Inferring the number of topics for gensim’s LDA – perplexity, CM, AIC …

Having negative perplexity apparently is due to infinitesimal probabilities being converted to the log scale automatically by Gensim, but even though a lower perplexity is desired, the lower bound value denotes deterioration (according to this), so the lower bound value of perplexity is deteriorating with a larger number of topics in my figures …

https://stats.stackexchange.com/questions/322809/inferring-the-number-of-topics-for-gensims-lda-perplexity-cm-aic-and-bic