wires.c)
update_sens = Directives.UpdateSensitivityWeights()
prob.time = time
prob.pair(survey)
m0 = np.r_[eta_cc, np.log(tau_cc), c_cc]
perc = 0.05
dmisfitpeta = DataMisfit.l2_DataMisfit(survey)
dmisfitpeta.W = 1 / (abs(survey.dobs) * perc)
reg = regularization.Simple(m1D)
opt = Optimization.ProjectedGNCG(maxIter=10)
invProb = InvProblem.BaseInvProblem(dmisfitpeta, reg, opt)
# Create an inversion object
target = Directives.TargetMisfit()
invProb.beta = 0.
inv = Inversion.BaseInversion(invProb, directiveList=[target])
reg.mref = 0. * m0
prob.counter = opt.counter = Utils.Counter()
opt.LSshorten = 0.5
opt.remember('xc')
opt.tolX = 1e-20
opt.tolF = 1e-20
opt.tolG = 1e-20
opt.eps = 1e-20
mopt = inv.run(m0)
return mopt
def solve(self):
# Tikhonov Inversion
####################
# Initial model values
m0 = np.median(self.ln_sigback) * np.ones(self.mapping.nP)
m0 += np.random.randn(m0.size)
# Misfit functional
dmis = DataMisfit.l2_DataMisfit(self.survey.simpeg_survey)
# Regularization functional
regT = Regularization.Simple(self.mesh,
alpha_s=10.0,
alpha_x=10.0,
alpha_y=10.0,
alpha_z=10.0,
indActive=self.actind)
# Personal preference for this solver with a Jacobi preconditioner
opt = Optimization.ProjectedGNCG(maxIter=8, tolX=1, maxIterCG=30)
#opt = Optimization.ProjectedGradient(maxIter=100, tolX=1e-2,
# maxIterLS=20, maxIterCG=30, tolCG=1e-4)
opt.printers.append(Optimization.IterationPrinters.iterationLS)
#print(opt.printersLS)
# Optimization class keeps value of 'xc'. Seems to be solution for the model parameters
opt.remember('xc')
invProb = InvProblem.BaseInvProblem(dmis, regT, opt)
# Options for the inversion algorithm in particular selection of Beta weight for regularization.
# How to choose initial estimate for beta
beta = Directives.BetaEstimate_ByEig(beta0_ratio=1.)
Target = Directives.TargetMisfit()
# Beta changing algorithm.
betaSched = Directives.BetaSchedule(coolingFactor=5., coolingRate=2)
# Change model weights, seems sensitivity of conductivity ?? Not sure.
updateSensW = Directives.UpdateSensitivityWeights(threshold=1e-3)
# Use Jacobi preconditioner ( the only available).
update_Jacobi = Directives.UpdatePreconditioner()
inv = Inversion.BaseInversion(invProb,
directiveList=[
beta, Target, betaSched, updateSensW,
update_Jacobi
])
self.minv = inv.run(m0)
def 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
alpha_y=alphas[10],
alpha_z=alphas[11])
reg_t.alphas = alphas[8:]
reg_t.cell_weights = (wires.t * global_weights)
reg_t.norms = np.c_[2, 2, 2, 2]
reg_t.mref = mref
# Assemble the 3-component regularizations
reg = reg_p + reg_s + reg_t
reg.mref = mref
# 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=30,
tolCG=1e-3)
# Create the default L2 inverse problem from the above objects
invProb = InvProblem.BaseInvProblem(global_misfit, reg, opt)
# Specify how the initial beta is found
# if input_dict["inversion_type"].lower() in ['mvi', 'mvis']:
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1e+1)
# Pre-conditioner
update_Jacobi = Directives.UpdatePreconditioner()
IRLS = Directives.Update_IRLS(f_min_change=1e-3,
minGNiter=1,
def setUp(self):
ndv = -100
# 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
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((mesh.nCx, mesh.nCy, 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(mesh, actv, ndv)
# 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(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(mesh, locXYZ, actv, 2., 2.)
wr = wr**2.
# 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 = 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-3,
minGNiter=3)
update_Jacobi = Directives.Update_lin_PreCond(mapping=idenMap)
self.inv = Inversion.BaseInversion(invProb,
directiveList=[IRLS,
update_Jacobi])
def run(plotIt=True):
nC = 40
de = 1.
