Major Release v0.8

Mainly a visualization update to improve understanding of the topic model.

Features

• Additional visualizations:
  • Topic Hierarchy: topic_model.visualize_hierarchy()
  • Topic Similarity Heatmap: topic_model.visualize_heatmap()
  • Topic Representation Barchart: topic_model.visualize_barchart()
  • Term Score Decline: topic_model.visualize_term_rank()

Improvements

• Created bertopic.plotting library to easily extend visualizations
• Improved automatic topic reduction by using HDBSCAN to detect similar topics
• Sort topic ids by their frequency. -1 is the outlier class and contains typically the most documents. After that 0 is the largest topic, 1 the second largest, etc.
• Update MKDOCS with new visualizations

Fixes

• Fix typo #113, #117
• Fix #121 by removing the following two lines:
  • https://github.com/MaartenGr/BERTopic/blob/5c6cf22776fafaaff728370781a5d33727d3dc8f/bertopic/_bertopic.py#L359-L360
• Fix mapping of topics after reduction (it now excludes 0) (#103)