Hellinger Distance in Gensim
As u said that one has to train a model in order to calculate Hellinger distance. I am not sure that which model u are talking about but for now I assume that u might have thinking about the latent model so according to me there is not mandatory to train a latent model to produce a document vector. one can create a document vector from the directly word-doc matrix and can calculate Hellinger distance. One simple trick is that I used is first calculate a bag of word representation after getting doc-word matrix by gensim utilities. kindly review it and let me know your opinion.