FLaREON : a fast computation of Ly$\alpha$ escape fractions and line
  profiles
  We present FLaREON (Fast Lyman-Alpha Radiative Escape from Outflowing Neutral
gas), a public python package that delivers fast and accurate Lyman alpha
escape fractions and line profiles over a wide range of outflow geometries and
properties. The code incorporates different algorithms, such as interpolation
and machine learning to predict Lyman alpha line properties from a pre-computed
grid of outflow configurations based on the outputs of a Monte Carlo radiative
transfer code. Here we describe the algorithm, discuss its performance and
illustrate some of its many applications. Most notably, FLaREON can be used to
infer the physical properties of the outflowing medium from an observed Lyman
alpha line profile, including the escape fraction, or it can be run over
millions of objects in a galaxy formation model to simulate the escape of Lyman
alpha photons in a cosmological volume.
