Files
simpeg/simpegEM/FDEM/FDEM.py
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472 lines
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Python

from SimPEG import Survey, Problem, Utils, np, sp, Solver as SimpegSolver
from scipy.constants import mu_0
from SurveyFDEM import SurveyFDEM
from FieldsFDEM import FieldsFDEM, FieldsFDEM_e, FieldsFDEM_b, FieldsFDEM_h, FieldsFDEM_j
from simpegEM.Base import BaseEMProblem
from simpegEM.Utils.EMUtils import omega
class BaseFDEMProblem(BaseEMProblem):
"""
We start by looking at Maxwell's equations in the electric field \\(\\vec{E}\\) and the magnetic flux density \\(\\vec{B}\\):
.. math::
\\nabla \\times \\vec{E} + i \\omega \\vec{B} = \\vec{S_m} \\\\
\\nabla \\times \\mu^{-1} \\vec{B} - \\sigma \\vec{E} = \\vec{S_e}
"""
surveyPair = SurveyFDEM
fieldsPair = FieldsFDEM
def forward(self, m, RHS):
F = self.fieldsPair(self.mesh, self.survey)
for freq in self.survey.freqs:
A = self.getA(freq)
rhs = RHS(freq)
Ainv = self.Solver(A, **self.solverOpts)
sol = Ainv * rhs
Srcs = self.survey.getSrcByFreq(freq)
F[Srcs, self._fieldType] = sol
return F
def Jvec(self, m, v, u=None):
if u is None:
u = self.fields(m)
self.curModel = m
Jv = self.dataPair(self.survey)
for freq in self.survey.freqs:
A = self.getA(freq)
Ainv = self.Solver(A, **self.solverOpts)
for src in self.survey.getSource(freq):
u_src = u[src, self.solType]
w = self.getADeriv(freq, u_src, v)
Ainvw = Ainv * w
for rx in src.rxList:
fAinvw = self.calcFields(Ainvw, freq, rx.projField)
P = lambda v: rx.projectFieldsDeriv(src, self.mesh, u, v)
Jv[src, rx] = - P(fAinvw)
df_dm = self.calcFieldsDeriv(u_src, freq, rx.projField, v)
if df_dm is not None:
Jv[src, rx] += P(df_dm)
return Utils.mkvc(Jv)
def Jtvec(self, m, v, u=None):
if u is None:
u = self.fields(m)
self.curModel = m
# Ensure v is a data object.
if not isinstance(v, self.dataPair):
v = self.dataPair(self.survey, v)
Jtv = np.zeros(self.mapping.nP)
for freq in self.survey.freqs:
AT = self.getA(freq).T
ATinv = self.Solver(AT, **self.solverOpts)
for src in self.survey.getSource(freq):
u_src = u[src, self.solType]
for rx in src.rxList:
PTv = rx.projectFieldsDeriv(src, self.mesh, u, v[src, rx], adjoint=True)
fPTv = self.calcFields(PTv, freq, rx.projField, adjoint=True)
w = ATinv * fPTv
Jtv_rx = - self.getADeriv(freq, u_src, w, adjoint=True)
df_dm = self.calcFieldsDeriv(u_src, freq, rx.projField, PTv, adjoint=True)
if df_dm is not None:
Jtv_rx += df_dm
real_or_imag = rx.projComp
if real_or_imag == 'real':
Jtv += Jtv_rx.real
elif real_or_imag == 'imag':
Jtv += - Jtv_rx.real
else:
raise Exception('Must be real or imag')
return Jtv
def getSourceTerm(self, freq):
"""
:param float freq: Frequency
:rtype: numpy.ndarray (nE or nF, nSrc)
:return: RHS
"""
Srcs = self.survey.getSrcByFreq(freq)
if self._eqLocs is 'FE':
S_m = np.zeros((self.mesh.nF,len(Srcs)), dtype=complex)
S_e = np.zeros((self.mesh.nE,len(Srcs)), dtype=complex)
elif self._eqLocs is 'EF':
S_m = np.zeros((self.mesh.nE,len(Srcs)), dtype=complex)
S_e = np.zeros((self.mesh.nF,len(Srcs)), dtype=complex)
for i, src in enumerate(Srcs):
smi, sei = src.eval(self)
if smi is not None:
S_m[:,i] = smi
if sei is not None:
S_e[:,i] = sei
return S_m, S_e
def getSourceTermDeriv(self,freq,m,v,u=None,adjoint=False):
raise NotImplementedError('getSourceTermDeriv not implemented yet')
return None, None
##########################################################################################
################################ E-B Formulation #########################################
##########################################################################################
class ProblemFDEM_e(BaseFDEMProblem):
"""
By eliminating the magnetic flux density using
.. math::
\\vec{B} = \\frac{-1}{i\\omega}\\nabla\\times\\vec{E},
we can write Maxwell's equations as a second order system in \\ \\vec{E} \\ only:
.. math::
\\nabla \\times \\mu^{-1} \\nabla \\times \\vec{E} + i \\omega \\sigma \\vec{E} = \\vec{J_s}
This is the definition of the Forward Problem using the E-formulation of Maxwell's equations.