h = np.ones(nC) * de / nC
M = Mesh.TensorMesh([h, h])
y = np.linspace(M.vectorCCy[0], M.vectorCCx[-1], int(np.floor(nC / 4)))
rlocs = np.c_[0 * y + 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
]
# phi model
phi0 = 0
phi1 = 0.65
phitrue = Utils.ModelBuilder.defineBlock(M.gridCC, [0.4, 0.6], [0.6, 0.4],
[phi1, phi0])
knownVolume = np.sum(phitrue * M.vol)
print('True Volume: {}'.format(knownVolume))
# Set up true conductivity model and plot the model transform
sigma0 = np.exp(1)
sigma1 = 1e4
if plotIt:
fig, ax = plt.subplots(1, 1)
sigmaMapTest = Maps.SelfConsistentEffectiveMedium(nP=1000,
sigma0=sigma0,
sigma1=sigma1,
rel_tol=1e-1,
maxIter=150)
testphis = np.linspace(0., 1., 1000)
sigetest = sigmaMapTest * testphis
ax.semilogy(testphis, sigetest)
ax.set_title('Model Transform')
ax.set_xlabel('$\\varphi$')
ax.set_ylabel('$\sigma$')
sigmaMap = Maps.SelfConsistentEffectiveMedium(M,
sigma0=sigma0,
sigma1=sigma1)
# scale the slowness so it is on a ~linear scale
slownessMap = Maps.LogMap(M) * sigmaMap
# set up the true sig model and log model dobs
sigtrue = sigmaMap * phitrue
# modt = Model.BaseModel(M);
slownesstrue = slownessMap * phitrue # true model (m = log(sigma))
# set up the problem and survey
survey = StraightRay.Survey(srcList)
problem = StraightRay.Problem(M, slownessMap=slownessMap)
problem.pair(survey)
if plotIt:
fig, ax = plt.subplots(1, 1)
cb = plt.colorbar(M.plotImage(phitrue, ax=ax)[0], ax=ax)
survey.plot(ax=ax)
cb.set_label('$\\varphi$')
# get observed data
dobs = survey.makeSyntheticData(phitrue, std=0.03, force=True)
dpred = survey.dpred(np.zeros(M.nC))
# objective function pieces
reg = Regularization.Tikhonov(M)
dmis = DataMisfit.l2_DataMisfit(survey)
dmisVol = Volume(mesh=M, knownVolume=knownVolume)
beta = 0.25
maxIter = 15
# without the volume regularization
opt = Optimization.ProjectedGNCG(maxIter=maxIter, lower=0.0, upper=1.0)
opt.remember('xc')
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=beta)
inv = Inversion.BaseInversion(invProb)
mopt1 = inv.run(np.zeros(M.nC) + 1e-16)
print('\nTotal recovered volume (no vol misfit term in inversion): '
'{}'.format(dmisVol(mopt1)))
# with the volume regularization
vol_multiplier = 9e4
reg2 = reg
dmis2 = dmis + vol_multiplier * dmisVol
opt2 = Optimization.ProjectedGNCG(maxIter=maxIter, lower=0.0, upper=1.0)
opt2.remember('xc')
invProb2 = InvProblem.BaseInvProblem(dmis2, reg2, opt2, beta=beta)
inv2 = Inversion.BaseInversion(invProb2)
mopt2 = inv2.run(np.zeros(M.nC) + 1e-16)
print('\nTotal volume (vol misfit term in inversion): {}'.format(
dmisVol(mopt2)))
# plot results
if plotIt:
fig, ax = plt.subplots(1, 1)
ax.plot(dobs)
ax.plot(dpred)
ax.plot(survey.dpred(mopt1), 'o')
ax.plot(survey.dpred(mopt2), 's')
ax.legend(['dobs', 'dpred0', 'dpred w/o Vol', 'dpred with Vol'])
fig, ax = plt.subplots(1, 3, figsize=(16, 4))
cb0 = plt.colorbar(M.plotImage(phitrue, ax=ax[0])[0], ax=ax[0])
cb1 = plt.colorbar(M.plotImage(mopt1, ax=ax[1])[0], ax=ax[1])
cb2 = plt.colorbar(M.plotImage(mopt2, ax=ax[2])[0], ax=ax[2])
for cb in [cb0, cb1, cb2]:
cb.set_clim([0., phi1])
ax[0].set_title('true, vol: {:1.3e}'.format(knownVolume))
ax[1].set_title('recovered(no Volume term), vol: {:1.3e} '.format(
dmisVol(mopt1)))
ax[2].set_title('recovered(with Volume term), vol: {:1.3e} '.format(
dmisVol(mopt2)))
plt.tight_layout()
idenMap = Maps.IdentityMap(nP=nC)
# Create static map
prob = PF.Magnetics.MagneticIntegral(mesh, chiMap=idenMap, actInd=surf, equiSourceLayer=True)
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)
def run_inversion(
m0, survey, actind, mesh,
std, eps,
maxIter=15, beta0_ratio=1e0,
coolingFactor=5, coolingRate=2,
upper=np.inf, lower=-np.inf,
use_sensitivity_weight=False,
alpha_s=1e-4,
alpha_x=1.,
alpha_y=1.,
alpha_z=1.,
):
"""
Run IP inversion
"""
dmisfit = DataMisfit.l2_DataMisfit(survey)
uncert = abs(survey.dobs) * std + eps
dmisfit.W = 1./uncert
# Map for a regularization
regmap = Maps.IdentityMap(nP=int(actind.sum()))
# Related to inversion
if use_sensitivity_weight:
reg = Regularization.Sparse(
