Infant Mortality Choropleth

A choropleth map of infant mortality rates by county from 1999-2015.

Source: CDC WONDER Compressed Mortality, 1999-2015.

Group results by County
Pick Age Group <1 year

WONDER exports tab-separated values which are loaded and parsed with d3.tsv. To make the file compatible, remove all the rows after and including "Total".

Part of an exploration in American mortality trends with Debby Oh.

Based on Choropleth by Mike Bostock.

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

body {
    font-family: "Helvetica Neue", Helvetica, sans-serif;;
    font-size: 12px;
    width: 960px;
    height: 500px;
    margin: 20px auto;
  }
  .states {
    stroke: #fff;
    fill: none;
    pointer-events: none;
  }
  .counties {
    stroke: #fff;
    fill: green;
    stroke-width: .3px;
  }
  .tooltip {
    background: rgba(0, 0, 0, 0.85);
    color: #f9f9f9;
    padding: 8px;
  }
  .tooltip h3 {
    margin: 0px 0px 8px;
  }
</style>

<body>

</body>

var color = d3.scaleThreshold()
  .range(["#fde0dd","#fcc5c0","#fa9fb5","#f768a1","#dd3497","#ae017e","#7a0177","#49006a"])
  .domain([250, 500, 750, 1000, 1250, 1500, 1750, 2000]);

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

var tooltip = d3.select("body")
    .append("div")
    .attr("class", "tooltip")
    .style("position", "absolute")
    .style("z-index", "10")
    .style("visibility", "hidden");

d3.queue()
    .defer(d3.tsv, "infants-1999-2015.txt")
    .defer(d3.json, "us.json")
    .await(ready);

function ready(error, deaths, us) {
  if (error) return console.warn(error);

deathsByFips = {};
  deaths.forEach(function(d) {
    d.Deaths = +d.Deaths;
    d.Population = +d.Population;
    d["Crude Rate"] = +(d["Crude Rate"].replace(" (Unreliable)", ""));
    deathsByFips[+d["County Code"]] = d;
  });

// uncomment to see extent of mortality rate (min/max counties)
  //console.log(d3.extent(deaths, function(d) { return d["Crude Rate"] }));

var format = d3.format(".2%");
  var commas = d3.format(",");

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

var subset = topojson.feature(us, us.objects.counties).features.filter(function(d) {
    return d.id in deathsByFips;
  });

svg.append("g")
      .attr("class", "counties")
    .selectAll("path")
      .data(subset)
    .enter().append("path")
      .attr("d", path)
      .style("fill", function(d) { 
        return color(deathsByFips[d.id]["Crude Rate"]);
      })
      .on("mouseover", function(d) {
        var val = deathsByFips[d.id];
        var fill_color = color(val["Crude Rate"]);
        tooltip.html("");
        tooltip.style("visibility", "visible")
          .style("border", "3px solid " + fill_color);

tooltip.append("h3").text(val.County);
        tooltip.append("div")
          .text("Infants: " + commas(val["Population"]));
        tooltip.append("div")
          .text("Deaths: " + commas(val["Deaths"]));
        tooltip.append("div")
          .text("Mortality Rate: " + format(val["Crude Rate"]/100000));

d3.selectAll(".counties path")
          .style("opacity", 0.3)
          .style("stroke", null);
        d3.select(this)
          .style("opacity", 1)
          .style("stroke", "#222")
          .raise();
        d3.selectAll(".states")
          .style("opacity", 0);
      })
      .on("mousemove", function() {
        return tooltip.style("top", (d3.event.pageY-52) + "px").style("left", (d3.event.pageX+18) + "px");
      })
      .on("mouseout", function() {
        tooltip.style("visibility", "hidden")
        d3.selectAll(".counties path")
          .style("opacity", 1);
        d3.selectAll(".states")
          .style("opacity", 1);
      });

svg.append("path")
      .datum(topojson.mesh(us, us.objects.states, function(a, b) { return a.id !== b.id; }))
      .attr("class", "states")
      .attr("d", path);

svg.append("text")
    .style("font-weight", "bold")
    .attr("x", width - 176)
    .attr("y", height - 152)
    .text("Infant Mortality");

var legend = svg.selectAll(".legend")
    .data(color.domain().reverse())
    .enter().append("g")
    .attr("transform", function(d,i) {
      return "translate(" + (width-139) + "," + (height - 144 + 16 * i) + ")";
    })

legend.append("rect")
    .attr("width", 12)
    .attr("height", 12)
    .style("fill", function(d) {
      return color(d);
    });

legend.append("text")
    .attr("x", 16)
    .attr("y", 11)
    .style("font-size", "12px")
    .text(function(d) {
      return format(d/100000);
    });
}

</script>

Modified http://d3js.org/d3.v4.js to a secure url

Modified http://d3js.org/topojson.v1.min.js to a secure url

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

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