文件
gprMax/user_libs/DebyeFit/Debye_Fit.py
2021-07-06 12:01:21 +02:00

675 行
30 KiB
Python

# Author: Iraklis Giannakis, Sylwia Majchrowska
# E-mail: i.giannakis@ed.ac.uk
#
# Copyright (c) 2021 gprMax
# All rights reserved.
#
# Redistribution and use in source and binary forms are permitted
# provided that the above copyright notice and this paragraph are
# duplicated in all such forms and that any documentation,
# advertising materials, and other materials related to such
# distribution and use acknowledge that the software was developed
# as part of gprMax. The name of gprMax may not be used to
# endorse or promote products derived from this software without
# specific prior written permission.
# THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
import numpy as np
import os
from matplotlib import pylab as plt
import sys
import scipy.interpolate
from optimization import *
class Relaxation(object):
def __init__(self, number_of_debye_poles,
sigma, mu, mu_sigma,
material_name, plot=True, save=True,
optimizer=Particle_swarm,
optimizer_options={}):
"""
Create Relaxation function object for complex material.
Args:
number_of_debye_poles (int): Number of Debye functions used to
approximate the given electric
permittivity.
sigma (float): Conductivity.
mu (float): Relative permabillity.
mu_sigma (float): Magnetic looses.
material_name (str): A string containing the given name of
the material (e.g. "Clay").
plot (bool): if True will plot the actual and the approximated
permittivity (it can be neglected).
The argument is optional and if neglected plot=False.
save (bool): if True will save approximated material parameters
The argument is optional and if neglected save=False.
optimizer (Optimizer class): chosen optimization method:
Particle Swarm, Genetic or Dual Annealing.
optimizer_options (dict): Additional keyword arguments passed to
optimizer class (Default: empty dict).
"""
self.number_of_debye_poles = number_of_debye_poles
self.sigma = sigma
self.mu = mu
self.mu_sigma = mu_sigma
self.material_name = material_name
self.plot = plot
self.save = save
self.optimizer = optimizer(**optimizer_options)
def run(self):
"""
Solve the problem described by the given relaxation function
(Havriliak-Negami function, Crim, Jonscher)
or data given from a text file.
"""
# Check the validity of the inputs
self.check_inputs()
# Print information about chosen approximation settings
self.print_info()
# Calculate both real and imaginary parts
# for the frequencies included in the vector freq
q = self.calculation()
# Set the real and the imaginary part of the relaxation function
self.rl, self.im = q.real, q.imag
# Calling the main optimisation module
# if one of the weights is negative increase the stabiliser
# and repeat the optimisation
xmp, mx, ee, rp, ip = self.optimize()
# Print the results in gprMax format style
properties = self.print_output(xmp, mx, ee)
if self.save:
self.save_result(properties)
# Plot the actual and the approximate dielectric properties
if self.plot:
self.plot_result(rp + ee, ip)
def set_freq(self, f_min, f_max, n=50):
"""
Interpolate frequency vector using n
equally logarithmicaly spaced frequencies.
Args:
f_min (float): First bound of the frequency range
used to approximate the given function (Hz).
f_max (float): Second bound of the frequency range
used to approximate the given function (Hz).
n (int): Number of frequency points in frequency grid.
Note:
f_min and f_max must satisfied f_min < f_max
"""
# diff_freq = np.log10(f_max) - np.log10(f_min)
self.freq = np.logspace(np.log10(f_min) + 0.00001,
np.log10(f_max) - 0.00001,
int(n))
# int(n * diff_freq))
def check_inputs(self):
"""
Check the validity of the inputs.
"""
try:
d = [float(i) for i in
[self.number_of_debye_poles,
self.sigma, self.mu, self.mu_sigma]]
except ValueError:
sys.exit("The inputs should be numeric.")
if not isinstance(self.number_of_debye_poles, int):
sys.exit("The number of Debye poles must be integer.")
if (np.array(d) < 0).sum() != 0:
sys.exit("The inputs should be positive.")
def calculation(self):
"""
Approximate the given relaxation function
(Havriliak-Negami function, Crim, Jonscher) or based on raw data.