"""
_fieldType = 'e'
_eqLocs = 'FE'
fieldsPair = FieldsFDEM_e
def __init__(self, mesh, **kwargs):
BaseFDEMProblem.__init__(self, mesh, **kwargs)
def getA(self, freq):
"""
:param float freq: Frequency
:rtype: scipy.sparse.csr_matrix
:return: A
"""
mui = self.MfMui
sig = self.MeSigma
C = self.mesh.edgeCurl
return C.T*mui*C + 1j*omega(freq)*sig
def getADeriv(self, freq, u, v, adjoint=False):
sig = self.curModel.transform
dsig_dm = self.curModel.transformDeriv
dMe_dsig = self.mesh.getEdgeInnerProductDeriv(sig)(u)
if adjoint:
return 1j * omega(freq) * ( dsig_dm.T * ( dMe_dsig.T * v ) )
return 1j * omega(freq) * ( dMe_dsig * ( dsig_dm * v ) )
def getRHS(self, freq):
"""
:param float freq: Frequency
:rtype: numpy.ndarray (nE, nSrc)
:return: RHS
"""
S_m, S_e = self.getSourceTerm(freq)
C = self.mesh.edgeCurl
MfMui = self.MfMui
RHS = C.T * (MfMui * S_m) -1j*omega(freq)*S_e
return RHS
def getRHSDeriv(self, freq, u, v, adjoint=False):
raise NotImplementedError('getRHSDeriv not implemented yet')
return None
class ProblemFDEM_b(BaseFDEMProblem):
"""
Solving for b!
"""
_fieldType = 'b'
_eqLocs = 'FE'
fieldsPair = FieldsFDEM_b
def __init__(self, mesh, **kwargs):
BaseFDEMProblem.__init__(self, mesh, **kwargs)
def getA(self, freq):
"""
:param float freq: Frequency
:rtype: scipy.sparse.csr_matrix
:return: A
"""
mui = self.MfMui
sigI = self.MeSigmaI
C = self.mesh.edgeCurl
iomega = 1j * omega(freq) * sp.eye(self.mesh.nF)
A = C*sigI*C.T*mui + iomega
if self._makeASymmetric is True:
return mui.T*A
return A
def getADeriv(self, freq, u, v, adjoint=False):
mui = self.MfMui
C = self.mesh.edgeCurl
sig = self.curModel.transform
dsig_dm = self.curModel.transformDeriv
dMeSigmaI_dI = self._dMeSigmaI_dI
vec = (C.T*(mui*u))
dMe_dsig = self.mesh.getEdgeInnerProductDeriv(sig)(vec)
if adjoint:
if self._makeASymmetric is True:
v = mui * v
return dsig_dm.T * ( dMe_dsig.T * ( dMeSigmaI_dI.T * ( C.T * v ) ) )
if self._makeASymmetric is True:
return mui.T * ( C * ( dMeSigmaI_dI * ( dMe_dsig * ( dsig_dm * v ) ) ) )
return C * ( dMeSigmaI_dI * ( dMe_dsig * ( dsig_dm * v ) ) )
def getRHS(self, freq):
"""
:param float freq: Frequency
:rtype: numpy.ndarray (nE, nSrc)
:return: RHS
"""
S_m, S_e = self.getSourceTerm(freq)
C = self.mesh.edgeCurl
MeSigmaI = self.MeSigmaI
RHS = S_m + C * ( MeSigmaI * S_e )
if self._makeASymmetric is True:
mui = self.MfMui
return mui.T*RHS
return RHS
def getRHSDeriv(self, freq, u, v, adjoint=False):
raise NotImplementedError('getRHSDeriv not implemented yet')
return None
##########################################################################################
################################ H-J Formulation #########################################
##########################################################################################
class ProblemFDEM_j(BaseFDEMProblem):
"""
Using the H-J formulation of Maxwell's equations
.. math::
\\nabla \\times \\sigma^{-1} \\vec{J} + i\\omega\\mu\\vec{H} = 0
\\nabla \\times \\vec{H} - \\vec{J} = \\vec{J_s}
Since \(\\vec{J}\) is a flux and \(\\vec{H}\) is a field, we discretize \(\\vec{J}\) on faces and \(\\vec{H}\) on edges.
