Homework 7

<!DOCTYPE html>
<meta charset="utf-8">
<style>
  
path.counties, path.county-border {
  fill: none;
  stroke: #000;
  stroke-opacity: .2;
}
path.state {
  fill: none;
  stroke: #000;
}
path.quake, circle.quake {
  fill: crimson;
  fill-opacity: 0.4;
}

</style>
<svg width="960" height="960"></svg>
<script src="//d3js.org/d3.v4.min.js"></script>
<script src="//d3js.org/d3-tile.v0.0.min.js"></script>
<script src="//d3js.org/topojson.v1.min.js"></script>
<script>

var pi = Math.PI,
    tau = 2 * pi;

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

var projection = d3.geoMercator()
    .scale((1 << 15) / tau)
    .translate([width / 2, height / 2])
    .center([-98.5355, 32.965]);

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

d3.json("ok-counties.json", function(error, ok) {
  if (error) throw error;

var tiles = d3.tile()
      .size([width, height])
      .scale(projection.scale() * tau)
      .translate(projection([0, 0]))
      ();

svg.selectAll("image")
      .data(tiles)
    .enter().append("image")
      .attr("xlink:href", function(d) { return "https://" + "abc"[d[1] % 3] + ".tile.openstreetmap.org/" + d[2] + "/" + d[0] + "/" + d[1] + ".png"; })
      .attr("x", function(d) { return (d[0] + tiles.translate[0]) * tiles.scale; })
      .attr("y", function(d) { return (d[1] + tiles.translate[1]) * tiles.scale; })
      .attr("width", tiles.scale)
      .attr("height", tiles.scale);
 svg.append("path")
      .attr("translate", "path.counties")
      .datum(topojson.mesh(ok, ok.objects.ok))
      .attr("d", path);
});

</script>

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

https://d3js.org/d3-tile.v0.0.min.js

https://d3js.org/topojson.v1.min.js