This example shows a pie chart where each arc segment represents a portion of a population value, with colors assigned from a categorical ordinal scale. The visualization uses a D3.js layout and SVG rendering, constructing the chart with `d3.svg.arc` for the arcs and `d3.layout.pie` to compute the angles from the data. The chart is centered on an SVG canvas of 960 by 500 pixels, with white strokes separating each arc for clarity. The code relies on D3’s ordinal color range to distinguish the segments visually.