mieshah 0.0.3

A Python package to calculate light scattering properties/parameters of spherical particles by using Mie theory.

This Python package calculates light scattering properties/parameters of spheres by using Mie theory.

This has been developed from a mie theory program originally written in FORTRAN and published in the paper: Ghanshyam A. Shah, "Numerical Methods for Mie Theory of Scattering by a Sphere",Kodaikanal Obs. Bull. Soc.(1977) 2, 42-63.

• Python form developed by Dwaipayan Deb (2025)

Install command:

pip install mieshah

Use example:

import mieshah as ms
from matplotlib import pyplot as plt

# ps-> particle radius(microns), wl-> wavelength (microns), m-> complex refractive index (real,imaginary), 
# f-> Size distribution function, incr-> increment for size distribution function
# theta-> Scattering angle (optional) (e.g. theta=30 or theta=[10,45]). If it is not given then default range is [0,180]. 

mymie = ms.miescatter(ps=[0.1,1], wl=6.283185307,m=(1.5,0),f="x**-2",incr=0.01,theta=[10,45])  # With size distribution function and a given theta range
mymie = ms.miescatter(ps=[0.1,1], wl=6.283185307,m=(1.5,0),f="x**-2",incr=0.01)  # With size distribution function with default theta range
mymie = ms.miescatter(ps=100, wl=6.283185307,m=(1.5,0.0),theta=30) # Without size distribution function (single particle) at 30 deg. scattering angle

print(mymie.ps)
print(mymie.wl)
print(mymie.m)
print(mymie.f)
print(mymie.X) # Size parameter
print(mymie.ALBED) # Albedo
print(mymie.QSCA) # Scattering efficiency
print(mymie.QEXT) # Extinction efficiency
print(mymie.QBAK) # Backscattering efficiency
print(mymie.QABS) # Absorption efficiency
print(mymie.QPR) # Radiation pressure efficiency
print(mymie.I_perp) # Intensity perpendicular to the plane of incidence
print(mymie.I_parl) # Intensity parallel to the plane of incidence
print(mymie.Polar) # Degree of linear polarization
print(mymie.p_theta) # Phase function
print(mymie.theta) # Scattering angle in degrees

plt.plot(mymie.theta[::2], mymie.Polar[::2])
plt.xlabel('Theta (degrees)')
plt.ylabel('Polarization')
plt.title('Degree of Linear Polarization')
plt.show()
plt.plot(mymie.theta[::2], mymie.p_theta[::2])
plt.yscale('log')    
plt.xlabel('Theta (degrees)')
plt.ylabel('Phase Function')
plt.title('Phase Function')
plt.show()