Let us say I have a LDA model trained on a corpus of text. I would like to know, for a newly given document, which one from the corpus is closet to it. But, to do so, I want to use probabilities provided by LDA.
Is it possible to measure a "similarity score" from probabilities?
I guess using classical formula of probability products would result in a very low value. I am newbie to NLP, I don't know much about literature.