chart = {
const color = d3.scaleQuantize([1, 10], d3.schemeBlues[9]);
const path = d3.geoPath();
const format = d => `${d}%`;
const valuemap = new Map(data.map(d => [d.id, d.rate]));
const counties = topojson.feature(us, us.objects.counties);
const states = topojson.feature(us, us.objects.states);
const statemap = new Map(states.features.map(d => [d.id, d]));
const statemesh = topojson.mesh(us, us.objects.states, (a, b) => a !== b);
const svg = d3.create("svg")
.attr("width", 975)
.attr("height", 610)
.attr("viewBox", [0, 0, 975, 610])
.attr("style", "max-width: 100%; height: auto;");
svg.append("g")
.attr("transform", "translate(610,20)")
.append(() => Legend(color, {title: "Unemployment rate (%)", width: 260}));
svg.append("g")
.selectAll("path")
.data(topojson.feature(us, us.objects.counties).features)
.join("path")
.attr("fill", d => color(valuemap.get(d.id)))
.attr("d", path)
.append("title")
.text(d => `${d.properties.name}, ${statemap.get(d.id.slice(0, 2)).properties.name}\n${valuemap.get(d.id)}%`);
svg.append("path")
.datum(topojson.mesh(us, us.objects.states, (a, b) => a !== b))
.attr("fill", "none")
.attr("stroke", "white")
.attr("stroke-linejoin", "round")
.attr("d", path);
return svg.node();
}