Fuzzy Counties by mbostock

index.html

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

path {
  fill: none;
  stroke: steelblue;
}

</style>
<body>
<script src="//d3js.org/d3.v3.min.js"></script>
<script src="//d3js.org/topojson.v1.min.js"></script>
<script>

var width = 960,
    height = 500;

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

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

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

d3.json("/mbostock/raw/4090846/us.json", function(error, us) {
  if (error) throw error;

  svg.append("path")
      .attr("d", path({
        type: "MultiLineString",
        coordinates: topojson.feature(us, us.objects.counties).features
            .filter(function(d) { return d.geometry && d.geometry.coordinates.length; })
            .map(d3.geo.bounds)
      }));
});

</script>