Many, many pie charts

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

html, body {
  height: 100%;
  width: 100%;
  color: #444;
  font: 1em/1 "Hoefler Text", "Georgia", Georgia, serif, sans-serif;
  padding: 10px;

}

#viz {
  height: 100%;
  width: 50%;
  float: left;
}

</style>
<script src="https://d3js.org/d3.v3.min.js"></script>

var pie = d3.layout.pie()
      .sort(null)
      .value(function(d) { return d; });

d3.csv("city-topic-pct.csv", function(error, nodescsv){
    newdata = nodescsv;
    
    gcities = vis.selectAll("g.cities").data(nodescsv).enter().append("g").attr("class", "cities").attr("transform", function(d,i) {return "translate(" + (100 + (i%5 * 90)) + "," + (100 + (i%8 * 50)) + ")"});
    
     var g = gcities.selectAll(".arc")
      .data(function (d) {return pie([d.habitat, d.parks])})
    .enter().append("g")
      .attr("class", "arc");

g.append("path")
      .attr("d", arc)
      .style("fill", function(d,i) { return i==0 ? "green" : "brown"; });

gcities.append("text")
//      .attr("transform", function(d) { return "translate(" + arc.centroid(d) + ")"; })
      .attr("dy", ".35em")
      .style("text-anchor", "middle")
      .text(function(d) { return d.name; });

})

</script>

Modified http://d3js.org/d3.v3.min.js to a secure url

https://d3js.org/d3.v3.min.js