def test01_alt(self):
"""Set directory"""
if isdir(self.myoutdir):
os.system('rm -rf {0}'.format(self.myoutdir))
myplot = PlotFenics()
myplot.set_outdir(self.myoutdir)
self.assertTrue(isdir(self.myoutdir))
def test01_alt(self):
"""Set directory"""
if isdir(self.myoutdir):
os.system('rm -rf {0}'.format(self.myoutdir))
myplot = PlotFenics()
myplot.set_outdir(self.myoutdir)
self.assertTrue(isdir(self.myoutdir))
def test05(self):
"""Indices list properly created"""
myplot = PlotFenics(self.myoutdir)
myplot.set_varname('testm')
for ii in self.indexlist:
self.m.vector()[:] = ii * np.ones(self.lenm, dtype='float')
myplot.plot_vtk(self.m, ii)
self.assertTrue(myplot.indices == self.indexlist)
def test04(self):
"""Plot parameter m"""
myplot = PlotFenics(self.myoutdir)
myplot.set_varname('testm')
self.m.vector()[:] = 20 * np.ones(self.lenm, dtype='float')
myplot.plot_vtk(self.m, 20)
self.assertTrue(isfile(self.myoutdir+'testm_20.pvd') and \
isfile(self.myoutdir+'testm_20000000.vtu'))
def solvefwd(self, cost=False):
"""Solve fwd operators for given RHS"""
self.nbfwdsolves += 1
if self.ObsOp.noise: self.noise = 0.0
if self.plot:
self.plotu = PlotFenics(self.plotoutdir)
self.plotu.set_varname('u{0}'.format(self.nbfwdsolves))
if cost: self.misfit = 0.0
for ii, rhs in enumerate(self.RHS):
self.solve_A(self.u.vector(), rhs)
if self.plot: self.plotu.plot_vtk(self.u, ii)
u_obs, noiselevel = self.ObsOp.obs(self.u)
self.U.append(u_obs)
if self.ObsOp.noise: self.noise += noiselevel
if cost:
self.misfit += self.ObsOp.costfct(u_obs, self.UD[ii])
self.C.append(assemble(self.c))
if cost:
self.misfit /= len(self.U)
self.regul = self.Regul.cost(self.m)
self.cost = self.misfit + self.regul
if self.ObsOp.noise and self.myrank == 0:
print 'Total noise in data misfit={:.5e}\n'.\
format(self.noise*.5/len(self.U))
self.ObsOp.noise = False # Safety
if self.plot: self.plotu.gather_vtkplots()
def _set_plots(self, plot):
self.plot = plot
if self.plot:
filename, ext = splitext(sys.argv[0])
self.plotoutdir = filename + '/Plots/'
self.plotvarm = PlotFenics(self.plotoutdir)
self.plotvarm.set_varname('m')
def test06(self):
"""Gather plots"""
myplot = PlotFenics(self.myoutdir)
myplot.set_varname('testm')
myplot.indices = self.indexlist
myplot.gather_vtkplots()
self.assertTrue(isfile(self.myoutdir + 'testm.pvd'))
def test09(self):
"""Indices are reset when varname changed"""
myplot = PlotFenics(self.myoutdir)
myplot.set_varname('testm')
indexlist = [1, 3]
for ii in indexlist:
self.m.vector()[:] = ii * np.ones(self.lenm, dtype='float')
myplot.plot_vtk(self.m, ii)
myplot.set_varname('testm2')
self.assertTrue((myplot.varname == 'testm2') and \
(myplot.indices == []))
def test06(self):
"""Gather plots"""
myplot = PlotFenics(self.myoutdir)
myplot.set_varname('testm')
myplot.indices = self.indexlist
myplot.gather_vtkplots()
self.assertTrue(isfile(self.myoutdir+'testm.pvd'))
def test09(self):
"""Indices are reset when varname changed"""
myplot = PlotFenics(self.myoutdir)
myplot.set_varname('testm')
indexlist = [1,3]
for ii in indexlist:
self.m.vector()[:] = ii * np.ones(self.lenm, dtype='float')
myplot.plot_vtk(self.m, ii)
myplot.set_varname('testm2')
self.assertTrue((myplot.varname == 'testm2') and \
(myplot.indices == []))
def test05(self):
"""Indices list properly created"""
myplot = PlotFenics(self.myoutdir)
myplot.set_varname('testm')
for ii in self.indexlist:
self.m.vector()[:] = ii * np.ones(self.lenm, dtype='float')
myplot.plot_vtk(self.m, ii)
self.assertTrue(myplot.indices == self.indexlist)
def test04(self):
"""Plot parameter m"""
myplot = PlotFenics(self.myoutdir)
myplot.set_varname('testm')
self.m.vector()[:] = 20 * np.ones(self.lenm, dtype='float')
myplot.plot_vtk(self.m, 20)
self.assertTrue(isfile(self.myoutdir+'testm_20.pvd') and \
isfile(self.myoutdir+'testm_20000000.vtu'))
def __init__(self, mesh, trueImage, parameters=[]):
"""
Inputs:
mesh = Fenics mesh
trueImage = object from class Image
parameters = dict
"""
# Mesh
self.mesh = mesh
self.V = dl.FunctionSpace(self.mesh, "Lagrange", 1)
self.xx = self.V.dofmap().tabulate_all_coordinates(self.mesh)
self.dimV = self.V.dim()
self.test, self.trial = dl.TestFunction(self.V), dl.TrialFunction(self.V)
self.f_true = dl.interpolate(trueImage, self.V)
self.g, self.dg, self.gtmp = dl.Function(self.V), dl.Function(self.V), dl.Function(self.V)
self.Grad = dl.Function(self.V)
