Update gensim word2vec model

Question

I have a word2vec model in gensim trained over 98892 documents. For any given sentence that is not present in the sentences array (i.e. the set over which I trained the mode

Answer 1

First of all, you cannot add new words to a pre-trained model's.

However, there's a "new" doc2vec model published in 2014 which meets all your requirement. You can use it to train a document vector instead of getting a set of word vector then combine them. The best part is doc2vec can infer unseen sentences after training. Although the model is still unchangable, you can get a pretty good inference result based on my experiment.