Files
simpeg/SimPEG/ObjFunction.py
T
rowanc1 ab249d31b3 Parameters --> Rules
See the Linear example for updates on how to migrate to this version.
2014-05-14 14:30:33 -07:00

221 lines
7.1 KiB
Python

import Utils, Survey, Problem, numpy as np, scipy.sparse as sp, gc
class BaseObjFunction(object):
"""BaseObjFunction(forward, reg, **kwargs)"""
__metaclass__ = Utils.SimPEGMetaClass
beta = 1.0 #: Regularization trade-off parameter
debug = False #: Print debugging information
counter = None #: Set this to a SimPEG.Utils.Counter() if you want to count things
surveyPair = Survey.BaseSurvey
problemPair = Problem.BaseProblem
name = 'Base Objective Function' #: Name of the objective function
u_current = None #: The most current evaluated field
m_current = None #: The most current model
@property
def parent(self):
"""This is the parent of the objective function."""
return getattr(self,'_parent',None)
@parent.setter
def parent(self, p):
if getattr(self,'_parent',None) is not None:
print 'Objective function has switched to a new parent!'
self._parent = p
@property
def inv(self): return self.parent
@property
def objFunc(self): return self
@property
def opt(self): return getattr(self.parent,'opt',None)
def __init__(self, forward, reg, **kwargs):
Utils.setKwargs(self, **kwargs)
assert forward.ispaired, 'The forward problem and survey must be paired.'
if isinstance(forward, self.surveyPair):
self.survey = forward
self.prob = forward.prob
elif isinstance(forward, self.problemPair):
self.prob = forward
self.survey = forward.survey
self.reg = reg
self.reg.parent = self
@Utils.callHooks('startup')
def startup(self, m0):
"""startup(m0)
Called when inversion is first starting.
"""
if self.debug: print 'Calling ObjFunction.startup'
if self.reg.mref is None:
print 'Regularization has not set mref. SimPEG.ObjFunction will set it to m0.'
self.reg.mref = m0
self.phi_d = np.nan
self.phi_m = np.nan
self.m_current = m0
@Utils.timeIt
def evalFunction(self, m, return_g=True, return_H=True):
"""evalFunction(m, return_g=True, return_H=True)
"""
self.u_current = None
self.m_current = m
gc.collect()
u = self.prob.fields(m)
self.u_current = u
phi_d = self.dataObj(m, u=u)
phi_m = self.reg.modelObj(m)
self.dpred = self.survey.dpred(m, u=u) # This is a cheap matrix vector calculation.
self.phi_d, self.phi_d_last = phi_d, self.phi_d
self.phi_m, self.phi_m_last = phi_m, self.phi_m
f = phi_d + self.beta * phi_m
out = (f,)
if return_g:
phi_dDeriv = self.dataObjDeriv(m, u=u)
phi_mDeriv = self.reg.modelObjDeriv(m)
g = phi_dDeriv + self.beta * phi_mDeriv
out += (g,)
if return_H:
def H_fun(v):
phi_d2Deriv = self.dataObj2Deriv(m, v, u=u)
phi_m2Deriv = self.reg.modelObj2Deriv(m, v=v)
return phi_d2Deriv + self.beta * phi_m2Deriv
operator = sp.linalg.LinearOperator( (m.size, m.size), H_fun, dtype=m.dtype )
out += (operator,)
return out if len(out) > 1 else out[0]
@Utils.timeIt
def dataObj(self, m, u=None):
"""dataObj(m, u=None)
:param numpy.array m: geophysical model
:param numpy.array u: fields
:rtype: float
:return: data misfit
The data misfit using an l_2 norm is:
.. math::
\mu_\\text{data} = {1\over 2}\left| \mathbf{W} \circ (\mathbf{d}_\\text{pred} - \mathbf{d}_\\text{obs}) \\right|_2^2
Where P is a projection matrix that brings the field on the full domain to the data measurement locations;
u is the field of interest; d_obs is the observed data; and W is the weighting matrix.
"""
# TODO: ensure that this is a data is vector and Wd is a matrix.
R = self.survey.residualWeighted(m, u=u)
return 0.5*np.vdot(R, R)
@Utils.timeIt
def dataObjDeriv(self, m, u=None):
"""dataObjDeriv(m, u=None)
:param numpy.array m: geophysical model
:param numpy.array u: fields
:rtype: numpy.array
:return: data misfit derivative
The data misfit using an l_2 norm is:
.. math::
\mu_\\text{data} = {1\over 2}\left| \mathbf{W} \circ (\mathbf{d}_\\text{pred} - \mathbf{d}_\\text{obs}) \\right|_2^2
If the field, u, is provided, the calculation of the data is fast:
.. math::
\mathbf{d}_\\text{pred} = \mathbf{Pu(m)}
\mathbf{R} = \mathbf{W} \circ (\mathbf{d}_\\text{pred} - \mathbf{d}_\\text{obs})
Where P is a projection matrix that brings the field on the full domain to the data measurement locations;
u is the field of interest; d_obs is the observed data; and W is the weighting matrix.
The derivative of this, with respect to the model, is:
.. math::
\\frac{\partial \mu_\\text{data}}{\partial \mathbf{m}} = \mathbf{J}^\\top \mathbf{W \circ R}
"""
if u is None: u = self.prob.fields(m)
R = self.survey.residualWeighted(m, u=u)
dmisfit = self.prob.Jtvec(m, self.survey.Wd * R, u=u)
return dmisfit
@Utils.timeIt
def dataObj2Deriv(self, m, v, u=None):
"""dataObj2Deriv(m, v, u=None)
:param numpy.array m: geophysical model
:param numpy.array v: vector to multiply
:param numpy.array u: fields
:rtype: numpy.array
:return: data misfit derivative
The data misfit using an l_2 norm is:
.. math::
\mu_\\text{data} = {1\over 2}\left| \mathbf{W} \circ (\mathbf{d}_\\text{pred} - \mathbf{d}_\\text{obs}) \\right|_2^2
If the field, u, is provided, the calculation of the data is fast:
.. math::
\mathbf{d}_\\text{pred} = \mathbf{Pu(m)}
\mathbf{R} = \mathbf{W} \circ (\mathbf{d}_\\text{pred} - \mathbf{d}_\\text{obs})
Where P is a projection matrix that brings the field on the full domain to the data measurement locations;
u is the field of interest; d_obs is the observed data; and W is the weighting matrix.
The derivative of this, with respect to the model, is:
.. math::
\\frac{\partial \mu_\\text{data}}{\partial \mathbf{m}} = \mathbf{J}^\\top \mathbf{W \circ R}
\\frac{\partial^2 \mu_\\text{data}}{\partial^2 \mathbf{m}} = \mathbf{J}^\\top \mathbf{W \circ W J}
"""
if u is None: u = self.prob.fields(m)
R = self.survey.residualWeighted(m, u=u)
# TODO: abstract to different norms a little cleaner.
# \/ it goes here. in l2 it is the identity.
dmisfit = self.prob.Jtvec_approx(m, self.survey.Wd * self.survey.Wd * self.prob.Jvec_approx(m, v, u=u), u=u)
return dmisfit