mesh, indActive=actind, mapping=regmap
)
reg.alpha_s = alpha_s
reg.alpha_x = alpha_x
reg.alpha_y = alpha_y
reg.alpha_z = alpha_z
else:
reg = Regularization.Sparse(
mesh, indActive=actind, mapping=regmap,
cell_weights=mesh.vol[actind]
)
reg.alpha_s = alpha_s
reg.alpha_x = alpha_x
reg.alpha_y = alpha_y
reg.alpha_z = alpha_z
opt = Optimization.ProjectedGNCG(maxIter=maxIter, upper=upper, lower=lower)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
beta = Directives.BetaSchedule(
coolingFactor=coolingFactor, coolingRate=coolingRate
)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=beta0_ratio)
target = Directives.TargetMisfit()
# Need to have basice saving function
if use_sensitivity_weight:
updateSensW = Directives.UpdateSensitivityWeights()
update_Jacobi = Directives.UpdatePreconditioner()
directiveList = [
beta, betaest, target, update_Jacobi
]
else:
directiveList = [
beta, betaest, target
]
inv = Inversion.BaseInversion(
invProb, directiveList=directiveList
)
opt.LSshorten = 0.5
opt.remember('xc')
# Run inversion
mopt = inv.run(m0)
return mopt, invProb.dpred
problem.Solver = Solver
survey.dpred(mtrue[actind])
survey.makeSyntheticData(mtrue[actind], std=0.05, force=True)
# Tikhonov Inversion
####################
m0 = np.median(ln_sigback) * np.ones(mapping.nP)
dmis = DataMisfit.l2_DataMisfit(survey)
regT = Regularization.Simple(mesh, indActive=actind)
# Personal preference for this solver with a Jacobi preconditioner
opt = Optimization.ProjectedGNCG(maxIter=20,
lower=-10,
upper=10,
maxIterLS=20,
maxIterCG=30,
tolCG=1e-4)
opt.remember('xc')
invProb = InvProblem.BaseInvProblem(dmis, regT, opt)
beta = Directives.BetaEstimate_ByEig(beta0_ratio=1.)
Target = Directives.TargetMisfit()
betaSched = Directives.BetaSchedule(coolingFactor=5., coolingRate=2)
updateSensW = Directives.UpdateSensitivityWeights(threshold=1e-3)
update_Jacobi = Directives.UpdatePreconditioner()
inv = Inversion.BaseInversion(
invProb,
directiveList=[beta, Target, betaSched, updateSensW, update_Jacobi])
alpha_y=alphas[10],
alpha_z=alphas[11]
)
reg_t.cell_weights = (regularization_map.t * global_weights)
reg_t.norms = np.c_[model_norms].T
reg_t.mref = mref
# Assemble the 3-component regularizations
reg = reg_p + reg_s + reg_t
# Specify how the optimization will proceed, set susceptibility bounds to inf
opt = Optimization.ProjectedGNCG(
maxIter=max_global_iterations,
lower=lower_bound, upper=upper_bound,
maxIterLS=20, maxIterCG=30, tolCG=1e-3,
stepOffBoundsFact=1e-8,
LSshorten=0.25
)
# Create the default L2 inverse problem from the above objects
invProb = InvProblem.BaseInvProblem(global_misfit, reg, opt, beta=initial_beta)
# Add a list of directives to the inversion
directiveList = []
if vector_property:
# chifact_target (MVIS-only) should be higher than target_chi.
# If MVIS has problems, try increasing chifact_target.
directiveList.append(Directives.VectorInversion(
inversion_type=input_dict["inversion_type"],
def setUp(self):
# We will assume a vertical inducing field
H0 = (50000., 90., 0.)
# The magnetization is set along a different direction (induced + remanence)
M = np.array([90., 0.])
# Block with an effective susceptibility
chi_e = 0.05
# 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.))
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
rxLoc = np.c_[Utils.mkvc(X.T), Utils.mkvc(Y.T), Utils.mkvc(Z.T)]
Rx = PF.BaseMag.RxObs(rxLoc)
srcField = PF.BaseMag.SrcField([Rx], param=H0)
survey = PF.BaseMag.LinearSurvey(srcField)
# Create a mesh
h = [5, 5, 5]
padDist = np.ones((3, 2)) * 100
nCpad = [4, 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
# For now equal in 3D
nCx, nCy, nCz = 2**(maxLevel), 2**(maxLevel), 2**(maxLevel)
# Define the mesh and origin
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()
# Define an active cells from topo
actv = Utils.surface2ind_topo(mesh, topo)
nC = int(actv.sum())
# Convert the inclination declination to vector in Cartesian
M_xyz = Utils.matutils.dip_azimuth2cartesian(
np.ones(nC) * M[0],