"""
raise NotImplementedError()
def print_info(self):
"""
Print information about chosen approximation settings.
"""
raise NotImplementedError()
def optimize(self):
"""
Calling the main optimisation module.
Returns:
xpm (array): The best known position form optimization module
(optimal design).
mx (array): Resulting optimised weights for the given relaxation times
ee (float): Average error between the actual and the approximated real part
rp (matrix): The real part of the permittivity for the optimised relaxation
times and weights for the frequnecies included in freq
ip (matrix): The imaginary part of the permittivity for the optimised
relaxation times and weights for the frequnecies included in freq
"""
# Define the lower and upper boundaries of search
lb = np.full(self.number_of_debye_poles,
-np.log10(np.max(self.freq)) - 3)
ub = np.full(self.number_of_debye_poles,
-np.log10(np.min(self.freq)) + 3)
# Call particle swarm optimisation to minimize the cost function.
xmp, _ = self.optimizer.fit(func=cost_function,
lb=lb, ub=ub,
funckwargs={'rl_g': self.rl,
'im_g': self.im,
'freq_g': self.freq}
)
_, _, mx, ee, rp, ip = linear(self.rl, self.im, xmp, self.freq)
return xmp, mx, ee, rp, ip
def print_output(self, xmp, mx, ee):
"""
Print out the resulting Debye parameters in a gprMax format.
Args:
xpm (array): The best known position form optimization module
(optimal design).
mx (): Resulting optimised weights for the given relaxation times.
ee (): Average error between the actual and the approximated real part.
"""
print("Debye expansion parameters: ")
print(f" |{'e_inf':^14s}|{'De':^14s}|{'log(t0)':^25s}|")
print("_" * 65)
for i in range(0, len(xmp)):
print("Debye {0:}:|{1:^14.5f}|{2:^14.5f}|{3:^25.5f}|"
.format(i + 1, ee/len(xmp), mx[i],
xmp[i]))
print("_" * 65)
# Print the Debye expnasion in a gprMax format
material_prop = "#material: {} {} {} {} {}".format(ee, self.sigma,
self.mu,
self.mu_sigma,
self.material_name)
print(material_prop)
material_prop = [material_prop + '\n']
dispersion_prop = "#add_dispersion_debye: {} {} {}".format(len(xmp),
mx[0],
10**xmp[0])
for i in range(1, len(xmp)):
dispersion_prop += " {} {}".format(mx[i], 10**xmp[i])
dispersion_prop += " {}".format(self.material_name)
print(dispersion_prop)
material_prop.append(dispersion_prop + '\n')
return material_prop
def plot_result(self, rl_exp, im_exp):
"""
Plot the actual and the approximated electric permittivity
using a semilogarithm X axes.
Args:
rl_exp (array): Real parts of optimised Debye expansion
for given frequency points (plus average error).
im_exp (array): Imaginary parts of optimised Debye expansion
for given frequency points.
"""
plt.close("all")
plt.rcParams["axes.facecolor"] = "black"
plt.semilogx(self.freq * 1e-6, rl_exp, "b-", linewidth=2.0,
label="Debye Expansion: Real")
plt.semilogx(self.freq * 1e-6, -im_exp, "w-", linewidth=2.0,
label="Debye Expansion: Imaginary")
plt.semilogx(self.freq * 1e-6, self.rl, "ro",
linewidth=2.0, label="Chosen Function: Real")
plt.semilogx(self.freq * 1e-6, -self.im, "go", linewidth=2.0,
label="Chosen Function: Imaginary")
plt.rcParams["axes.facecolor"] = "white"
plt.grid(b=True, which="major", color="w", linewidth=0.2,
linestyle="--")
axes = plt.gca()
axes.set_xlim([np.min(self.freq * 1e-6), np.max(self.freq * 1e-6)])
axes.set_ylim([-1, np.max(np.concatenate([self.rl, -self.im])) + 1])
plt.legend()
plt.xlabel("Frequency (MHz)")
plt.ylabel("Relative permittivity")
plt.show()
@staticmethod
def save_result(output, fdir="../materials"):
"""
Save the resulting Debye parameters in a gprMax format
Args:
output (str): Material and resulting Debye parameters
in a gprMax format.
fdir (str): Path to saving directory.
