Calculating Topic Diversity in BERTopic using OCTIS

[ovi97]

Discussed in https://github.com/MaartenGr/BERTopic/discussions/627

^{Originally posted by **ovi97** July 20, 2022} Hello @MaartenGr. Thank you for making BERTopic so flexible to make Topic Modelling to fun to use. Anyways I have several implementations of BERTopic using different Sentence Transformers, Dimensionality Reduction, and Clustering techniques. However, I would love to evaluate these models numerically using different metrics. I have been able to calculate the Coherent scores using Gensim. But I want to calculate Topic Diversity, Pairwise Jaccard Similarity, and other diversity and similarity metrics using the OCTIS library. However, when I checked their implementation here(https://colab.research.google.com/github/MIND-Lab/OCTIS/blob/master/examples/OCTIS_LDA_training_only.ipynb#scrollTo=18Ayd5ZaBrSp), these measures need a dictionary of 1)'test-topic-document-matrix' ---> this is an array 2) 'topic-document-matrix' ---> this is an array 3) 'topic-word-matrix' ---> this is an array 4) topic -----> this is a list of words in each topic I can get the parameters in 4, but can not get the matrices in the first 3. What do these arrays mean and how can they be computed in BERTopic. Thanks

[MaartenGr]

Thank you for posting this question. Seeing as there is a duplicate in the discussions, I will close this issue now in favor of that discussion.