np.ones(nC) * 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 value, inducing field strength will
# be applied in by the :class:`SimPEG.PF.Magnetics` problem
model = np.zeros(mesh.nC)
model[ind] = chi_e
# Remove air cells
self.model = model[actv]
# Create active map to go from reduce set to full
self.actvPlot = Maps.InjectActiveCells(mesh, actv, np.nan)
# Creat reduced identity map
idenMap = Maps.IdentityMap(nP=nC)
# Create the forward model operator
prob = PF.Magnetics.MagneticIntegral(mesh,
M=M_xyz,
chiMap=idenMap,
actInd=actv)
# Pair the survey and problem
survey.pair(prob)
# Compute some data and add some random noise
data = prob.fields(self.model)
# Split the data in components
nD = rxLoc.shape[0]
std = 5 # nT
data += np.random.randn(nD) * std
wd = np.ones(nD) * std
# Assigne data and uncertainties to the survey
survey.dobs = data
survey.std = wd
######################################################################
# Equivalent Source
# Get the active cells for equivalent source is the top only
surf = Utils.modelutils.surface_layer_index(mesh, topo)
# Get the layer of cells directyl below topo
nC = np.count_nonzero(surf) # Number of active cells
# Create active map to go from reduce set to full
surfMap = Maps.InjectActiveCells(mesh, surf, np.nan)
# Create identity map
idenMap = Maps.IdentityMap(nP=nC)
# Create static map
prob = PF.Magnetics.MagneticIntegral(mesh,
chiMap=idenMap,
actInd=surf,
parallelized=False,
equiSourceLayer=True)
prob.solverOpts['accuracyTol'] = 1e-4
# Pair the survey and problem
if survey.ispaired:
survey.unpair()
survey.pair(prob)
# Create a regularization function, in this case l2l2
reg = Regularization.Sparse(mesh,
indActive=surf,
mapping=Maps.IdentityMap(nP=nC),
scaledIRLS=False)
reg.mref = np.zeros(nC)
# Specify how the optimization will proceed,
# set susceptibility bounds to inf
opt = Optimization.ProjectedGNCG(maxIter=20,
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()
# Target misfit to stop the inversion,
# try to fit as much as possible of the signal,
# we don't want to lose anything
IRLS = Directives.Update_IRLS(f_min_change=1e-3,
minGNiter=1,
beta_tol=1e-1)
update_Jacobi = Directives.UpdatePreconditioner()
# Put all the parts together
inv = Inversion.BaseInversion(
invProb, directiveList=[betaest, IRLS, update_Jacobi])
# Run the equivalent source inversion
mstart = np.ones(nC) * 1e-4
mrec = inv.run(mstart)
# Won't store the sensitivity and output 'xyz' data.
prob.forwardOnly = True
prob.rx_type = 'xyz'
prob._G = None
prob.modelType = 'amplitude'
prob.model = mrec
pred = prob.fields(mrec)
bx = pred[:nD]
by = pred[nD:2 * nD]
bz = pred[2 * nD:]
bAmp = (bx**2. + by**2. + bz**2.)**0.5
# AMPLITUDE INVERSION
# Create active map to go from reduce space to full
actvMap = Maps.InjectActiveCells(mesh, actv, -100)
nC = int(actv.sum())
# Create identity map
idenMap = Maps.IdentityMap(nP=nC)
self.mstart = np.ones(nC) * 1e-4
# Create the forward model operator
prob = PF.Magnetics.MagneticIntegral(mesh,
chiMap=idenMap,
actInd=actv,
modelType='amplitude',
rx_type='xyz')
prob.model = self.mstart
# Change the survey to xyz components
surveyAmp = PF.BaseMag.LinearSurvey(survey.srcField)
# Pair the survey and problem
surveyAmp.pair(prob)
# Create a regularization function, in this case l2l2
wr = np.sum(prob.G**2., axis=0)**0.5
wr = (wr / np.max(wr))
# Re-set the observations to |B|
surveyAmp.dobs = bAmp
surveyAmp.std = wd
# Create a sparse regularization
reg = Regularization.Sparse(mesh, indActive=actv, mapping=idenMap)
reg.norms = np.c_[0, 0, 0, 0]
reg.mref = np.zeros(nC)
reg.cell_weights = wr
# Data misfit function
dmis = DataMisfit.l2_DataMisfit(surveyAmp)
dmis.W = 1. / surveyAmp.std
# Add directives to the inversion
opt = Optimization.ProjectedGNCG(maxIter=30,
lower=0.,
upper=1.,
maxIterLS=20,
maxIterCG=20,
tolCG=1e-3)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
# Here is the list of directives
betaest = Directives.BetaEstimate_ByEig()
# Specify the sparse norms
IRLS = Directives.Update_IRLS(f_min_change=1e-3,
minGNiter=1,
coolingRate=1,
betaSearch=False)
