This example shows average calories per restaurant from a fast food nutrition dataset, with each restaurant represented by a vertical bar. The bar chart is rendered as an SVG using D3 v7, with data processed through `d3.csv` and aggregated via `d3.rollups` and `d3.mean`. Axes are generated with `d3.axisBottom` and `d3.axisLeft`, while scales (`d3.scaleBand`, `d3.scaleLinear`) position the bars and map calorie values.