Voigt-function evaluation using a two-dimensional interpolation scheme

A method of evaluating the Voigt function for the shape of spectral lines is described. The method relies on interpolation from a two-dimensional table using simply-transformed coordinates. High-level mathematical functions are avoided wherever possible, and no series summations are made. The relative error on a 400 by 100 table is less than 3 × 10^?3 over the region where the interpolation method is faster than other expansions. Computing speed is comparable to that of built-in scientific functions.