Show HN: Filter and read Hacker News by category
blog.monkeylearn.com
blog.monkeylearn.com
Personally, I don't really see a reason for the chart. It would be nice to have a way to disable it.
You could try using clustering instead (K-means) to group the posts together into their own categories. This is similar to a "trending topics" approach, where the categories could change each day.
Also, there's no obvious way to indicate an incorrect categorization (like the one about Ripple being fined; that fits better in "business" or even "politics", yet is the top result in "science" right now). If it's machine-learning-based, it's probably much more useful to be continuously learning based on user feedback rather than generating a model and sticking with it forever (especially when the model is visibly inaccurate in some circumstances).
Also, the job postings should probably be a separate category instead of being lumped into business.