wtf is matrix-pro-tableau?

Matrix Pro is a free add on for Tableau, the data visualization tool many companies use for dashboards. It adds a chart type that Tableau does not offer on its own: a hierarchical matrix table, similar to the pivot tables found in Power BI, where rows and columns can be grouped into multiple levels and expanded or collapsed with plus and minus buttons. Once installed on a dashboard, the matrix can show subtotals and grand totals automatically, and lets you color cells based on their values, either with a smooth gradient between a minimum and maximum color, or with rules that assign specific colors to value ranges. Text color adjusts automatically between white and dark grey depending on how bright the background color is, so labels stay readable. Three built in visual themes are included, along with adjustable spacing and font sizes, and the whole interface can switch between six languages: English, Spanish, Chinese, German, Italian, and French. Behind the scenes, the extension listens to whatever fields you drop into Tableau's Rows, Columns, and Values areas, reorganizes that flat data into a nested tree, and renders it as an interactive table using plain web technologies, with no server needed beyond the already hosted extension file. Finished tables can be exported to Excel or CSV with one click. To use it, a Tableau dashboard needs an Extension object pointing at the project's manifest file, which by default loads a version already hosted on GitHub Pages, so no separate setup is required beyond adding the extension to a dashboard. Developers who want to run a local copy can do so with a simple static web server. The project is released under the MIT license, meaning it can be used, modified, and redistributed freely, including for commercial dashboards.