"""
if fdir != "../materials" and os.path.isdir(fdir):
file_path = os.path.join(fdir, "my_materials.txt")
elif os.path.isdir("../materials"):
file_path = os.path.join("../materials",
"my_materials.txt")
elif os.path.isdir("materials"):
file_path = os.path.join("materials",
"my_materials.txt")
elif os.path.isdir("user_libs/materials"):
file_path = os.path.join("user_libs", "materials",
"my_materials.txt")
else:
sys.exit("Cannot save material properties "
f"in {os.path.join(fdir, 'my_materials.txt')}!")
fileH = open(file_path, "a")
fileH.write(f"## {output[0].split(' ')[-1]}")
fileH.writelines(output)
fileH.write("\n")
fileH.close()
print(f"Material properties save at: {file_path}")
class HavriliakNegami(Relaxation):
def __init__(self, number_of_debye_poles,
f_min, f_max, alfa, bita, einf, de, t0,
sigma, mu, mu_sigma,
material_name, plot=False, save=True,
optimizer=Particle_swarm,
optimizer_options={}):
"""
Approximate a given Havriliak-Negami function
Havriliak-Negami function = einf + de / (1 + (1j * 2 * pi * f *t0)**alfa )**bita,
where f is the frequency in Hz
Args:
number_of_debye_poles (int): Number of Debye functions used to
approximate the given electric
permittivity.
f_min (float): Define the first bound of the frequency range
used to approximate the given function (Hz).
f_max (float): Define the second bound of the frequency range
used to approximate the given function (Hz).
Note: f_min and f_max can be either f_min > f_max
or f_min < f_max but not f_min = f_max.
einf (float): The real relative permittivity at infinity frequency
alfa (float): Havriliak-Negami parameter. Real positive float number
which varies 0 < alfa < 1. For alfa = 1 and bita !=0 & bita !=1
Havriliak-Negami transforms to Cole-Davidson function.
bita (float): Havriliak-Negami parameter. Real positive float number
which varies 0 < bita < 1. For bita = 1 and alfa !=0 & alfa !=1
Havriliak-Negami transforms to Cole-Cole function.
de (float): Havriliak-Negami parameter. Real positive float number.
de is the relative permittivity at infinite frequency
minus the relative permittivity at zero frequency.
t0 (float): Havriliak_Negami parameter. Real positive float number.
t0 is the relaxation time.
sigma (float): Conductivity.
mu (float): Relative permabillity.
mu_sigma (float): Magnetic looses.
material_name (str): A string containing the given name of
the material (e.g. "Clay").
plot (bool): if True will plot the actual and the approximated
permittivity. The argument is optional and
if neglected plot=False.
save (bool): if True will save approximated material parameters
The argument is optional and if neglected save=False.
optimizer (Optimizer class): chosen optimization method:
Particle Swarm, Genetic or Dual Annealing.
(Default: Partocle_swarm)
optimizer_options (dict): Additional keyword arguments passed to
optimizer class (Default: empty dict).
"""
super(HavriliakNegami, self).__init__(number_of_debye_poles,
sigma, mu, mu_sigma,
material_name, plot, save,
optimizer, optimizer_options)
# Place the lower frequency bound at f_min and the upper frequency bound at f_max
if f_min > f_max:
self.f_min, self.f_max = f_max, f_min
else:
self.f_min, self.f_max = f_min, f_max
# Choosing n frequencies logarithmicaly equally spaced between the bounds given
self.set_freq(self.f_min, self.f_max)
self.einf, self.alfa, self.bita, self.de, self.t0 = einf, alfa, bita, de, t0
def check_inputs(self):
"""
Check the validity of the inputs.