For this implementation, we solve for J using \( \\vec{H} = - (i\\omega\\mu)^{-1} \\nabla \\times \\sigma^{-1} \\vec{J} \) :
.. math::
\\nabla \\times ( \\mu^{-1} \\nabla \\times \\sigma^{-1} \\vec{J} ) + i\\omega \\vec{J} = - i\\omega\\vec{J_s}
We discretize this to:
.. math::
(\\mathbf{C} \\mathbf{M^e_{mu^{-1}}} \\mathbf{C^T} \\mathbf{M^f_{\\sigma^{-1}}} + i\\omega ) \\mathbf{j} = - i\\omega \\mathbf{j_s}
.. note::
This implementation does not yet work with full anisotropy!!
"""
_fieldType = 'j'
_eqLocs = 'EF'
fieldsPair = FieldsFDEM_j
def __init__(self, mesh, **kwargs):
BaseFDEMProblem.__init__(self, mesh, **kwargs)
def getA(self, freq):
"""
Here, we form the operator \(\\mathbf{A}\) to solce
.. math::
\\mathbf{A} = \\mathbf{C} \\mathbf{M^e_{mu^{-1}}} \\mathbf{C^T} \\mathbf{M^f_{\\sigma^{-1}}} + i\\omega
:param float freq: Frequency
:rtype: scipy.sparse.csr_matrix
:return: A
"""
MeMuI = self.MeMuI
MfSigi = self.MfSigmai
C = self.mesh.edgeCurl
iomega = 1j * omega(freq) * sp.eye(self.mesh.nF)
A = C * MeMuI * C.T * MfSigi + iomega
if self._makeASymmetric is True:
return MfSigi.T*A
return A
def getADeriv(self, freq, u, v, adjoint=False):
"""
In this case, we assume that electrical conductivity, \(\\sigma\) is the physical property of interest (i.e. \(\sigma\) = model.transform). Then we want
.. math::
\\frac{\mathbf{A(\\sigma)} \mathbf{v}}{d \\mathbf{m}} &= \\mathbf{C} \\mathbf{M^e_{mu^{-1}}} \\mathbf{C^T} \\frac{d \\mathbf{M^f_{\\sigma^{-1}}}}{d \\mathbf{m}}
&= \\mathbf{C} \\mathbf{M^e_{mu}^{-1}} \\mathbf{C^T} \\frac{d \\mathbf{M^f_{\\sigma^{-1}}}}{d \\mathbf{\\sigma^{-1}}} \\frac{d \\mathbf{\\sigma^{-1}}}{d \\mathbf{\\sigma}} \\frac{d \\mathbf{\\sigma}}{d \\mathbf{m}}
"""
MeMuI = self.MeMuI
MfSigi = self.MfSigmai
C = self.mesh.edgeCurl
sig = self.curModel.transform
sigi = 1/sig
dsig_dm = self.curModel.transformDeriv
dsigi_dsig = -Utils.sdiag(sigi)**2
dMf_dsigi = self.mesh.getFaceInnerProductDeriv(sigi)(u)
if adjoint:
if self._makeASymmetric is True:
v = MfSigi * v
return dsig_dm.T * ( dsigi_dsig.T *( dMf_dsigi.T * ( C * ( MeMuI.T * ( C.T * v ) ) ) ) )
if self._makeASymmetric is True:
return MfSigi.T * ( C * ( MeMuI * ( C.T * ( dMf_dsigi * ( dsigi_dsig * ( dsig_dm * v ) ) ) ) ) )
return C * ( MeMuI * ( C.T * ( dMf_dsigi * ( dsigi_dsig * ( dsig_dm * v ) ) ) ) )
def getRHS(self, freq):
"""
