This example presents a dual-view visualization combining an interactive tree diagram and a bar chart. The tree diagram shows a hierarchical dataset with branches for school type, gender, and higher education status, rendered using D3.js SVG primitives. The bar chart displays categorical values from a separate dataset, with animated transitions that redraw the bars and Y-axis when the data updates. Both views rely on D3 v6 APIs such as `d3.select`, `d3.scaleBand`, `d3.scaleLinear`, and the `.join` method for efficient element updates.