"""
super(HavriliakNegami, self).check_inputs()
try:
d = [float(i) for i in
[self.f_min, self.f_max, self.alfa,
self.bita, self.einf, self.de, self.t0]]
except ValueError:
sys.exit("The inputs should be numeric.")
if (np.array(d) < 0).sum() != 0:
sys.exit("The inputs should be positive.")
if self.alfa > 1:
sys.exit("Alfa value must range between 0-1 (0 <= Alfa <= 1)")
if self.bita > 1:
sys.exit("Beta value must range between 0-1 (0 <= Beta <= 1)")
if self.f_min == self.f_max:
sys.exit("Null frequency range")
def print_info(self):
"""Print information about chosen approximation settings."""
print(f"Approximating Havriliak-Negami function"
f" using {self.number_of_debye_poles} Debye poles")
print("Havriliak-Negami parameters : ")
print("De = {} \ne_inf = {} \nt0 = {} \nalfa = {} \nbita = {} "
.format(self.de, self.einf, self.t0, self.alfa, self.bita))
def calculation(self):
"""Calculates the Havriliak-Negami function for
the given parameters."""
return self.einf + self.de / (np.array(
1 + np.array(1j * 2 * np.pi *
self.freq * self.t0
) ** self.alfa)**self.bita)
class Jonscher(Relaxation):
def __init__(self, number_of_debye_poles,
f_min, f_max, einf, ap, omegap, n_p,
sigma, mu, mu_sigma,
material_name, plot=False, save=True,
optimizer=Particle_swarm,
optimizer_options={}):
"""
Approximate a given Johnsher function
Jonscher function = einf - ap * ( -1j * 2 * pi * f / omegap)**n_p,
where f is the frequency in Hz
Args:
number_of_debye_poles (int): Number of Debye functions used to
approximate the given electric
permittivity.
f_min (float): Define the first bound of the frequency range
used to approximate the given function (Hz).
f_max (float): Define the second bound of the frequency range
used to approximate the given function (Hz).
f_min and f_max can be either f_min > f_max
or f_min < f_max but not f_min = f_max.
einf (float): The real relative permittivity at infinity frequency
ap (float): Jonscher parameter. Real positive float number.
omegap (float): Jonscher parameter. Real positive float number.
n_p (float): Jonscher parameter.
Real positive float number which varies 0 < n_p < 1.
sigma (float): Conductivity.
mu (float): Relative permabillity.
mu_sigma (float): Magnetic looses.
material_name (str): A string containing the given name of
the material (e.g. "Clay").
plot (bool): if True will plot the actual and the approximated
permittivity. The argument is optional and
if neglected plot=False.
save (bool): if True will save approximated material parameters
The argument is optional and if neglected save=False.
optimizer (Optimizer class): chosen optimization method:
Particle Swarm, Genetic or Dual Annealing.
optimizer_options (dict): Additional keyword arguments passed to
optimizer class (Default: empty dict).
"""
super(Jonscher, self).__init__(number_of_debye_poles,
sigma, mu, mu_sigma,
material_name, plot, save,
optimizer, optimizer_options)
# Place the lower frequency bound at f_min and the upper frequency bound at f_max
if f_min > f_max:
self.f_min, self.f_max = f_max, f_min
else:
self.f_min, self.f_max = f_min, f_max
# Choosing n frequencies logarithmicaly equally spaced between the bounds given
self.set_freq(self.f_min, self.f_max)
self.einf, self.ap, self.omegap, self.n_p = einf, ap, omegap, n_p
def check_inputs(self):
"""
Check the validity of the inputs.