self.Gradnorm0 = None
# mass matrix
self.Mweak = dl.inner(self.test, self.trial) * dl.dx
self.M = dl.assemble(self.Mweak)
self.solverM = dl.LUSolver("petsc")
self.solverM.parameters["symmetric"] = True
self.solverM.parameters["reuse_factorization"] = True
self.solverM.set_operator(self.M)
# identity matrix
self.I = dl.assemble(self.Mweak)
self.I.zero()
self.I.set_diagonal(dl.interpolate(dl.Constant(1), self.V).vector())
# self.targetnorm = np.sqrt((self.M*self.f_true.vector()).inner(self.f_true.vector()))
self.targetnorm = np.sqrt((self.f_true.vector()).inner(self.f_true.vector()))
# line search parameters
self.parameters = {"alpha0": 1.0, "rho": 0.5, "c": 5e-5, "max_backtrack": 12}
# regularization
self.parameters.update({"eps": 1e-4, "k": 1.0, "regularization": "TV", "mode": "primaldual"})
self.parameters.update(parameters)
self.define_regularization()
self.regparam = 1.0
# plots:
filename, ext = os.path.splitext(sys.argv[0])
if os.path.isdir(filename + "/"):
shutil.rmtree(filename + "/")
self.myplot = PlotFenics(filename)
def solveadj(self, grad=False):
"""Solve adj operators"""
self.nbadjsolves += 1
if self.plot:
self.plotp = PlotFenics(self.plotoutdir)
self.plotp.set_varname('p{0}'.format(self.nbadjsolves))
self.Nbsrc = len(self.UD)
if grad: self.MG.vector()[:] = np.zeros(self.lenm)
for ii, C in enumerate(self.C):
self.ObsOp.assemble_rhsadj(self.U[ii], self.UD[ii], \
self.rhs, self.bcadj)
self.solve_A(self.p.vector(), self.rhs.vector())
if self.plot: self.plotp.plot_vtk(self.p, ii)
self.E.append(assemble(self.e))
if grad: self.MG.vector().axpy(1.0/self.Nbsrc, \
C * self.p.vector())
if grad:
self.MG.vector().axpy(1.0, self.Regul.grad(self.m))
self.solverM.solve(self.Grad.vector(), self.MG.vector())
self.Gradnorm = np.sqrt(self.Grad.vector().inner(self.MG.vector()))
if self.plot: self.plotp.gather_vtkplots()
def test03(self):
"""Need index list defined to gather"""
myplot = PlotFenics(self.myoutdir)
myplot.set_varname('testm')
self.assertRaises(NoIndicesError, myplot.gather_vtkplots)
def test02_alt(self):
"""Need varname defined to plot"""
myplot = PlotFenics(self.myoutdir)
self.m.vector()[:] = np.ones(self.lenm)
self.assertRaises(NoVarnameError, myplot.plot_vtk, self.m)
def test02(self):
"""Instantiate class when dir exists"""
myplot = PlotFenics(self.myoutdir)
myplot.set_outdir(self.myoutdir + 'Test1/')
self.assertTrue(myplot.outdir == self.myoutdir + 'Test1/')
def test02(self):
"""Instantiate class when dir exists"""
myplot = PlotFenics(self.myoutdir)
myplot.set_outdir(self.myoutdir + 'Test1/')
self.assertTrue(myplot.outdir == self.myoutdir + 'Test1/')
def test01(self):
"""Instantiate class when dir does not exist"""
if isdir(self.myoutdir):
os.system('rm -rf {0}'.format(self.myoutdir))
myplot = PlotFenics(self.myoutdir)
self.assertTrue(isdir(self.myoutdir))
def test00_defdir(self):
"""Check default directory"""
if isdir(self.defoutdir):
os.system('rm -rf {0}'.format(self.defoutdir))
myplot = PlotFenics()
self.assertTrue(isdir(self.defoutdir))
def test00_inst(self):
"""Default instantiation"""
myplot = PlotFenics()
def test03(self):
"""Need index list defined to gather"""
myplot = PlotFenics(self.myoutdir)
myplot.set_varname('testm')
self.assertRaises(NoIndicesError, myplot.gather_vtkplots)
def test08(self):
"""Fenics_vtu_correction variable"""
myplot = PlotFenics(self.myoutdir)
self.assertTrue(isfile(self.myoutdir+'testm_20'+\
myplot.Fenics_vtu_correction+'.vtu'))
def __init__(self,
CGdeg,
regularizationtype,
h=1.0,
parameters=[],
image='image.dat'):
class Image(dl.Expression):
def __init__(self, Lx, Ly, data):
self.data = data
self.hx = Lx / float(self.data.shape[1] - 1)
self.hy = Ly / float(self.data.shape[0] - 1)
def eval(self, values, x):
j = math.floor(x[0] / self.hx)
i = math.floor(x[1] / self.hy)
values[0] = self.data[i, j]
data = np.loadtxt(image, delimiter=',')
#Lx, Ly = float(data.shape[1])/float(data.shape[0]), 1.
Lx, Ly = 2., 1.
scaling = 100. * h # =1.0 => h~0.01
Lx, Ly = scaling * Lx, scaling * Ly
np.random.seed(seed=1)
noise_std_dev = 0.3
noise = noise_std_dev * np.random.randn(data.shape[0], data.shape[1])
print '||noise||={}'.format(np.linalg.norm(noise))
mesh = dl.RectangleMesh(dl.Point(0, 0), dl.Point(Lx, Ly), 200, 100)
mcoord = mesh.coordinates()
print 'hx={}, hy={}'.format((mcoord[-1][0] - mcoord[0][0]) / 200.,
(mcoord[-1][1] - mcoord[0][1]) / 100.)
