def test_exact():
# Reference: Philip (1960) Table 1, No. 13
# https://doi.org/10.1071/PH600001
theta = fronts.solve(D="0.5*(1 - log(theta))", i=0, b=1)
o = np.linspace(0, 20, 100)
assert_allclose(theta(o=o), np.exp(-o), atol=1e-3)
def test_exact_solve():
o = np.linspace(0, 20, 100)
D = fronts.inverse(o=o, samples=np.exp(-o))
theta = fronts.solve(D=D, b=1, i=0)
assert_allclose(theta(o=o), np.exp(-o), atol=2e-3)
def test_HF135():
r = np.array([
0., 0.0025, 0.005, 0.0075, 0.01, 0.0125, 0.015, 0.0175, 0.02, 0.0225,
0.025, 0.0275, 0.03, 0.0325, 0.035, 0.0375, 0.04, 0.0425, 0.045,
0.0475, 0.05
])
t = 60
# Data obtained with the porousMultiphaseFoam toolbox, version 1906
# https://github.com/phorgue/porousMultiphaseFoam
theta_pmf = np.array([
0.945, 0.944845, 0.944188, 0.942814, 0.940517, 0.937055, 0.93214,
0.925406, 0.916379, 0.904433, 0.888715, 0.868016, 0.840562, 0.803597,
0.752494, 0.678493, 0.560999, 0.314848, 0.102755, 0.102755, 0.102755
])
U_pmf = np.array([
2.66135e-04, 2.66133e-04, 2.66111e-04, 2.66038e-04, 2.65869e-04,
2.65542e-04, 2.64975e-04, 2.64060e-04, 2.62644e-04, 2.60523e-04,
2.57404e-04, 2.52863e-04, 2.46269e-04, 2.36619e-04, 2.22209e-04,
1.99790e-04, 1.61709e-04, 7.64565e-05, -2.45199e-21, -7.35598e-21,
0.00000e+00
])
epsilon = 1e-7
# Wetting of an HF135 membrane, Van Genuchten model
# Data from Buser (PhD thesis, 2016)
# http://hdl.handle.net/1773/38064
theta_range = (0.0473, 0.945)
k = 5.50e-13 # m**2
alpha = 0.2555 # 1/m
n = 2.3521
theta_i = 0.102755 # Computed from P0
theta_b = theta_range[1] - epsilon
D = fronts.D.van_genuchten(n=n, alpha=alpha, k=k, theta_range=theta_range)
theta = fronts.solve(D=D, i=theta_i, b=theta_b, itol=1e-7)
assert_allclose(theta(r, t), theta_pmf, atol=1e-3)
assert_allclose(theta.flux(r, t), U_pmf, atol=1e-6)
def test_badDb():
with pytest.raises(ValueError):
theta = fronts.solve(D="theta", i=1, b=-1)
def test_badDi():
with pytest.raises(ValueError):
theta = fronts.solve(D="theta", i=-0.1, b=1)
epsilon = 1e-7
# Wetting of an HF135 membrane, Van Genuchten model
# Data from Buser (PhD thesis, 2016)
# http://hdl.handle.net/1773/38064
theta_range = (0.0473, 0.945)
k = 5.50e-13 # m**2
alpha = 0.2555 # 1/m
n = 2.3521
theta_i = 0.102755 # Computed from P0
theta_b = theta_range[1] - epsilon
D = van_genuchten(n=n, alpha=alpha, k=k, theta_range=theta_range)
theta = solve(D=D, i=theta_i, b=theta_b, verbose=2)
fig = plt.figure()
fig.canvas.set_window_title("Water content plot")
plt.title("Water content field at t={} {}".format(validation.t,
validation.t_unit))
plt.plot(validation.r,
theta(validation.r, validation.t),
color='steelblue',
label="Fronts")
plt.plot(validation.r,
validation.theta,
color='sandybrown',
label=validation.name)
plt.xlabel("position [{}]".format(validation.r_unit))
epsilon = 1e-7
# Wetting of an HF135 membrane, Van Genuchten model
# Data from Buser (PhD thesis, 2016)
# http://hdl.handle.net/1773/38064
theta_range = (0.0473, 0.945)
k = 5.50e-13 # m**2
alpha = 0.2555 # 1/m
n = 2.3521
theta_i = 0.102755 # Computed from P0
theta_b = theta_range[1] - epsilon
D_analytical = van_genuchten(n=n, alpha=alpha, k=k, theta_range=theta_range)
analytical = solve(D=D_analytical, i=theta_i, b=theta_b)
o = np.linspace(analytical.o[0], analytical.o[-1], 2000)
theta = analytical(o=o)
D_inverse = inverse(o=o, samples=theta)
fig = plt.figure()
fig.canvas.set_window_title("Diffusivity plot")
plt.title("Diffusivity function")
plt.plot(theta, D_analytical(theta), label="Analytical")
plt.plot(theta, D_inverse(theta), label="Obtained with inverse()")
plt.xlabel("water content [-]")
plt.ylabel("diffusivity [{}**2/{}]".format(validation.r_unit,
# Data from Buser (PhD thesis, 2016)
# http://hdl.handle.net/1773/38064
theta_range = (0.0473, 0.945)
k = 5.50e-13 # m**2
alpha = 0.2555 # 1/m
n = 2.3521
theta_i = 0.102755 # Computed from P0
theta_b = theta_range[1] - epsilon
D = van_genuchten(n=n, alpha=alpha, k=k, theta_range=theta_range)
print("----Starting solution----")
coarse = solve(D=D,
i=theta_i,
b=theta_b,
itol=5e-2,
d_dob_bracket=(-1, 0),
verbose=2)
print()
print("----Refined with solve()----")
fine = solve(D=D,
i=theta_i,
b=theta_b,
d_dob_bracket=coarse.d_dob_bracket,
verbose=2)
o_guess = fine.o
guess = coarse(o=o_guess)
print()
#!/usr/bin/env python
"""
This example solves a problem that has an exact solution (using `fronts.solve`)
and compares the solutions.