# The sensitivity weights are update between each iteration.
update_SensWeight = Directives.UpdateSensitivityWeights()
update_Jacobi = Directives.UpdatePreconditioner(threshold=1 - 3)
# Put all together
self.inv = Inversion.BaseInversion(
invProb,
directiveList=[betaest, IRLS, update_SensWeight, update_Jacobi])
self.mesh = mesh
def run_inversion(
m0,
survey,
actind,
mesh,
wires,
std,
eps,
maxIter=15,
beta0_ratio=1e0,
coolingFactor=2,
coolingRate=2,
maxIterLS=20,
maxIterCG=10,
LSshorten=0.5,
eta_lower=1e-5,
eta_upper=1,
tau_lower=1e-6,
tau_upper=10.,
c_lower=1e-2,
c_upper=1.,
is_log_tau=True,
is_log_c=True,
is_log_eta=True,
mref=None,
alpha_s=1e-4,
alpha_x=1e0,
alpha_y=1e0,
alpha_z=1e0,
):
"""
Run Spectral Spectral IP inversion
"""
dmisfit = DataMisfit.l2_DataMisfit(survey)
uncert = abs(survey.dobs) * std + eps
dmisfit.W = 1. / uncert
# Map for a regularization
# Related to inversion
# Set Upper and Lower bounds
e = np.ones(actind.sum())
if np.isscalar(eta_lower):
eta_lower = e * eta_lower
if np.isscalar(tau_lower):
tau_lower = e * tau_lower
if np.isscalar(c_lower):
c_lower = e * c_lower
if np.isscalar(eta_upper):
eta_upper = e * eta_upper
if np.isscalar(tau_upper):
tau_upper = e * tau_upper
if np.isscalar(c_upper):
c_upper = e * c_upper
if is_log_eta:
eta_upper = np.log(eta_upper)
eta_lower = np.log(eta_lower)
if is_log_tau:
tau_upper = np.log(tau_upper)
tau_lower = np.log(tau_lower)
if is_log_c:
c_upper = np.log(c_upper)
c_lower = np.log(c_lower)
m_upper = np.r_[eta_upper, tau_upper, c_upper]
m_lower = np.r_[eta_lower, tau_lower, c_lower]
# Set up regularization
reg_eta = Regularization.Tikhonov(mesh,
mapping=wires.eta,
indActive=actind)
reg_tau = Regularization.Tikhonov(mesh,
mapping=wires.tau,
indActive=actind)
reg_c = Regularization.Tikhonov(mesh, mapping=wires.c, indActive=actind)
# Todo:
reg_eta.alpha_s = alpha_s
reg_tau.alpha_s = alpha_s
reg_c.alpha_s = alpha_s
reg_eta.alpha_x = alpha_x
reg_tau.alpha_x = alpha_x
reg_c.alpha_x = alpha_x
reg_eta.alpha_y = alpha_y
reg_tau.alpha_y = alpha_y
reg_c.alpha_y = alpha_y
reg_eta.alpha_z = alpha_z
reg_tau.alpha_z = alpha_z
reg_c.alpha_z = alpha_z
reg = reg_eta + reg_tau + reg_c
# Use Projected Gauss Newton scheme
opt = Optimization.ProjectedGNCG(maxIter=maxIter,
upper=m_upper,
lower=m_lower,
maxIterLS=maxIterLS,
maxIterCG=maxIterCG,
LSshorten=LSshorten)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
beta = Directives.BetaSchedule(coolingFactor=coolingFactor,
coolingRate=coolingRate)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=beta0_ratio)
target = Directives.TargetMisfit()
directiveList = [beta, betaest, target]
inv = Inversion.BaseInversion(invProb, directiveList=directiveList)
opt.LSshorten = 0.5
opt.remember('xc')
# Run inversion
mopt = inv.run(m0)
return mopt, invProb.dpred
def run_inversion(
self,
maxIter=60,
m0=0.0,
mref=0.0,
percentage=5,
floor=0.1,
chifact=1,
beta0_ratio=1.0,
coolingFactor=1,
n_iter_per_beta=1,
alpha_s=1.0,
alpha_x=1.0,
alpha_z=1.0,
use_target=False,
use_tikhonov=True,
use_irls=False,
p_s=2,
p_x=2,
p_y=2,
p_z=2,
beta_start=None,
):
self.uncertainty = percentage * abs(self.survey.dobs) * 0.01 + floor
m0 = np.ones(self.mesh.nC) * m0
mref = np.ones(self.mesh.nC) * mref
if ~use_tikhonov:
reg = Regularization.Sparse(
self.mesh,
alpha_s=alpha_s,
alpha_x=alpha_x,
alpha_y=alpha_z,
mref=mref,
mapping=Maps.IdentityMap(self.mesh),
cell_weights=self.mesh.vol,
)
else:
reg = Regularization.Tikhonov(
self.mesh,
alpha_s=alpha_s,
alpha_x=alpha_x,
alpha_y=alpha_z,
mref=mref,
mapping=Maps.IdentityMap(self.mesh),
)
dmis = DataMisfit.l2_DataMisfit(self.survey)
dmis.W = 1.0 / self.uncertainty
opt = Optimization.ProjectedGNCG(maxIter=maxIter, maxIterCG=20)
opt.lower = 0.0
opt.remember("xc")
opt.tolG = 1e-10
opt.eps = 1e-10
