Initial Commit

Examples/silica_data_fit.py

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+"""
+Generates l* values versus particle volume concentration for silica particles with varying form factor models.
+Plots model versus experimental data (courtesy of Qi Li).
+"""
+
+from scattering import *
+import numpy as np
+import matplotlib.pyplot as plt
+
+# Scattering Parameters
+n_p = 1.446  # particle refractive index (silica)
+n_s = 1.332  # medium refractive index (water)
+a_p = 345e-9/2  # particle radii [meters]
+lambda_vac = 685e-9  # wavelength of light in vacuum [meters]
+
+# Generate Parameter Range
+n_range = 100  # number of data points between values
+phi_range = np.linspace(0.03, 0.15, n_range)
+
+# Initialize Result Array
+l_star_phi = np.empty(shape=(n_range, 4))
+
+# Silica Data (courtesy of Qi Li)
+silica_data = np.array([[0.065, 0.067, 0.069, 0.072, 0.075, 0.135],
+                        [0.000230, 0.000225, 0.000216, 0.000215, 0.000205, 0.000130]])
+
+# Collect Scattering Data
+for i in range(n_range):
+    _, _, _,  l_star_phi[i, 0], _ \
+        = mie_scattering(n_p, n_s, a_p, lambda_vac, phi_range[i])
+    _, _, _, l_star_phi[i, 1], _ \
+        = mie_scattering(n_p, n_s, a_p, lambda_vac, phi_range[i], struct='PY')
+    _, _, _, l_star_phi[i, 2], _ \
+        = mie_scattering(n_p, n_s, a_p, lambda_vac, phi_range[i], struct='SHS', optional_params=[0.2, 0.05])
+    _, _, _, l_star_phi[i, 3], _ \
+        = mie_scattering(n_p, n_s, a_p, lambda_vac, phi_range[i], struct='PYAnnulus', optional_params=[1.2*a_p])
+
+# Generate Colors
+n_colors = 4
+colormap = plt.get_cmap('plasma')
+c = np.empty(shape=(n_colors, 3))
+for i in range(n_colors):
+    c[i, :] = colormap.colors[round(256 * i / n_colors)]
+
+# Plot Data
+fig, ax1 = plt.subplots()
+ax1.plot(phi_range, l_star_phi[:, 0]*1e6, label='No Interactions', linewidth=2, c=c[0])
+ax1.plot(phi_range, l_star_phi[:, 1]*1e6, linestyle='--', label='Hard Sphere', linewidth=2, c=c[1])
+ax1.plot(phi_range, l_star_phi[:, 2]*1e6, linestyle=':', label='Sticky Hard Sphere', linewidth=2, c=c[2])
+ax1.plot(phi_range, l_star_phi[:, 3]*1e6, linestyle='-.', label='1.2$a_p$ Excluded Annulus', linewidth=2, c=c[3])
+ax1.plot(silica_data[0, :], silica_data[1, :]*1e6, 'k.', label='Silica Data', markersize=10)
+ax1.legend()
+ax1.set(xlabel=r'$\phi$', ylabel='l* [µm]')
+
+plt.show()