A python implementation of the transfer matrix method for acoustics. It allows the calculation of the reflection index for arbitrary systems of plane absorbing layers and for arbitrary angles of incidence.

Clone this repository, cd into it and execute:

python setup.py develop

The following code snippet calculates the reflection index of a typical absorber with a thickness of 10cm for a normally impinging sound wave.

import numpy
from pytmm import LayeredSystem, Material, Layer

ls = LayeredSystem(1.205, Material(1, 0, 1))
ls.add_layer_in_back(Layer(.1, Material(.99, 10000, 1.4)))

frequency = 1000
omega = 2*np.pi*frequency
k = omega/343

ls.get_rigid_backed_ri(omega, *LayeredSystem.get_kx_ky(0, k))