"""
from __future__ import division, absolute_import, print_function
import numpy as np
import matplotlib.pyplot as plt
from fronts import solve
theta = solve(D="0.5*(1 - log(theta))", i=0, b=1, verbose=2)
o = np.linspace(0, 20, 200)
fig = plt.figure()
fig.canvas.set_window_title("theta plot")
plt.title("theta(o)")
plt.plot(o, theta(o=o), color='steelblue', label="Fronts")
plt.plot(o, np.exp(-o), color='sandybrown', label="Exact")
plt.xlabel("o")
plt.ylabel("theta")
plt.grid(which='both')
plt.legend()
plt.show()
from __future__ import division, absolute_import, print_function
import matplotlib.pyplot as plt
from fronts import solve, inverse, o
import validation
D_inverse = inverse(o=o(validation.r, validation.t)[::5],
samples=validation.theta[::5])
# Using only a fifth of the points so that it does not run too slow
theta = solve(D=D_inverse,
i=validation.theta[-1],
b=validation.theta[0],
itol=5e-3,
verbose=2)
fig = plt.figure()
fig.canvas.set_window_title("Water content plot")
plt.title("Water content field at t={} {}".format(validation.t,
validation.t_unit))
plt.plot(validation.r,
validation.theta,
label="Original ({})".format(validation.name))
plt.plot(validation.r,
theta(validation.r, validation.t),
label="Reconstructed with inverse() and solve()")
plt.xlabel("r [{}]".format(validation.r_unit))
#!/usr/bin/env python
"""Example of usage of `fronts.solve`."""
from __future__ import division, absolute_import, print_function
import numpy as np
import matplotlib.pyplot as plt
from fronts import solve
from fronts.D import power_law
k = 4.0
ci = 0.1
cb = 1.0
c = solve(D=power_law(k=k), i=ci, b=cb, verbose=2)
r = np.linspace(0, 10, 200)
fig = plt.figure()
fig.canvas.set_window_title("c plot")
plt.title("c field")
plt.plot(r, c(r, t=30), label="t=30")
plt.plot(r, c(r, t=60), label="t=60")
plt.xlabel("r")
plt.ylabel("S")
plt.grid(which='both')
plt.legend()
fig = plt.figure()
from __future__ import division, absolute_import, print_function
import numpy as np
import matplotlib.pyplot as plt
from fronts import solve, inverse
from fronts.D import power_law
k = 4.0
D = power_law(k=k)
c1i = 0.1
c1b = 1.0
c1 = solve(D, i=c1i, b=c1b, verbose=2)
c2i = 1.0
c2b = 0.1
c2 = solve(D, i=c2i, b=c2b, verbose=2)
# Reverse Sb and Si
r = np.linspace(0, 30, 200)
t = 60
fig = plt.figure()
fig.canvas.set_window_title("c plot")
plt.title("c field at t={}".format(t))
from fronts import solve
from fronts.D import van_genuchten
import validation
epsilon = 1e-6
Ks = 25 # cm/h
alpha = 0.01433 # 1/cm
n = 1.506
theta_range = (0, 0.3308)
D = van_genuchten(n=n, alpha=alpha, Ks=Ks, theta_range=theta_range)
theta = solve(D=D, i=0.1003, b=0.3308 - epsilon, verbose=2)
fig = plt.figure()
fig.canvas.set_window_title("Water content plot")
plt.title("Water content fields")
for t, theta_ in zip(validation.t, validation.theta):
plt.plot(validation.r,
theta(validation.r, t),
label="Fronts, t={} {}".format(t, validation.t_unit))
plt.plot(validation.r,
theta_,
label="{}, t={} {}".format(validation.name, t, validation.t_unit))
plt.xlabel("r [{}]".format(validation.r_unit))
plt.ylabel("water content [-]")
plt.grid(which='both')