V = dl.FunctionSpace(mesh, 'Lagrange', CGdeg)
trueImage = Image(Lx, Ly, data)
noisyImage = Image(Lx, Ly, data + noise)
print 'min(data)={}, max(data)={}'.format(np.amin(data), np.amax(data))
print 'min(data+noise)={}, max(data+noise)={}'.format(
np.amin(data + noise), np.amax(data + noise))
self.u_true = dl.interpolate(trueImage, V)
self.u_0 = dl.interpolate(noisyImage, V)
self.u = dl.Function(V)
self.ucopy = dl.Function(V)
self.G = dl.Function(V)
self.du = dl.Function(V)
u_test = dl.TestFunction(V)
u_trial = dl.TrialFunction(V)
Mweak = dl.inner(u_test, u_trial) * dl.dx
self.M = dl.assemble(Mweak)
self.solverM = dl.LUSolver('petsc')
self.solverM.parameters['symmetric'] = True
self.solverM.parameters['reuse_factorization'] = True
self.solverM.set_operator(self.M)
self.regul = regularizationtype
if self.regul == 'tikhonov':
self.Regul = LaplacianPrior({'Vm': V, 'gamma': 1.0, 'beta': 0.0})
elif self.regul == 'TV':
paramTV = {'Vm': V, 'k': 1.0, 'eps': 1e-4, 'GNhessian': True}
paramTV.update(parameters)
self.Regul = TV(paramTV)
self.inexact = False
elif self.regul == 'TVPD':
paramTV = {'Vm': V, 'k': 1.0, 'eps': 1e-4, 'exact': False}
paramTV.update(parameters)
self.Regul = TVPD(paramTV)
self.inexact = False
self.alpha = 1.0
self.Hess = self.M
self.parametersLS = {'alpha0':1.0, 'rho':0.5, 'c':5e-5, \
'max_backtrack':12, 'cgtol':0.5, 'maxiter':50000}
filename, ext = os.path.splitext(sys.argv[0])
#if os.path.isdir(filename + '/'): shutil.rmtree(filename + '/')
self.myplot = PlotFenics(filename)
try:
solver = PETScKrylovSolver('cg', 'ml_amg')
self.precond = 'ml_amg'
except:
print '*** WARNING: ML not installed -- using petsc_amg instead'
self.precond = 'petsc_amg'
class ObjectiveFunctional(LinearOperator):
"""
Provides data misfit, gradient and Hessian information for the data misfit
part of a time-independent symmetric inverse problem.
"""
__metaclass__ = abc.ABCMeta
# Instantiation
def __init__(self, V, Vm, bc, bcadj, \
RHSinput=[], ObsOp=[], UD=[], Regul=[], Data=[], plot=False, \
mycomm=None):
# Define test, trial and all other functions
self.trial = TrialFunction(V)
self.test = TestFunction(V)
self.mtrial = TrialFunction(Vm)
self.mtest = TestFunction(Vm)
self.rhs = Function(V)
self.m = Function(Vm)
self.mcopy = Function(Vm)
self.srchdir = Function(Vm)
self.delta_m = Function(Vm)
self.MG = Function(Vm)
self.Grad = Function(Vm)
self.Gradnorm = 0.0
self.lenm = len(self.m.vector().array())
self.u = Function(V)
self.ud = Function(V)
self.diff = Function(V)
self.p = Function(V)
# Define weak forms to assemble A, C and E
self._wkforma()
self._wkformc()
self._wkforme()
# Store other info:
self.ObsOp = ObsOp
self.UD = UD
self.reset() # Initialize U, C and E to []
self.Data = Data
self.GN = 1.0 # GN = 0.0 => GN Hessian; = 1.0 => full Hessian
# Operators and bc
LinearOperator.__init__(self, self.delta_m.vector(), \
self.delta_m.vector())
self.bc = bc
self.bcadj = bcadj
self._assemble_solverM(Vm)
self.assemble_A()
self.assemble_RHS(RHSinput)
self.Regul = Regul
# Counters, tolerances and others
self.nbPDEsolves = 0 # Updated when solve_A called
self.nbfwdsolves = 0 # Counter for plots
self.nbadjsolves = 0 # Counter for plots
self._set_plots(plot)
# MPI:
self.mycomm = mycomm
try:
self.myrank = MPI.rank(self.mycomm)
except:
self.myrank = 0
def copy(self):
"""Define a copy method"""
V = self.trial.function_space()
Vm = self.mtrial.function_space()
newobj = self.__class__(V, Vm, self.bc, self.bcadj, [], self.ObsOp, \
self.UD, self.Regul, self.Data, False)
newobj.RHS = self.RHS
newobj.update_m(self.m)
return newobj
def mult(self, mhat, y):
"""mult(self, mhat, y): do y = Hessian * mhat
member self.GN sets full Hessian (=1.0) or GN Hessian (=0.0)"""
N = self.Nbsrc # Number of sources
y[:] = np.zeros(self.lenm)
for C, E in zip(self.C, self.E):
# Solve for uhat
C.transpmult(mhat, self.rhs.vector())
self.bcadj.apply(self.rhs.vector())
