xopto.pf.miemixture module¶

class MieMixture(miepds: Tuple[xopto.pf.miepd.MiePd], weights: list)[source]¶

Bases: xopto.pf.pfbase.PfBase

Scattering phase function of a mixture of MiePd scattering phase functions.

Parameters

miepds` (list or tuple of MiePd) – A list of scattering phase functions.
weights (tuple, list or numpy.ndarray) – Weights of the individual scattering phase functions. The sum of weights should equal 1.

Examples

Scattering phase functions of a mixture of Normally distributed microspherical particles: 1. mean diameter 0.5 um, standard deviation 15 nm, and weight 0.98, 2. mean diameter 1.0 um, standard deviation 25 nm, and weight 0.02.

>>> from matplotlib import pyplot as pp
>>> import numpy as np
>>> from xopto import pf
>>>
>>> cost_heta = np.linspace(-1.0, 1.0, 1000)
>>> normal1 = pf.MieNormal(0.5e-6, 15e-9, nsphere=1.6, nmedium=1.33, wavelength=550e-9, nd=1000)
>>> normal2 = pf.MieNormal(1e-6, 25e-9, nsphere=1.6, nmedium=1.33, wavelength=550e-9, nd=1000)
>>> mixture = pf.MieMixture((normal1, normal2), (0.98, 0.02))
>>>
>>> pp.figure()
>>> pp.semilogy(cost_heta, mixture(cost_heta), label='Mixture 0.98*N(0.5 um, 15 nm) + 0.02*N(1 um, 25 nm)')
>>> pp.grid()
>>> pp.legend()
>>> pp.show()
>>>

acs() → float[source]¶: Returns the absorption cross section.

distribution() → xopto.pf.distribution.Mixture [source]¶

Creates and returns a mixture object that represents the number density of all constituents/components as a function of diameter.

Returns: mixture – A mixture object representing the number density of all constituents/components as a function of diameter.
Return type: distribution.Mixture

ecs() → float[source]¶: Returns the extinction cross section.

fastg(n: int, *args, **kwargs) → float[source]¶: Overloads the PfBase.fastg() method of the base class.

Note

If n is 1, a precalculated g1 is returned.

g(n: int, **kwargs) → float[source]¶: Overloads the PfBase.g() method of the base class. Computes the n-th Legendre moment of the scattering phase function.

Note

If n is 1, a precalculated g1 is returned.

miepd(index: int) → xopto.pf.miepd.MiePd [source]¶

Returns scattering phase function at the specified index.

Parameters: index (int, slice) – Scattering phase function(s) at the specified index/slice.
Returns: miepd – Scattering phase function(s) at the specified index.
Return type: MiePd

pd(diameter: float) → float[source]¶

Evaluates to the number density value at the specified particle diameter.

Parameters: diameter (float) – Particle diameter (m).
Returns: pd – The value of number density function at the specified particle diameter.
Return type: float

scs() → float[source]¶: Returns the scattering cross section.

weight(index: int) → float[source]¶

Returns weight of scattering phase functions at the specified index or slice.

Parameters: index (int, slice) – Index or slice of the selected scattering phase function weight.
Returns: weight – The selected scattering phase function weight(s).
Return type: float or tuple