"""
super(Jonscher, self).check_inputs()
try:
d = [float(i) for i in
[self.f_min, self.f_max, self.n_p,
self.einf, self.omegap, self.ap]]
except ValueError:
sys.exit("The inputs should be numeric.")
if (np.array(d) < 0).sum() != 0:
sys.exit("The inputs should be positive.")
if self.n_p > 1:
sys.exit("n_p value must range between 0-1 (0 <= n_p <= 1)")
if self.f_min == self.f_max:
sys.exit("Error: Null frequency range")
def print_info(self):
"""
Print information about chosen approximation settings
"""
print(f"Approximating Jonsher function"
f" using {self.number_of_debye_poles} Debye poles")
print("Jonhser function parameters : ")
print(f"omega_p = {self.omegap}\n"
f"e_inf = {self.einf}\n"
f"n_p = {self.n_p}\n"
f"A_p = {self.ap}")
def calculation(self):
"""Calculates the Q function for the given parameters"""
return self.einf + (self.ap * np.array(
2 * np.pi * self.freq / self.omegap
)**(self.n_p-1)) * (
1 - 1j / np.tan(self.n_p * np.pi/2))
class Crim(Relaxation):
def __init__(self, number_of_debye_poles,
f_min, f_max, a, f1, e1, sigma,
mu, mu_sigma, material_name, plot=False, save=True,
optimizer=Particle_swarm,
optimizer_options={}):
"""
Approximate a given CRIM function
CRIM = (sum([volumetric_fraction[i]*(material[i][0] + material[i][1] /
(1 + (1j * 2 * pi * f *material[i][2])))**m_param
for i in range(0,len(material))]))**1/m_param
Args:
number_of_debye_poles (int): Number of Debye functions used to
approximate the given electric
permittivity.
f_min (float): Define the first bound of the frequency range
used to approximate the given function (Hz).
f_max (float): Define the second bound of the frequency range
used to approximate the given function (Hz).
f_min and f_max can be either f_min > f_max
or f_min < f_max but not f_min = f_max.
a (float): shape factor
f1 (list): volumetric fraction
e1 (list): materials
sigma (float): Conductivity.
mu (float): Relative permabillity.
mu_sigma (float): Magnetic looses.
material_name (str): A string containing the given name of
the material (e.g. "Clay").
plot (bool): if True will plot the actual and the approximated
permittivity. The argument is optional and
if neglected plot=False.
save (bool): if True will save approximated material parameters
The argument is optional and if neglected save=False.
optimizer (Optimizer class): chosen optimization method:
Particle Swarm, Genetic or Dual Annealing.
optimizer_options (dict): Additional keyword arguments passed to
optimizer class (Default: empty dict).
"""
super(Crim, self).__init__(number_of_debye_poles,
sigma, mu, mu_sigma,
material_name, plot, save,
optimizer, optimizer_options)
# Place the lower frequency bound at f_min and the upper frequency bound at f_max
if f_min > f_max:
self.f_min, self.f_max = f_max, f_min
else:
self.f_min, self.f_max = f_min, f_max
# Choosing n frequencies logarithmicaly equally spaced between the bounds given
self.set_freq(self.f_min, self.f_max)
self.a, self.f1, self.e1 = a, f1, e1
def check_inputs(self):
"""
Check the validity of the inputs.
"""
super(Crim, self).check_inputs()
try:
d = [float(i) for i in
[self.f_min, self.f_max, self.a]]
except ValueError:
sys.exit("The inputs should be numeric.")
if (np.array(d) < 0).sum() != 0:
sys.exit("The inputs should be positive.")
if len(self.f1) != len(self.e1):
sys.exit("Number of volumetric volumes does not match the dielectric properties")
# Check if the materials are at least two
if len(self.f1) < 2:
sys.exit("The materials should be at least 2")
# Check if the frequency range is null
if self.f_min == self.f_max:
sys.exit("Null frequency range")
# Check if the inputs are positive
f = [i for i in self.f1 if i < 0]
if len(f) != 0:
sys.exit("Error: The inputs should be positive")
for i in range(0, len(self.f1)):
f = [i for i in self.e1[i][:] if i < 0]
if len(f) != 0:
sys.exit("Error: The inputs should be positive")
# Check if the summation of the volumetric fractions equal to one
if np.sum(self.f1) != 1:
sys.exit("Error: The summation of volumetric volumes should be equal to 1")
def print_info(self):
"""
Print information about chosen approximation settings
"""
print(f"Approximating Complex Refractive Index Model (CRIM)"
f" using {self.number_of_debye_poles} Debye poles")
print("CRIM parameters : ")
for i in range(0, len(self.f1)):
print("Material {} :".format(i+1))
print("---------------------------------")
print(" Vol. fraction = {}".format(self.f1[i]))
print(" e_inf = {}".format(self.e1[i][0]))
print(" De = {}".format(self.e1[i][1]))
print(" log(t0) = {}".format(np.log10(self.e1[i][2])))
def calculation(self):
"""Calculates the Crim function for the given parameters"""
q = np.zeros(len(self.freq))
for i in range(len(self.f1)):
q = q + self.f1[i]*np.array(
[self.e1[i][0] + self.e1[i][1] /
(np.array(1 + np.array(1j * 2 * np.pi * f * self.e1[i][2])))
for f in self.freq])**self.a
return q**(1 / self.a)
class Rawdata(Relaxation):
def __init__(self, number_of_debye_poles,
filename,
sigma, mu, mu_sigma,
material_name, plot=False, save=True,
optimizer=Particle_swarm,
optimizer_options={}):
"""
Interpolate data given from a text file.
