Making a bar chart
This example shows a smiley face drawn with D3.js, featuring yellow circular head, eyes, eyebrows, and a mouth arc. The eyebrows animate upward and downward over two seconds using chained transitions, demonstrating fundamental DOM manipulation and SVG rendering. The code uses `d3.select`, `svg.append`, `d3.arc` for the mouth path, and `transition.attr` to animate the eyebrow group’s transform. The visualization is purely programmatic, with no external data source, showcasing how D3 can create and animate shapes directly in the browser.