This example shows a butterfly chart comparing the Teaching, Research, and Citation ratings of a single university, Caltech, using two horizontal bars that extend symmetrically from a central axis. The left side uses royalblue bars, while the right uses steelblue, with numeric values labeled above each bar. Built with D3 v7 in an SVG, the code converts the first row of CSV data into long format, then uses `d3.scaleLinear` for the bar lengths and `d3.scaleBand` for row positioning.