chart = {
const svg = d3.create("svg")
.attr("viewBox", [0, 0, 975, 610]);
svg.append("g")
.selectAll("path")
.data(topojson.feature(us, us.objects.states).features)
.join("path")
.attr("fill", d => linearColorScale(pointScale(state_map.get(d.properties.name))))
.attr("d", path)
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();
}