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
save = Directives.SaveOutputEveryIteration()
beta_schedule = Directives.BetaSchedule(coolingFactor=coolingFactor,
coolingRate=n_iter_per_beta)
if use_irls:
IRLS = Directives.Update_IRLS(
f_min_change=1e-4,
minGNiter=1,
silent=False,
maxIRLSiter=40,
beta_tol=5e-1,
coolEpsFact=1.3,
chifact_start=chifact,
)
if beta_start is None:
directives = [
Directives.BetaEstimate_ByEig(beta0_ratio=beta0_ratio),
IRLS,
save,
]
else:
directives = [IRLS, save]
invProb.beta = beta_start
reg.norms = np.c_[p_s, p_x, p_z, 2]
else:
target = Directives.TargetMisfit(chifact=chifact)
directives = [
Directives.BetaEstimate_ByEig(beta0_ratio=beta0_ratio),
beta_schedule,
save,
]
if use_target:
directives.append(target)
inv = Inversion.BaseInversion(invProb, directiveList=directives)
mopt = inv.run(m0)
model = opt.recall("xc")
model.append(mopt)
pred = []
for m in model:
pred.append(self.survey.dpred(m))
return model, pred, save
def fitWithStretchedExponetial(time, survey_ip, sources, Rho, start_time=None):
if start_time is None:
start_time = 0
# Choose all time channels
tinds = time > start_time
nLoc = survey_ip.dobs.T[tinds, :].shape[1]
# Setup wire for different properties
wires = Maps.Wires(('eta', nLoc), ('tau', nLoc), ('c', nLoc))
taumap = Maps.ExpMap(nP=nLoc) * wires.tau
etamap = Maps.ExpMap(nP=nLoc) * wires.eta
cmap = Maps.ExpMap(nP=nLoc) * wires.c
# This is almost dummmy mesh and xyz loc at the moment
# But, there is potential use later
m1D = Mesh.TensorMesh([np.ones(nLoc)])
# # Set survey
survey = SEMultiSurvey(time[tinds] * 1e-3, sources[:, :], n_pulse=2, T=4)
survey.dobs = (survey_ip.dobs.T[tinds, :]).flatten(order='F')
# Set problem
prob = SEMultiInvProblem(m1D, etaMap=etamap, tauMap=taumap, cMap=cmap)
prob.pair(survey)
# Set initial model
eta0, tau0, c0 = abs(
survey_ip.dobs.T[0, :].T), 1. * np.ones(nLoc), 1. * np.ones(nLoc)
m0 = np.r_[np.log(eta0), np.log(tau0), np.log(c0)]
std = 0.02
plt.plot(survey.dpred(m0))
plt.plot(survey.dobs, '.')
plt.title("Obs & pred")
plt.xlabel("data point")
plt.ylabel("value")
plt.show()
mreg = Mesh.TensorMesh([len(m0)])
dmisfit = DataMisfit.l2_DataMisfit(survey)
uncert = (abs(survey.dobs) * std + 0.01) * 1.1
dmisfit.W = 1. / uncert
reg = Regularization.Simple(mreg)
opt = Optimization.ProjectedGNCG(maxIter=20)
invProb = InvProblem.BaseInvProblem(dmisfit, reg, opt)
# Create an inversion object
target = Directives.TargetMisfit()
invProb.beta = 0.
inv = Inversion.BaseInversion(invProb, directiveList=[target])
# reg.mref = 0.*m0
prob.counter = opt.counter = Utils.Counter()
opt.LSshorten = 0.5
opt.remember('xc')
opt.tolX = 1e-20
opt.tolF = 1e-20
opt.tolG = 1e-20
opt.eps = 1e-20
m_upper = np.r_[np.ones_like(tau0) * np.log(200),
np.ones_like(tau0) * np.log(10.),
np.ones_like(tau0) * np.log(1.)]
m_lower = np.r_[np.ones_like(tau0) * np.log(1),
np.ones_like(tau0) * np.log(1e-2),
np.ones_like(tau0) * np.log(0.1)]
opt.lower = m_lower
opt.upper = m_upper
mopt = inv.run(m0)
eta = etamap * mopt
tau = taumap * mopt
c = cmap * mopt
DPRED = invProb.dpred.reshape((nLoc, time[tinds].size))
DOBS = survey.dobs.reshape((nLoc, time[tinds].size))
UNCERT = uncert.reshape((nLoc, time[tinds].size))
error = ((eta * 1e-3) /
np.sqrt(np.sum((DOBS - DPRED)**2, axis=1) / time[tinds].size))
from matplotlib import colors
fig = plt.figure(figsize=(6, 5))
active_inds = (Rho[:, 0] > 10.) & (Rho[:, 0] < 1e3) & (abs(
(DPRED - DOBS) / UNCERT).sum(axis=1) / time[tinds].size < 1.)
out = plt.scatter(tau[active_inds],
c[active_inds],
c=eta[active_inds],
norm=colors.LogNorm(),
cmap="magma",
s=2)
cb = plt.colorbar(out)
plt.xscale('log')
plt.yscale('log')
plt.xlabel("Tau")
plt.ylabel("c")
cb.set_label("Eta (mV/V)")
plt.show()
inds = (abs((DPRED - DOBS) / UNCERT).sum(axis=1) / time[tinds].size < 20.)
