Sakht-e-kiran is a set of procedures for determining coincidence rates for passive optical interferometry in terms of the immanats of the scattering matrix.

It was used to generate results published in

Abdullah Khalid, Dylan Spivak, Barry C. Sanders, and Hubert de Guise. Permutational symmetries for coincidence rates in multimode multiphotonic interferometry. Phys. Rev. A, 97:063802, 2018.

Please email abdullahkhalids@gmail.com for help or if you want to use this code in your own work.