Args:
number_of_debye_poles (int): Number of Debye functions used to
approximate the given electric
permittivity.
filename (str): text file which contains three columns:
frequency (Hz),Real,Imaginary (separated by comma).
sigma (float): Conductivity.
mu (float): Relative permabillity.
mu_sigma (float): Magnetic looses.
material_name (str): A string containing the given name of
the material (e.g. "Clay").
plot (bool): if True will plot the actual and the approximated
permittivity (it can be neglected).
The argument is optional and if neglected plot=False.
save (bool): if True will save approximated material parameters
The argument is optional and if neglected save=False.
optimizer (Optimizer class): chosen optimization method:
Particle Swarm, Genetic or Dual Annealing.
optimizer_options (dict): Additional keyword arguments passed to
optimizer class (Default: empty dict).
"""
super(Rawdata, self).__init__(number_of_debye_poles,
sigma, mu, mu_sigma,
material_name, plot, save,
optimizer, optimizer_options)
self.filename = filename
def check_inputs(self):
"""
Check the validity of the inputs.
"""
super(Rawdata, self).check_inputs()
if not os.path.isfile(self.filename):
sys.exit("File doesnt exists!")
def print_info(self):
"""
Print information about chosen approximation settings
"""
print(f"Approximating the function given"
f" from file name {self.filename}"
f" using {self.number_of_debye_poles} Debye poles")
def calculation(self):
"""
Interpolate real and imaginary part from data.
Column framework of the input file three columns comma-separated
Frequency(Hz),Real,Imaginary
"""
# Read the file
with open(self.filename) as f:
try:
array = np.array(
[[float(x) for x in line.split(",")] for line in f]
)
except ValueError:
sys.exit("Error: The inputs should be numeric")
self.set_freq(min(array[:, 0]), max(array[:, 0]))
rl_interp = scipy.interpolate.interp1d(array[:, 0], array[:, 1])
im_interp = scipy.interpolate.interp1d(array[:, 0], array[:, 2])
return rl_interp(self.freq) - 1j * im_interp(self.freq)
if __name__ == "__main__":
setup = Rawdata(3, "Test.txt", 0.1, 1, 0.1, "M1", plot=True,
optimizer_options={'seed':111,
'pflag':True})
setup.run()
setup = HavriliakNegami(6, 1e12, 1e-3, 0.5, 1, 10, 5,
1e-6, 0.1, 1, 0, "M2", plot=True,
optimizer=Dual_annealing,
optimizer_options={'seed':111,
'maxiter':50})
setup.run()
setup = Jonscher(4, 1e6, 1e-5, 50, 1, 1e5, 0.7,
0.1, 1, 0.1, "M3", plot=True,
optimizer_options={'seed':111})
setup.run()
f = [0.5, 0.5]
material1 = [3, 25, 1e6]
material2 = [3, 0, 1e3]
materials = [material1, material2]
setup = Crim(2, 1*1e-1, 1e-9, 0.5, f, materials, 0.1,
1, 0, "M4", plot=True,
optimizer_options={'seed':111})
setup.run()