mbostock/.block

## .block
license: gpl-3.0
height: 600
border: no
redirect: https://observablehq.com/@d3/u-s-map

## README.md

      
    Raw
  

              README.md
            
          
    These county, state and country boundaries are extracted from a single TopoJSON file from us-atlas. Counties are stroked in thin gray, states in thin black, and the country in thick black. See also the fancy drop shadow variant.

  
## index.html
<!DOCTYPE html>
<svg width="960" height="600" fill="none" stroke="#000" stroke-linejoin="round" stroke-linecap="round"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script src="https://unpkg.com/topojson-client@3"></script>
<script>

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

var path = d3.geoPath();

d3.json("https://unpkg.com/us-atlas@1/us/10m.json", function(error, us) {
  if (error) throw error;

  svg.append("path")
      .attr("stroke", "#aaa")
      .attr("stroke-width", 0.5)
      .attr("d", path(topojson.mesh(us, us.objects.counties, function(a, b) { return a !== b && (a.id / 1000 | 0) === (b.id / 1000 | 0); })));

  svg.append("path")
      .attr("stroke-width", 0.5)
      .attr("d", path(topojson.mesh(us, us.objects.states, function(a, b) { return a !== b; })));

  svg.append("path")
      .attr("d", path(topojson.feature(us, us.objects.nation)));
});

</script>

## thumbnail.png

      
    Raw
  

              thumbnail.png
	license: gpl-3.0
	height: 600
	border: no
	redirect: https://observablehq.com/@d3/u-s-map
	<!DOCTYPE html>
	<svg width="960" height="600" fill="none" stroke="#000" stroke-linejoin="round" stroke-linecap="round"></svg>
	<script src="https://d3js.org/d3.v4.min.js"></script>
	<script src="https://unpkg.com/topojson-client@3"></script>
	<script>

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

	var path = d3.geoPath();

	d3.json("https://unpkg.com/us-atlas@1/us/10m.json", function(error, us) {
	if (error) throw error;

	svg.append("path")
	.attr("stroke", "#aaa")
	.attr("stroke-width", 0.5)
	.attr("d", path(topojson.mesh(us, us.objects.counties, function(a, b) { return a !== b && (a.id / 1000 \| 0) === (b.id / 1000 \| 0); })));

	svg.append("path")
	.attr("stroke-width", 0.5)
	.attr("d", path(topojson.mesh(us, us.objects.states, function(a, b) { return a !== b; })));

	svg.append("path")
	.attr("d", path(topojson.feature(us, us.objects.nation)));
	});

	</script>