This example visualizes the Iris dataset as a scatter plot, mapping petal length on the x-axis and sepal length on the y-axis. Each flower is represented by a circle, with positions scaled linearly using d3.scaleLinear and extents from the data. The visualization renders in SVG, drawing circles directly onto an appended svg element. Axes are generated with d3.axisLeft and d3.axisBottom, styled with a 20px font size for tick labels. Data is loaded asynchronously using d3.csv from a remote Gist URL, with numeric parsing applied to all four measurement columns.