self.solve_A(self.u.vector(), -self.rhs.vector())
# Solve for phat
E.transpmult(mhat, self.rhs.vector())
Etmhat = self.rhs.vector().array()
self.rhs.vector().axpy(1.0, self.ObsOp.incradj(self.u))
self.bcadj.apply(self.rhs.vector())
self.solve_A(self.p.vector(), -self.rhs.vector())
# Compute Hessian*x:
y.axpy(1.0/N, C * self.p.vector())
y.axpy(self.GN/N, E * self.u.vector())
y.axpy(1.0, self.Regul.hessian(mhat))
# Getters
def getm(self): return self.m
def getmarray(self): return self.m.vector().array()
def getmcopyarray(self): return self.mcopy.vector().array()
def getVm(self): return self.mtrial.function_space()
def getMGarray(self): return self.MG.vector().array()
def getMGvec(self): return self.MG.vector()
def getGradarray(self): return self.Grad.vector().array()
def getGradnorm(self): return self.Gradnorm
def getsrchdirarray(self): return self.srchdir.vector().array()
def getsrchdirvec(self): return self.srchdir.vector()
def getsrchdirnorm(self):
return np.sqrt((self.MM*self.getsrchdirvec()).inner(self.getsrchdirvec()))
def getgradxdir(self): return self.gradxdir
def getcost(self): return self.cost, self.misfit, self.regul
def getprecond(self):
Prec = PETScKrylovSolver("richardson", "amg")
Prec.parameters["maximum_iterations"] = 1
Prec.parameters["error_on_nonconvergence"] = False
Prec.parameters["nonzero_initial_guess"] = False
Prec.set_operator(self.Regul.get_precond())
return Prec
def getMass(self): return self.MM
# Setters
def setsrchdir(self, arr): self.srchdir.vector()[:] = arr
def setgradxdir(self, valueloc):
"""Sum all local results for Grad . Srch_dir"""
try:
valueglob = MPI.sum(self.mycomm, valueloc)
except:
valueglob = valueloc
self.gradxdir = valueglob
# Solve
def solvefwd(self, cost=False):
"""Solve fwd operators for given RHS"""
self.nbfwdsolves += 1
if self.ObsOp.noise: self.noise = 0.0
if self.plot:
self.plotu = PlotFenics(self.plotoutdir)
self.plotu.set_varname('u{0}'.format(self.nbfwdsolves))
if cost: self.misfit = 0.0
for ii, rhs in enumerate(self.RHS):
self.solve_A(self.u.vector(), rhs)
if self.plot: self.plotu.plot_vtk(self.u, ii)
u_obs, noiselevel = self.ObsOp.obs(self.u)
self.U.append(u_obs)
if self.ObsOp.noise: self.noise += noiselevel
if cost:
self.misfit += self.ObsOp.costfct(u_obs, self.UD[ii])
self.C.append(assemble(self.c))
if cost:
self.misfit /= len(self.U)
self.regul = self.Regul.cost(self.m)
self.cost = self.misfit + self.regul
if self.ObsOp.noise and self.myrank == 0:
print 'Total noise in data misfit={:.5e}\n'.\
format(self.noise*.5/len(self.U))
self.ObsOp.noise = False # Safety
if self.plot: self.plotu.gather_vtkplots()
def solvefwd_cost(self):
"""Solve fwd operators for given RHS and compute cost fct"""
self.solvefwd(True)
def solveadj(self, grad=False):
"""Solve adj operators"""
self.nbadjsolves += 1
if self.plot:
self.plotp = PlotFenics(self.plotoutdir)
self.plotp.set_varname('p{0}'.format(self.nbadjsolves))
self.Nbsrc = len(self.UD)
if grad: self.MG.vector()[:] = np.zeros(self.lenm)
for ii, C in enumerate(self.C):
self.ObsOp.assemble_rhsadj(self.U[ii], self.UD[ii], \
self.rhs, self.bcadj)
self.solve_A(self.p.vector(), self.rhs.vector())
if self.plot: self.plotp.plot_vtk(self.p, ii)
self.E.append(assemble(self.e))
if grad: self.MG.vector().axpy(1.0/self.Nbsrc, \
C * self.p.vector())
if grad:
self.MG.vector().axpy(1.0, self.Regul.grad(self.m))
self.solverM.solve(self.Grad.vector(), self.MG.vector())
self.Gradnorm = np.sqrt(self.Grad.vector().inner(self.MG.vector()))
if self.plot: self.plotp.gather_vtkplots()
def solveadj_constructgrad(self):
"""Solve adj operators and assemble gradient"""
self.solveadj(True)
# Assembler
def assemble_A(self):
"""Assemble operator A(m)"""
self.A = assemble(self.a)
self.bc.apply(self.A)
self.set_solver()
def solve_A(self, b, f):
"""Solve system of the form A.b = f,
with b and f in form to be used in solver."""
