Gensim Word2Vec or FastText build vocab from frequency

Question

I wonder what does .build_vocab_from_freq() function from gensim actually do? What is the difference when I'm not using it? Thank you!

Answer 1

It "builds a vocabulary from a dictionary of word frequencies". You need a vocabulary for your gensim models. Usually you build it from your corpus. This is basically an alternative option to build your vocabulary from a word frequencies dictionary. Word frequencies for example are usually used to filter low or high frequent words which are meaningless for your model.