RALF: RADEX Line Fitter

The RADEX Line Fitter provides a Python 3 interface that calls RADEX (ascl:1010.075) to make a non-LTE fit to a set of observed lines and derive the column density of the molecule that produced the lines and optionally also the molecular hydrogen (H2) number density or the kinetic temperature of the molecule. This code requires RADEX to be installed locally.