This example shows an animated scatter plot of the Iris dataset, cycling through different x-axis variables (petal width, sepal width, petal length, sepal length) while keeping sepal length on the y-axis. The visualization uses D3 v6's `scaleLinear`, `axisLeft`, and `axisBottom` APIs to render SVG circles colored by species, with a custom legend and axis labels. Data is loaded via D3's `csv` function from a GitHub gist, and a `setInterval` timer triggers updates to the plot's x-value mapping.