block by mbostock 4090870

U.S. Counties TopoJSON Mesh

Full Screen

A demo of TopoJSON on a U.S. counties shapefile from the U.S. census bureau.

index.html

<!DOCTYPE html>
<svg width="960" height="600"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script src="https://d3js.org/topojson.v2.min.js"></script>
<script>

var svg = d3.select("svg");

d3.json("https://d3js.org/us-10m.v1.json", function(error, us) {
  if (error) throw error;

  var path = d3.geoPath(),
      mesh = topojson.mesh(us),
      transform = topojson.transform(us);

  svg.append("path")
      .attr("fill", "none")
      .attr("stroke", "#000")
      .attr("stroke-width", 0.25)
      .attr("stroke-linejoin", "round")
      .attr("d", path(mesh));

  svg.selectAll("circle")
    .data(us.arcs)
    .enter().append("circle")
      .attr("transform", function(d) { return "translate(" + transform(d[0]) + ")"; })
      .attr("r", 1.25);
});

</script>