Files
simpeg/simpegEM/TDEM/TDEM_b.py
T
2014-02-12 16:59:56 -08:00

137 lines
4.1 KiB
Python

from BaseTDEM import ProblemBaseTDEM
from FieldsTDEM import FieldsTDEM
import numpy as np
class ProblemTDEM_b(ProblemBaseTDEM):
"""
Time-Domain EM problem - B-formulation
.. math::
\dcurl \e^{(t+1)} + \\frac{\\b^{(t+1)} - \\b^{(t)}}{\delta t} = 0 \\\\
\dcurl^\\top \MfMui \\b^{(t+1)} - \MeSig \e^{(t+1)} = \Me \j_s^{(t+1)}
"""
def __init__(self, mesh, model, **kwargs):
ProblemBaseTDEM.__init__(self, mesh, model, **kwargs)
solType = 'b'
####################################################
# Internal Methods
####################################################
def getA(self, tInd):
"""
:param int tInd: Time index
:rtype: scipy.sparse.csr_matrix
:return: A
"""
dt = self.getDt(tInd)
return self.MfMui*self.mesh.edgeCurl*self.MeSigmaI*self.mesh.edgeCurl.T*self.MfMui + (1/dt)*self.MfMui
def getRHS(self, tInd, F):
dt = self.getDt(tInd)
return (1/dt)*self.MfMui*F.get_b(tInd-1)
####################################################
# Derivatives
####################################################
def J(self, m, v, u=None):
if u is None:
u = self.fields(m)
p = self.G(m, v, u)
y = self.solveAh(m, p)
return self.data.projectFields(y)
def G(self, m, v, u=None):
if u is None:
u = self.fields(m)
p = FieldsTDEM(self.mesh, 1, self.times.size, 'b')
c = self.mesh.getEdgeMassDeriv()*self.model.transformDeriv(m)*v
for i in range(self.times.size):
ei = u.get_e(i)
pVal = np.empty_like(ei)
for j in range(ei.shape[1]):
pVal[:,j] = -ei[:,j]*c
p.set_e(pVal,i)
p.set_b(np.zeros((self.mesh.nF,1)), i)
return p
def solveAh(self, m, p):
def AhRHS(tInd, u):
rhs = self.MfMui*self.mesh.edgeCurl*self.MeSigmaI*p.get_e(tInd) + self.MfMui*p.get_b(tInd)
if tInd == 0:
return rhs
dt = self.getDt(tInd)
return rhs + 1./dt*self.MfMui*u.get_b(tInd-1)
def AhCalcFields(sol, solType, tInd):
b = sol
e = self.MeSigmaI*self.mesh.edgeCurl.T*self.MfMui*b - self.MeSigmaI*p.get_e(tInd)
return {'b':b, 'e':e}
Y = self.fields(m, useThisRhs=AhRHS, useThisCalcFields=AhCalcFields)
return Y
####################################################
# Functions for tests
####################################################
def AhVec(self, m, u=None):
if u is None:
u = self.fields(m)
self.makeMassMatrices(m)
dt = self.getDt(0)
b = 1/dt*u.get_b(0) + self.mesh.edgeCurl*u.get_e(0)
e = self.mesh.edgeCurl.T*self.MfMui*u.get_b(0) - self.MeSigma*u.get_e(0)
f = FieldsTDEM(self.mesh, 1, self.times.size, 'b')
f.set_b(b, 0)
f.set_e(e, 0)
for i in range(1,self.times.size):
dt = self.getDt(i)
b = 1/dt*u.get_b(i) + self.mesh.edgeCurl*u.get_e(i) - 1/dt*u.get_b(i-1)
e = self.mesh.edgeCurl.T*self.MfMui*u.get_b(i) - self.MeSigma*u.get_e(i)
f.set_b(b, i)
f.set_e(e, i)
return f
if __name__ == '__main__':
from SimPEG import *
import simpegEM as EM
from simpegEM.Utils.Ana import hzAnalyticDipoleT
from scipy.constants import mu_0
import matplotlib.pyplot as plt
cs = 5.
ncx = 20
ncy = 6
npad = 20
hx = Utils.meshTensors(((0,cs), (ncx,cs), (npad,cs)))
hy = Utils.meshTensors(((npad,cs), (ncy,cs), (npad,cs)))
mesh = Mesh.Cyl1DMesh([hx,hy], -hy.sum()/2)
model = Model.Vertical1DModel(mesh)
opts = {'txLoc':0.,
'txType':'VMD_MVP',
'rxLoc':np.r_[150., 0.],
'rxType':'bz',
'timeCh':np.logspace(-4,-2,20),
}
dat = EM.TDEM.DataTDEM1D(**opts)
prb = EM.TDEM.ProblemTDEM_b(mesh, model)
# prb.setTimes([1e-5, 5e-5, 2.5e-4], [150, 150, 150])
# prb.setTimes([1e-5, 5e-5, 2.5e-4], [10, 10, 10])
prb.setTimes([1e-5], [1])
prb.pair(dat)
sigma = np.random.rand(mesh.nCz)