self.solver.solve(b, f)
self.nbPDEsolves += 1
def assemble_RHS(self, RHSin):
"""Assemble RHS for fwd solve"""
if RHSin == []: self.RHS = None
else:
self.RHS = []
for rhs in RHSin:
if isinstance(rhs, Expression):
L = rhs*self.test*dx
b = assemble(L)
self.bc.apply(b)
self.RHS.append(b)
else: raise WrongInstanceError("rhs should be Expression")
def _assemble_solverM(self, Vm):
self.MM = assemble(inner(self.mtrial, self.mtest)*dx)
self.solverM = LUSolver()
self.solverM.parameters['reuse_factorization'] = True
self.solverM.parameters['symmetric'] = True
self.solverM.set_operator(self.MM)
def _set_plots(self, plot):
self.plot = plot
if self.plot:
filename, ext = splitext(sys.argv[0])
self.plotoutdir = filename + '/Plots/'
self.plotvarm = PlotFenics(self.plotoutdir)
self.plotvarm.set_varname('m')
def plotm(self, index):
if self.plot: self.plotvarm.plot_vtk(self.m, index)
def gatherm(self):
if self.plot: self.plotvarm.gather_vtkplots()
# Update param
def update_Data(self, Data):
"""Update Data member"""
self.Data = Data
self.assemble_A()
self.reset()
def update_m(self, m):
"""Update values of parameter m"""
if isinstance(m, np.ndarray):
self.m.vector()[:] = m
elif isinstance(m, Function):
self.m.assign(m)
elif isinstance(m, float):
self.m.vector()[:] = m
elif isinstance(m, int):
self.m.vector()[:] = float(m)
else: raise WrongInstanceError('Format for m not accepted')
self.assemble_A()
self.reset()
def backup_m(self):
self.mcopy.assign(self.m)
def restore_m(self):
self.update_m(self.mcopy)
def reset(self):
"""Reset U, C and E"""
self.U = []
self.C = []
self.E = []
def set_solver(self):
"""Reset solver for fwd operator"""
self.solver = LUSolver()
self.solver.parameters['reuse_factorization'] = True
self.solver.set_operator(self.A)
def addPDEcount(self, increment=1):
"""Increase 'nbPDEsolves' by 'increment'"""
self.nbPDEsolves += increment
def resetPDEsolves(self):
self.nbPDEsolves = 0
# Additional methods for compatibility with CG solver:
def init_vector(self, x, dim):
"""Initialize vector x to be compatible with parameter
Does not work in dolfin 1.3.0"""
self.MM.init_vector(x, 0)
def init_vector130(self):
"""Initialize vector x to be compatible with parameter"""
return Vector(Function(self.mcopy.function_space()).vector())
# Abstract methods
@abc.abstractmethod
def _wkforma(self): self.a = []
@abc.abstractmethod
def _wkformc(self): self.c = []
@abc.abstractmethod
def _wkforme(self): self.e = []
class ObjectiveImageDenoising():
def __init__(self,
CGdeg,
regularizationtype,
h=1.0,
parameters=[],
image='image.dat'):
class Image(dl.Expression):
def __init__(self, Lx, Ly, data):
self.data = data
self.hx = Lx / float(self.data.shape[1] - 1)
self.hy = Ly / float(self.data.shape[0] - 1)
def eval(self, values, x):
j = math.floor(x[0] / self.hx)
i = math.floor(x[1] / self.hy)
values[0] = self.data[i, j]
data = np.loadtxt(image, delimiter=',')
#Lx, Ly = float(data.shape[1])/float(data.shape[0]), 1.
Lx, Ly = 2., 1.
scaling = 100. * h # =1.0 => h~0.01
Lx, Ly = scaling * Lx, scaling * Ly
np.random.seed(seed=1)
noise_std_dev = 0.3
noise = noise_std_dev * np.random.randn(data.shape[0], data.shape[1])
print '||noise||={}'.format(np.linalg.norm(noise))
mesh = dl.RectangleMesh(dl.Point(0, 0), dl.Point(Lx, Ly), 200, 100)
mcoord = mesh.coordinates()
print 'hx={}, hy={}'.format((mcoord[-1][0] - mcoord[0][0]) / 200.,
(mcoord[-1][1] - mcoord[0][1]) / 100.)
V = dl.FunctionSpace(mesh, 'Lagrange', CGdeg)
trueImage = Image(Lx, Ly, data)
noisyImage = Image(Lx, Ly, data + noise)
print 'min(data)={}, max(data)={}'.format(np.amin(data), np.amax(data))
print 'min(data+noise)={}, max(data+noise)={}'.format(
np.amin(data + noise), np.amax(data + noise))
self.u_true = dl.interpolate(trueImage, V)
self.u_0 = dl.interpolate(noisyImage, V)
self.u = dl.Function(V)
self.ucopy = dl.Function(V)
self.G = dl.Function(V)
self.du = dl.Function(V)
u_test = dl.TestFunction(V)
u_trial = dl.TrialFunction(V)
Mweak = dl.inner(u_test, u_trial) * dl.dx
self.M = dl.assemble(Mweak)
self.solverM = dl.LUSolver('petsc')
self.solverM.parameters['symmetric'] = True
self.solverM.parameters['reuse_factorization'] = True
self.solverM.set_operator(self.M)
self.regul = regularizationtype
if self.regul == 'tikhonov':
self.Regul = LaplacianPrior({'Vm': V, 'gamma': 1.0, 'beta': 0.0})
elif self.regul == 'TV':
paramTV = {'Vm': V, 'k': 1.0, 'eps': 1e-4, 'GNhessian': True}
paramTV.update(parameters)
self.Regul = TV(paramTV)
self.inexact = False
elif self.regul == 'TVPD':
paramTV = {'Vm': V, 'k': 1.0, 'eps': 1e-4, 'exact': False}
paramTV.update(parameters)
self.Regul = TVPD(paramTV)
self.inexact = False
self.alpha = 1.0
self.Hess = self.M
self.parametersLS = {'alpha0':1.0, 'rho':0.5, 'c':5e-5, \
'max_backtrack':12, 'cgtol':0.5, 'maxiter':50000}
filename, ext = os.path.splitext(sys.argv[0])