:param float freq: Frequency
:rtype: numpy.ndarray (nE, nSrc)
:return: RHS
"""
S_m, S_e = self.getSourceTerm(freq)
C = self.mesh.edgeCurl
MeMuI = self.MeMuI
RHS = C * (MeMuI * S_m) - 1j * omega(freq) * S_e
if self._makeASymmetric is True:
MfSigi = self.MfSigmai
return MfSigi.T*RHS
return RHS
def getRHSDeriv(self, freq, u, v, adjoint=False):
raise NotImplementedError('getRHSDeriv not implemented yet')
return None
class ProblemFDEM_h(BaseFDEMProblem):
"""
Using the H-J formulation of Maxwell's equations
.. math::
\\nabla \\times \\sigma^{-1} \\vec{J} + i\\omega\\mu\\vec{H} = 0
\\nabla \\times \\vec{H} - \\vec{J} = \\vec{J_s}
Since \(\\vec{J}\) is a flux and \(\\vec{H}\) is a field, we discretize \(\\vec{J}\) on faces and \(\\vec{H}\) on edges.
For this implementation, we solve for J using \( \\vec{J} = \\nabla \\times \\vec{H} - \\vec{J_s} \)
.. math::
\\nabla \\times \\sigma^{-1} \\nabla \\times \\vec{H} + i\\omega\\mu\\vec{H} = \\nabla \\times \\sigma^{-1} \\vec{J_s}
We discretize and solve
.. math::
(\\mathbf{C^T} \\mathbf{M^f_{\\sigma^{-1}}} \\mathbf{C} + i\\omega \\mathbf{M_{\mu}} ) \\mathbf{h} = \\mathbf{C^T} \\mathbf{M^f_{\\sigma^{-1}}} \\vec{J_s}
.. note::
This implementation does not yet work with full anisotropy!!
"""
_fieldType = 'h'
_eqLocs = 'EF'
fieldsPair = FieldsFDEM_h
def __init__(self, mesh, **kwargs):
BaseFDEMProblem.__init__(self, mesh, **kwargs)
def getA(self, freq):
"""
:param float freq: Frequency
:rtype: scipy.sparse.csr_matrix
:return: A
"""
MeMu = self.MeMu
MfSigi = self.MfSigmai
C = self.mesh.edgeCurl
return C.T * MfSigi * C + 1j*omega(freq)*MeMu
def getADeriv(self, freq, u, v, adjoint=False):
MeMu = self.MeMu
C = self.mesh.edgeCurl
sig = self.curModel.transform
sigi = 1/sig
dsig_dm = self.curModel.transformDeriv
dsigi_dsig = -Utils.sdiag(sigi)**2
dMf_dsigi = self.mesh.getFaceInnerProductDeriv(sigi)(C*u)
if adjoint:
return (dsig_dm.T * (dsigi_dsig.T * (dMf_dsigi.T * (C * v))))
return (C.T * (dMf_dsigi * (dsigi_dsig * (dsig_dm * v))))
def getRHS(self, freq):
"""
:param float freq: Frequency
:rtype: numpy.ndarray (nE, nSrc)
:return: RHS
"""
S_m, S_e = self.getSourceTerm(freq)
C = self.mesh.edgeCurl
MfSigmai = self.MfSigmai
RHS = S_m + C.T * ( MfSigmai * S_e )
return RHS
def getRHSDeriv(self, freq, u, v, adjoint=False):
raise NotImplementedError('getRHSDeriv not implemented yet')
return None