This example visualizes the classic Iris dataset as a scatter plot, mapping petal width to the x-axis and sepal length to the y-axis. Circles represent individual flowers, with axes labeled via D3’s `scaleLinear`, `axisLeft`, and `axisBottom` APIs. The code loads CSV data using `d3.csv`, parses numerical fields, and renders the plot as SVG circles sized with a fixed radius. The visualization fills the browser window, using viewport dimensions for the chart’s width and height, and demonstrates a straightforward data-joining workflow with `selectAll` and `join`.