#if os.path.isdir(filename + '/'): shutil.rmtree(filename + '/')
self.myplot = PlotFenics(filename)
try:
solver = PETScKrylovSolver('cg', 'ml_amg')
self.precond = 'ml_amg'
except:
print '*** WARNING: ML not installed -- using petsc_amg instead'
self.precond = 'petsc_amg'
def solve(self):
if self.regul == 'tikhonov': self.solvetikhonov()
elif self.regul == 'TV': self.solveTV()
elif self.regul == 'TVPD': self.solveTV()
def costmisfitreg(self):
""" Compute objective function (cost = misfit + alpha*reg) """
misfit = 0.5*(self.Hess*(self.u.vector() - self.u_0.vector())).inner(\
self.u.vector() - self.u_0.vector())
reg = self.Regul.cost(self.u)
cost = misfit + self.alpha * reg
return cost, misfit, reg
def gradient(self):
""" Compute gradient at current value of self.u """
MG = self.Hess * (self.u.vector() - self.u_0.vector())
MG.axpy(self.alpha, self.Regul.grad(self.u))
self.solverM.solve(self.G.vector(), MG)
return MG, np.sqrt(MG.inner(self.G.vector()))
def mediummisfit(self):
""" Compute medium misfit """
return np.sqrt((self.Hess*(self.u.vector() - self.u_true.vector())).inner(\
self.u.vector() - self.u_true.vector()))
def solvetikhonov(self):
print '\t{:12s} {:12s} {:12s} {:12s} {:12s} {:12s}'.format(\
'iter', 'cost', 'misfit', 'reg', 'medmisfit', 'n_cg')
self.u.vector().zero()
MG, MGnorm = self.gradient()
H = self.Hess + self.Regul.R * self.alpha
solver = dl.PETScKrylovSolver("cg", "petsc_amg")
solver.set_operator(H)
cgiter = solver.solve(self.u.vector(), -MG)
cost, misfit, reg = self.costmisfitreg()
print '{:12s} {:12.4e} {:12.4e} {:12.4e} {:12.4e} {:12d}'.format(\
'', cost, misfit, reg, self.mediummisfit(), cgiter)
def searchdirection(self, MG, cgtol):
""" Compute search direction """
self.Regul.assemble_hessian(self.u)
if self.Regul.isPD():
H = self.Hess + self.Regul.Hrs * self.alpha
#H = self.Hess + self.Regul.H*self.alpha
else:
H = self.Hess + self.Regul.H * self.alpha
if True:
solver = dl.PETScKrylovSolver("cg", self.precond)
solver.parameters['nonzero_initial_guess'] = False
solver.parameters['relative_tolerance'] = cgtol
solver.set_operator(H)
cgiter = solver.solve(self.du.vector(), -1.0 * MG)
else:
solver = CGSolverSteihaug()
solver.set_operator(H)
solver.set_preconditioner(self.Regul.getprecond())
solver.parameters["rel_tolerance"] = cgtol
solver.parameters["zero_initial_guess"] = True
solver.parameters["print_level"] = -1
solver.solve(self.du.vector(), -1.0 * MG)
cgiter = solver.iter
MGdu = MG.inner(self.du.vector())
if MGdu > 0.0:
print "*** WARNING: NOT a descent direction"
return cgiter, MGdu
def linesearch(self, MG):
""" Perform inexact backtracking line search """
alphaLS = self.parametersLS['alpha0']
rhoLS = self.parametersLS['rho']
cLS = self.parametersLS['c']
cost, misfit, reg = self.costmisfitreg()
costref = cost
setfct(self.ucopy, self.u)
MGdu = MG.inner(self.du.vector()) * cLS
success = False
for ii in xrange(self.parametersLS['max_backtrack']):
setfct(self.u, self.ucopy)
self.u.vector().axpy(alphaLS, self.du.vector())
cost, misfit, reg = self.costmisfitreg()
if cost < costref + alphaLS * MGdu:
success = True
break
else:
alphaLS *= rhoLS
if self.Regul.isPD(): self.Regul.update_w(self.du.vector(), alphaLS)
return success, alphaLS, cost, misfit, reg
def solveTV(self):
""" Solve image denoising pb """
self.u.vector().zero()
normu_true = self.mediummisfit()
# initial state = noisy image
setfct(self.u, self.u_0)
print 'min(u)={}, max(u)={}'.format(\
np.amin(self.u.vector().array()), np.amax(self.u.vector().array()))
cost, misfit, reg = self.costmisfitreg()
costold = cost
MG, normMG = self.gradient()
normMG0 = normMG
print '\t{:12s} {:12s} {:12s} {:12s} {:12s} {:12s} {:12s}\t{:12s} {:12s}'.format(\
'iter', 'cost', 'misfit', 'reg', '||G||', 'a_LS', 'medmisfit', 'tol_cg', 'n_cg')
print '{:12d} {:12.4e} {:12.4e} {:12.4e} {:12.4e} {:12s} {:12.2e} ({:7.2f} %)'.format(\
0, cost, misfit, reg, normMG, '', self.mediummisfit(), 100.*self.mediummisfit()/normu_true)
cgtol = self.parametersLS['cgtol']
maxiter = self.parametersLS['maxiter']
for ii in xrange(maxiter):
if self.inexact:
cgtol = min(cgtol, np.sqrt(normMG / normMG0))
#cgtol = min(0.5, np.sqrt(normMG/normMG0)))
else:
cgtol = 1e-12
cgiter, MGdu = self.searchdirection(MG, cgtol)
success, alphaLS, cost, misfit, reg = self.linesearch(MG)
MG, normMG = self.gradient()
print '{:12d} {:12.4e} {:12.4e} {:12.4e} {:12.4e} {:12.4e} {:12.2e} ({:7.2f} %) {:12.2e} {:12d}'.format(\
ii+1, cost, misfit, reg, normMG, alphaLS, \
self.mediummisfit(), 100.*self.mediummisfit()/normu_true, cgtol, cgiter)
if normMG < min(1e-12, 1e-10 * normMG0):
print 'gradient sufficiently reduced -- optimization converged'
break
if not success:
print 'Line search failed -- optimization aborted'
break
if np.abs(cost - costold) / costold < 1e-14:
if cgtol < 1e-10:
