Editing Lambert W function (section)

=== Statistics ===
The centroid of a set of histograms defined with respect to the symmetrized Kullback–Leibler divergence (also called the Jeffreys divergence <ref>{{cite journal |author=Flavia-Corina Mitroi-Symeonidis |author2=Ion Anghel |author3=Shigeru Furuichi |title=Encodings for the calculation of the permutation hypoentropy and their applications on full-scale compartment fire data |journal=Acta Technica Napocensis |date=2019 |volume=62, IV |pages=607–616}}</ref>) has a closed form using the Lambert {{mvar|W}} function.<ref>[https://ieeexplore.ieee.org/document/6509930 F. Nielsen, "Jeffreys Centroids: A Closed-Form Expression for Positive Histograms and a Guaranteed Tight Approximation for Frequency Histograms"]</ref>