[Question] Optimal number of topics in LDA

[carloszimm]

Hi!
I'm planning to use the LDA functionality, and, as I read (I'm very new to the matter), in Gensim there's a coherence score that could be used to determine that (magic) key number. I wonder if there's any similar functionality implemented in the library? I have also read that perplexity may be added to the game to help deciding the number of topics but I'm not quite sure if it is correct or how to use it. I would really appreciate any clarification.

Thank you!

[carloszimm]

After some reading and analyzing carefully the API, I came to the conclusion that right now the only quantitative measure available is perplexity (I have already tested it too). So, If that's right, I think I'll close the issue :)