Centroid Counties [UNLISTED]

This example uses d3.geo.bounds to draw a diagonal line for the bounding box for each county.

forked from mbostock's block: Fuzzy Counties

<!DOCTYPE html>
<meta charset="utf-8">
<style>

path {
  fill: none;
  stroke: steelblue;
}

</style>
<body>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script src="https://d3js.org/topojson.v2.min.js"></script>
<script>

var width = 960,
    height = 500;

var projection = d3.geoAlbersUsa()
    .scale(1000)
    .translate([width / 2, height / 2]);

var path = d3.geoPath()
    .projection(projection);

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);

d3.json("https://gist.githubusercontent.com/mbostock/4090846/raw/d534aba169207548a8a3d670c9c2cc719ff05c47/us.json", function(error, us) {
  if (error) throw error;

var centroids = topojson.feature(us, us.objects.counties).features
            .filter(function(d) { return d.geometry && d.geometry.coordinates.length; })
            .map(d3.geoCentroid);
  
  console.log(centroids)
  
  svg.append("path")
      .attr("d", path({
        type: "MultiPoint",
        coordinates: centroids
      }));
});

</script>

https://d3js.org/d3.v4.min.js

https://d3js.org/topojson.v2.min.js