This example demonstrates a stacked bar chart built with D3.js v5 and rendered as SVG within a React application. The chart visualizes five data points, each with three numeric keys (p, d, e), using `d3.stack()` to compute layer offsets and `d3.scaleBand()` and `d3.scaleLinear()` for positioning. Rectangles are appended via data joins inside groups, with each layer’s fill color assigned sequentially. The code includes placeholder divs for map and sankey visualizations, though only the bar chart is implemented.