print 'cost functional stagnates -- optimization aborted'
break
else:
cgtol *= 1e-3
costold = cost
print 'min(u)={}, max(u)={}'.format(\
np.amin(self.u.vector().array()), np.amax(self.u.vector().array()))
def plot(self, index=0, add=''):
""" Plot target (w/ noise 0, or w/o noise 1) or current iterate (2) """
if index == 0:
self.myplot.set_varname('data' + add)
self.myplot.plot_vtk(self.u_0)
elif index == 1:
self.myplot.set_varname('target' + add)
self.myplot.plot_vtk(self.u_true)
elif index == 2:
self.myplot.set_varname('solution' + add)
self.myplot.plot_vtk(self.u)
class ObjectiveImageDenoising:
"""
Class to do image denoising
"""
def __init__(self, mesh, trueImage, parameters=[]):
"""
Inputs:
mesh = Fenics mesh
trueImage = object from class Image
parameters = dict
"""
# Mesh
self.mesh = mesh
self.V = dl.FunctionSpace(self.mesh, "Lagrange", 1)
self.xx = self.V.dofmap().tabulate_all_coordinates(self.mesh)
self.dimV = self.V.dim()
self.test, self.trial = dl.TestFunction(self.V), dl.TrialFunction(self.V)
self.f_true = dl.interpolate(trueImage, self.V)
self.g, self.dg, self.gtmp = dl.Function(self.V), dl.Function(self.V), dl.Function(self.V)
self.Grad = dl.Function(self.V)
self.Gradnorm0 = None
# mass matrix
self.Mweak = dl.inner(self.test, self.trial) * dl.dx
self.M = dl.assemble(self.Mweak)
self.solverM = dl.LUSolver("petsc")
self.solverM.parameters["symmetric"] = True
self.solverM.parameters["reuse_factorization"] = True
self.solverM.set_operator(self.M)
# identity matrix
self.I = dl.assemble(self.Mweak)
self.I.zero()
self.I.set_diagonal(dl.interpolate(dl.Constant(1), self.V).vector())
# self.targetnorm = np.sqrt((self.M*self.f_true.vector()).inner(self.f_true.vector()))
self.targetnorm = np.sqrt((self.f_true.vector()).inner(self.f_true.vector()))
# line search parameters
self.parameters = {"alpha0": 1.0, "rho": 0.5, "c": 5e-5, "max_backtrack": 12}
# regularization
self.parameters.update({"eps": 1e-4, "k": 1.0, "regularization": "TV", "mode": "primaldual"})
self.parameters.update(parameters)
self.define_regularization()
self.regparam = 1.0
# plots:
filename, ext = os.path.splitext(sys.argv[0])
if os.path.isdir(filename + "/"):
shutil.rmtree(filename + "/")
self.myplot = PlotFenics(filename)
def generatedata(self, noisepercent):
""" compute data and add noisepercent (%) of noise """
sigma = noisepercent * np.linalg.norm(self.f_true.vector().array()) / np.sqrt(self.dimV)
print "sigma_noise = ", sigma
np.random.seed(11) # TODO: tmp
eta = sigma * np.random.randn(self.dimV)
self.dn = dl.Function(self.V)
setfct(self.dn, eta)
self.dn.vector().axpy(1.0, self.f_true.vector())
print "min(true)={}, max(true)={}".format(
np.amin(self.f_true.vector().array()), np.amax(self.f_true.vector().array())
)
print "min(noisy)={}, max(noisy)={}".format(
np.amin(self.dn.vector().array()), np.amax(self.dn.vector().array())
)
def define_regularization(self, parameters=None):
if not parameters == None:
self.parameters.update(parameters)
regularization = self.parameters["regularization"]
if regularization == "tikhonov":
gamma = self.parameters["gamma"]
beta = self.parameters["beta"]
self.Reg = LaplacianPrior({"gamma": gamma, "beta": beta, "Vm": self.V})
self.inexact = False
elif regularization == "TV":
eps = self.parameters["eps"]
k = self.parameters["k"]
mode = self.parameters["mode"]
if mode == "primaldual":
self.Reg = self.Reg = TVPD({"eps": eps, "k": k, "Vm": self.V, "GNhessian": False})
elif mode == "full":
self.Reg = TV({"eps": eps, "k": k, "Vm": self.V, "GNhessian": False})
else:
self.Reg = TV({"eps": eps, "k": k, "Vm": self.V, "GNhessian": True})
self.inexact = False
### COST and DERIVATIVES
def computecost(self, f=None):
""" Compute cost functional at f """
if f == None:
f = self.g
df = f.vector() - self.dn.vector()
# self.misfit = 0.5 * (self.M*df).inner(df)
self.misfit = 0.5 * df.inner(df)
self.reg = self.Reg.cost(f)
self.cost = self.misfit + self.regparam * self.reg
return self.cost
def gradient(self, f=None):
""" Compute M.g (discrete gradient) at a given point f """
if f == None:
f = self.g
df = f.vector() - self.dn.vector()
# self.MGk = self.M*df
self.MGk = df
self.MGr = self.Reg.grad(f)
self.MG = self.MGk + self.MGr * self.regparam
self.solverM.solve(self.Grad.vector(), self.MG)
self.Gradnorm = np.sqrt((self.MG).inner(self.Grad.vector()))
if self.Gradnorm0 == None:
self.Gradnorm0 = self.Gradnorm
def Hessian(self, f=None):
""" Assemble Hessian at f """
if f == None:
f = self.g
regularization = self.parameters["regularization"]
if regularization == "TV":
self.Reg.assemble_hessian(f)
self.Hess = self.I + self.Reg.H * self.regparam
# self.Hess = self.M + self.Reg.H*self.regparam
elif regularization == "tikhonov":
self.Hess = self.M + self.Reg.Minvprior * self.regparam
### SOLVER
def searchdirection(self):
""" Compute search direction """