# print(inds)
inds = np.arange(survey.n_location)[inds]
out = plt.loglog(time[tinds], DPRED[inds[::2], :].T, 'r')
out = plt.loglog(time[tinds], DOBS[inds[::2], :].T, 'kx')
print(np.sum((DPRED - DOBS)**2) / time.size)
fig, axs = plt.subplots(4, 1)
properties = [
Rho[:, 0][active_inds], eta[active_inds], tau[active_inds],
c[active_inds]
]
titles = ["$\\rho_{a}$", "$\\eta_{a}$", "$\\tau_{a}$", "$c_{a}$"]
colors = ['#1f77b4', 'seagreen', 'crimson', 'gold']
for i, ax in enumerate(axs):
out = ax.hist(np.log10(properties[i]), bins=50, color=colors[i])
ax.set_title(titles[i])
ax.set_xticklabels([("%.1f") % (10**tick) for tick in ax.get_xticks()])
plt.tight_layout()
plt.show()
return eta, tau, c, error
def 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 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(-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 MAGsurvey
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 susceptibility 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] = 0.5
model[(midx+1):(midx+5), (midy-2):(midy+2), -10:-6] = -0.5
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 = [0, 1, 1, 1]
# 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()
# 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-2, minGNiter=2)
update_Jacobi = Directives.UpdatePreconditioner()
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 = -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
PF.Gravity.plot_obs_2D(rxLoc, d=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')
# Vertica 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')
wr = np.sum(prob.F**2., axis=0)**0.5
wr /= np.max(wr)
# Create a regularization
# Create a regularization
reg = Regularization.Sparse(mesh, indActive=actv, mapping=idenMap)
reg.norms = [0, 0, 0, 0]
reg.cell_weights = wr
reg.mref = np.zeros(nC)
# Add directives to the inversion
opt = Optimization.ProjectedGNCG(maxIter=20,
lower=[0.],
upper=[10.],
maxIterLS=10,
maxIterCG=20,
tolCG=1e-3,
stepOffBoundsFact=1e-8)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
# LIST OF DIRECTIVES
# betaest = Directives.BetaEstimate_ByEig()
IRLS = Directives.Update_IRLS(f_min_change=1e-4,
minGNiter=1,
beta_tol=1e-2,
coolingRate=1)
update_Jacobi = Directives.UpdatePreCond()
betaest = Directives.BetaEstimate_ByEig()
#saveModel = Directives.SaveUBCVectorsEveryIteration(mapping=actvMap,
Mesh.TreeMesh.writeUBC(mesh,
workDir + dsep + outDir + 'OctreeMeshGlobal.msh',
models={
workDir + dsep + outDir + 'SensWeights.mod':
activeCellsMap * wrGlobal
})
# Create a regularization function, in this case l2l2
reg = Regularization.Sparse(mesh, indActive=activeCells, mapping=idenMap)
reg.mref = np.zeros(nC)
reg.cell_weights = wrGlobal
# 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=30,
tolCG=1e-3)
# Create the default L2 inverse problem from the above objects
invProb = InvProblem.BaseInvProblem(ComboMisfit, reg, opt)
# Specify how the initial beta is found
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1)
# Target misfit to stop the inversion,
# try to fit as much as possible of the signal, we don't want to lose anything
targetMisfit = Directives.TargetMisfit(chifact=targetChi)
# Pre-conditioner
update_Jacobi = Directives.UpdatePreconditioner()
survey_inv.set_active_interval(1e-3, 1e-2)
survey_inv.dobs = fields_tot[survey_inv.t_active]
survey_inv.std = 0.05 * np.abs(fields_tot[survey_inv.t_active])
survey_inv.eps = 1e-11
# Setup and run inversion
dmis = DataMisfit.l2_DataMisfit(survey_inv)
w = mkvc((np.sum(np.array(problem_inv.A)**2, axis=0)))**0.5
w = w / np.max(w)
reg = Regularization.Simple(mesh=mesh,
indActive=actCells,
alpha_s=0.25,
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)
xi_0 = 1e-3 * np.ones(actCells.sum())
xi_rec = inv.run(xi_0)
# Predict VRM response at all times for recovered model
survey_inv.set_active_interval(0., 1.)
fields_pre = survey_inv.dpred(xi_rec)
def run(N=100, plotIt=True):
np.random.seed(1)
std_noise = 1e-2
mesh = Mesh.TensorMesh([N])
m0 = np.ones(mesh.nC) * 1e-4
mref = np.zeros(mesh.nC)
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.dobs = prob.fields(mtrue) + std_noise * np.random.randn(nk)
wd = np.ones(nk) * std_noise
# Distance weighting
wr = np.sum(prob.G**2., axis=0)**0.5
wr = wr / np.max(wr)
dmis = DataMisfit.l2_DataMisfit(survey)
dmis.Wd = 1. / wd
betaest = Directives.BetaEstimate_ByEig(beta0_ratio=1e-2)
reg = Regularization.Sparse(mesh)
reg.mref = mref
reg.cell_weights = wr
reg.mref = np.zeros(mesh.nC)
opt = Optimization.ProjectedGNCG(maxIter=100,
lower=-2.,
upper=2.,
maxIterLS=20,
maxIterCG=10,
tolCG=1e-3)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
update_Jacobi = Directives.Update_lin_PreCond()
# Set the IRLS directive, penalize the lowest 25 percentile of model values
# Start with an l2-l2, then switch to lp-norms
norms = [0., 0., 2., 2.]
