This example shows the relationship between car horsepower and highway MPG using two coordinated visualizations. The scatter plot encodes car category (Economy, Standard, Luxury, Sports) with color via d3.scaleOrdinal, while the bar chart, rendered with Chart.js on a canvas, displays average horsepower grouped by car make, colored by brand category. The code loads data from bubblechart.csv using Papa.parse, with d3.v7 handling the SVG axes, scales, and scatter plot circles. The bar chart sorts makes by descending average horsepower.