self.gradient()
self.Hessian()
solver = dl.PETScKrylovSolver("cg", "petsc_amg")
solver.parameters["nonzero_initial_guess"] = False
# Inexact CG:
if self.inexact:
self.cgtol = min(0.5, np.sqrt(self.Gradnorm / self.Gradnorm0))
else:
self.cgtol = 1e-8
solver.parameters["relative_tolerance"] = self.cgtol
solver.set_operator(self.Hess)
self.cgiter = solver.solve(self.dg.vector(), -1.0 * self.MG)
if (self.MG).inner(self.dg.vector()) > 0.0:
print "*** WARNING: NOT a descent direction"
def linesearch(self):
""" Perform inexact backtracking line search """
regularization = self.parameters["regularization"]
# compute new direction for dual variables
if regularization == "TV" and self.Reg.isPD():
self.Reg.compute_dw(self.dg)
# line search for primal variable
self.alpha = self.parameters["alpha0"]
rho = self.parameters["rho"]
c = self.parameters["c"]
self.computecost()
costref = self.cost
cdJdf = ((self.MG).inner(self.dg.vector())) * c
self.LS = False
for ii in xrange(self.parameters["max_backtrack"]):
setfct(self.gtmp, self.g.vector() + self.dg.vector() * self.alpha)
if self.computecost(self.gtmp) < costref + self.alpha * cdJdf:
self.g.vector().axpy(self.alpha, self.dg.vector())
self.LS = True
break
else:
self.alpha *= rho
# update dual variable
if regularization == "TV" and self.Reg.isPD():
self.Reg.update_w(self.alpha)
def solve(self, plot=False):
""" Solve image denoising pb """
regularization = self.parameters["regularization"]
print "\t{:12s} {:12s} {:12s} {:12s} {:12s} {:12s} {:12s}\t{:12s} {:12s}".format(
"a_reg", "cost", "misfit", "reg", "||G||", "a_LS", "medmisfit", "tol_cg", "n_cg"
)
#
if regularization == "tikhonov":
# pb is linear with tikhonov regularization
self.searchdirection()
self.g.vector().axpy(1.0, self.dg.vector())
self.computecost()
self.alpha = 1.0
self.printout()
else:
self.computecost()
cost = self.cost
# initial printout
df = self.f_true.vector() - self.g.vector()
self.medmisfit = np.sqrt(df.inner(df))
# self.medmisfit = np.sqrt((self.M*df).inner(df))
self.relmedmisfit = self.medmisfit / self.targetnorm
print ("{:12.1e} {:12.4e} {:12.4e} {:12.4e} {:12s} {:12s} {:12.2e}" + " ({:.3f})").format(
self.regparam, self.cost, self.misfit, self.reg, "", "", self.medmisfit ** 2, self.relmedmisfit
)
# iterate
for ii in xrange(1000):
self.searchdirection()
self.linesearch()
print ii + 1,
self.printout()
# Check termination conditions:
if not self.LS:
print "Line search failed"
break
if self.Gradnorm < min(1e-12, 1e-10 * self.Gradnorm0):
print "gradient sufficiently reduced -- optimization converged"
break
elif np.abs(cost - self.cost) / cost < 1e-12:
print "cost functional stagnates -- optimization converged"
break
cost = self.cost
### OUTPUT
def printout(self):
""" Print results """
df = self.f_true.vector() - self.g.vector()
self.medmisfit = np.sqrt((self.M * df).inner(df))
self.relmedmisfit = self.medmisfit / self.targetnorm
print ("{:12.1e} {:12.4e} {:12.4e} {:12.4e} {:12.4e} {:12.2e} {:12.2e}" + " ({:.3f}) {:12.2e} {:6d}").format(
self.regparam,
self.cost,
self.misfit,
self.reg,
self.Gradnorm,
self.alpha,
self.medmisfit ** 2,
self.relmedmisfit,
self.cgtol,
self.cgiter,
)
def plot(self, index=0, add=""):
""" Plot target (w/ noise 0, or w/o noise 1) or current iterate (2) """
if index == 0:
self.myplot.set_varname("target" + add)
self.myplot.plot_vtk(self.f_true)
elif index == 1:
self.myplot.set_varname("data" + add)
self.myplot.plot_vtk(self.dn)
elif index == 2:
self.myplot.set_varname("solution" + add)
self.myplot.plot_vtk(self.g)
### TESTS
def test_gradient(self, f=None, n=5):
""" test gradient with FD approx around point f """
if f == None:
f = self.f_true
pm = [1.0, -1.0]
eps = 1e-5
self.gradient(f)
for nn in xrange(1, n + 1):
expr = dl.Expression("sin(n*pi*x[0]/200)*sin(n*pi*x[1]/100)", n=nn)
df = dl.interpolate(expr, self.V)
MGdf = self.MG.inner(df.vector())
cost = []
for sign in pm:
setfct(self.g, f)
self.g.vector().axpy(sign * eps, df.vector())
cost.append(self.computecost(self.g))
MGFD = (cost[0] - cost[1]) / (2 * eps)
print "n={}:\tMGFD={:.5e}, MGdf={:.5e}, error={:.2e}".format(
nn, MGFD, MGdf, np.abs(MGdf - MGFD) / np.abs(MGdf)
)
def test_hessian(self, f=None, n=5):
""" test Hessian with FD approx around point f """
if f == None:
f = self.f_true
pm = [1.0, -1.0]
eps = 1e-5
self.Hessian(f)
for nn in xrange(1, n + 1):
expr = dl.Expression("sin(n*pi*x[0]/200)*sin(n*pi*x[1]/100)", n=nn)
df = dl.interpolate(expr, self.V)
Hdf = (self.Hess * df.vector()).array()
MG = []
for sign in pm:
setfct(self.g, f)
self.g.vector().axpy(sign * eps, df.vector())
self.gradient(self.g)
MG.append(self.MG.array())
HFD = (MG[0] - MG[1]) / (2 * eps)
print "n={}:\tHFD={:.5e}, Hdf={:.5e}, error={:.2e}".format(
nn, np.linalg.norm(HFD), np.linalg.norm(Hdf), np.linalg.norm(Hdf - HFD) / np.linalg.norm(Hdf)
)