IRLS = Directives.Update_IRLS(norms=norms,
prctile=25,
maxIRLSiter=15,
minGNiter=3)
inv = Inversion.BaseInversion(invProb,
directiveList=[IRLS, betaest, update_Jacobi])
# Run inversion
mrec = inv.run(m0)
print("Final misfit:" + str(invProb.dmisfit.eval(mrec)))
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(mesh.vectorCCx, mtrue, 'b-')
axes[1].plot(mesh.vectorCCx, reg.l2model, 'r-')
# axes[1].legend(('True Model', 'Recovered Model'))
axes[1].set_ylim(-1.0, 1.25)
axes[1].plot(mesh.vectorCCx, mrec, 'k-', lw=2)
axes[1].legend(('True Model', 'Smooth l2-l2',
'Sparse lp: {0}, lqx: {1}'.format(*reg.norms)),
fontsize=12)
return prob, survey, mesh, mrec
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):
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])
mstart = np.ones(nC) * 1e-4
mref = np.zeros(nC)
# Create a regularization
reg = Regularization.Sparse(mesh,
indActive=actv,
mapping=Maps.IdentityMap(nP=nC))
reg.cell_weights = wrGlobal
reg.norms = np.c_[driver.lpnorms].T
reg.mref = mref
# Add directives to the inversion
opt = Optimization.ProjectedGNCG(maxIter=100,
lower=-10.,
upper=10.,
maxIterCG=20,
tolCG=1e-3)
invProb = InvProblem.BaseInvProblem(ComboMisfit, reg, opt)
betaest = Directives.BetaEstimate_ByEig()
# Here is where the norms are applied
IRLS = Directives.Update_IRLS(f_min_change=1e-3, minGNiter=1)
update_Jacobi = Directives.UpdateJacobiPrecond()
targetMisfit = Directives.TargetMisfit()
saveModel = Directives.SaveUBCModelEveryIteration(mapping=actvMap)
saveModel.fileName = work_dir + out_dir + 'GRAV'
inv = Inversion.BaseInversion(
reg_t = Regularization.Sparse(regMesh, mapping=wires.t)
reg_t.cell_weights = wires.t * wr
reg_t.norms = [2, 2, 2, 2]
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=10,
lower=-10.,
upper=10.,
maxIterCG=20,
tolCG=1e-3)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt, beta=1e+5)
betaest = Directives.BetaEstimate_ByEig()
# Here is where the norms are applied
IRLS = Directives.Update_IRLS(f_min_change=1e-4, minGNiter=3, beta_tol=1e-2)
update_Jacobi = Directives.UpdateJacobiPrecond()
targetMisfit = Directives.TargetMisfit()
saveModel = Directives.SaveUBCModelEveryIteration(mapping=actvMap)
saveModel.fileName = work_dir + out_dir + 'MVI_C'
inv = Inversion.BaseInversion(invProb,
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$^3$)')
reg_t = Regularization.Sparse(mesh, indActive=actv, mapping=wires.t)
reg_t.cell_weights = wires.t * wr
reg_t.norms = [2, 2, 2, 2]
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=10,
lower=-10.,
upper=10.,
maxIterCG=20,
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=3, beta_tol=1e-2)
update_Jacobi = Directives.UpdatePreCond()
targetMisfit = Directives.TargetMisfit()
saveModel = Directives.SaveUBCModelEveryIteration(mapping=actvMap)
saveModel.fileName = work_dir + out_dir + 'MVI_C'
inv = Inversion.BaseInversion(
regMesh = Mesh.TensorMesh([nC])
reg_m1 = Regularization.Sparse(regMesh, mapping=wires.h**o)
reg_m1.cell_weights = wires.h**o*wr*2.
reg_m1.mref = mref
# Regularization for the voxel model
reg_m2 = Regularization.Sparse(mesh, indActive=actv, mapping=wires.hetero)
reg_m2.cell_weights = wires.hetero*wr
reg_m2.norms = np.c_[driver.lpnorms].T
reg_m2.mref = mref
reg = reg_m1 + reg_m2
opt = Optimization.ProjectedGNCG(maxIter=30, lower=driver.bounds[0],
upper=driver.bounds[1],
maxIterLS = 20, maxIterCG= 30,
tolCG = 1e-4)
invProb = InvProblem.BaseInvProblem(dmis, reg, opt)
betaest = Directives.BetaEstimate_ByEig(beta0_ratio = 1.)
IRLS = Directives.Update_IRLS(f_min_change=1e-4, minGNiter=2)
update_Jacobi = Directives.UpdatePreconditioner()
#saveModel = Directives.SaveUBCModelEveryIteration(mapping=actvMap*sumMap)
#saveModel.fileName = work_dir + dsep + out_dir + 'GRAV'
saveDict = Directives.SaveOutputDictEveryIteration()
inv = Inversion.BaseInversion(invProb, directiveList=[betaest, IRLS, saveDict,
update_Jacobi])
# Run inversion
mrec = inv.run(mstart)
chiMap=idenMap,
actInd=surf,
equiSourceLayer=True)
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=500,
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)
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()
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 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(-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)
# Create 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.mref = np.zeros(nC)
reg.norms = np.c_[0, 0, 0, 0]
# reg.eps_p, reg.eps_q = 1e-0, 1e-0
# 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=20,
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=40)
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 = -5
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
# Plot the data
Utils.PlotUtils.plot2Ddata(rxLoc, 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')
# 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,
0,
'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)
