MaartenGr / MaartenGr/BERTopic
Topics returned from model.transform differ from model.fit_transform
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Description
Hi,
When I run BERTopic using model.fit_transform on my dataset, it will return cluster numbers and titles that make sense for the input data. When I run the same string through the trained model using model.transform, it returns a different cluster number, though it is consistent. For example, something with "Mexican restaurant" might get assigned to topic 1 "restaurant_mexican restaurant_full service restaurant", but when I run the exact same record through model.transform, I'll get a different integer for the topic (corresponding to something totally different) and even a different probability - and these can even differ between runs of model.transform on the same trained model. Am I doing something wrong? This has been befuddling me. Note the topic numbers from model.get_topic_info and those returned from model.fit_transform do correspond with one another.
Perhaps related, but I saw a similar frustrating difference in the outputs of get_topic_info and the output when using calculate_probabilities=True, where the columns of the probability array did not correspond to the topic numbers from get_topic_info.
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Research direction
Reproduce the mismatch by comparing model.fit_transform, model.transform, get_topic_info, and calculate_probabilities on the same records. Trace how topic IDs and probability columns are produced and mapped; done means repeated transforms return stable assignments whose IDs and probability columns correspond to get_topic_info.
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Assessment
- Tech stack
- python
- Domain
- machine-learning
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 35/100