How to see the words shared across topics in LDA model?

Question

I am trying to find the words that are shared across the topics and words unique to a topic using LDA model in R. Is there any package or function?

Thanks

Answer 1

All words are shared among all topics, just with different probabilities, since a topic is just a probability distribution over the words.

Of course it is customary to display TOP-$n$ words to quote a topic. You may ask then which words in the TOP-10 or TOP-20 are shared between some topics. I don't know how to do this in R, I'd use a hash in perl or python to achieve this goal.