AC100 vs WS 100 - Elevation Profile

Comparison of elevation profiles for the Western States 100 (http://www.wser.org/) and Angeles Crest 100 (http://www.ac100.com/), using gpx tracks and USGS 1/3 arc-second DEMs. Difference chart derived from /mbostock/3894205.

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

body {
  font: 10px sans-serif;
}

.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

.x.axis path {
  display: none;
}

.area.above {
  fill: rgb(145,207,96);
}

.area.below {
  fill: rgb(252,141,89);
}

.legendSizeLine line {
    stroke: rgb(145,207,96);
   }

.line {
  fill: none;
  stroke: #000;
  stroke-width: 1.5px;
}

</style>
<body>
<script src="https://d3js.org/d3.v3.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3-legend/1.6.0/d3-legend.min.js""></script>
<script>

var margin = {top: 20, right: 20, bottom: 30, left: 50},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;

var x = d3.scale.linear()
    .range([0, width]);

var y = d3.scale.linear()
    .range([height, 0]);

var xAxis = d3.svg.axis()
    .scale(x)
//    .orient("bottom");

var yAxis = d3.svg.axis()
    .scale(y)
    .orient("left");

var line = d3.svg.area()
    .interpolate("linear")
    .x(function(d) { return x(d.mile); })
    .y(function(d) { return y(d["WS100"]); });

var area = d3.svg.area()
    .interpolate("linear")
    .x(function(d) { return x(d.mile); })
    .y1(function(d) { return y(d["WS100"]); });

var svg = d3.select("body").append("svg")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

//https://d3-legend.susielu.com/
var linear = d3.scale.linear()
  .domain([0,10])
  .range(["rgb(252,141,89)", "rgb(145,207,96)"]);

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

svg.append("g")
  .attr("class", "legendLinear")
  .attr("transform", "translate(20,400)");

var legendLinear = d3.legend.color()
  .shapeWidth(100)
 // .cells([1, 2]
  .cells(2)
  .orient('horizontal')
  .labels(["WS100 higher el.", "AC100 higher el."])
  .scale(linear);

svg.select(".legendLinear")
  .call(legendLinear);

d3.tsv("data.tsv", function(error, data) {
  if (error) throw error;

data.forEach(function(d) {
    d["mile"]= +d["mile"];
    d["WS100"]= +d["WS100"];
    d["AC100"] = +d["AC100"];
  });

x.domain(d3.extent(data, function(d) { return d.mile; }));

y.domain([
    d3.min(data, function(d) { return Math.min(d["WS100"], d["AC100"]); }),
    d3.max(data, function(d) { return Math.max(d["WS100"], d["AC100"]); })
  ]);

svg.datum(data);

svg.append("clipPath")
      .attr("id", "clip-below")
    .append("path")
      .attr("d", area.y0(height));

svg.append("clipPath")
      .attr("id", "clip-above")
    .append("path")
      .attr("d", area.y0(0));

svg.append("path")
      .attr("class", "area above")
      .attr("clip-path", "url(#clip-above)")
      .attr("d", area.y0(function(d) { return y(d["AC100"]); }));

svg.append("path")
      .attr("class", "area below")
      .attr("clip-path", "url(#clip-below)")
      .attr("d", area);

svg.append("path")
      .attr("class", "line")
      .attr("d", line);

svg.append("g")
      .attr("class", "y axis")
      .call(yAxis)
    .append("text")
      .attr("transform", "rotate(-90)")
      .attr("y", 6)
      .attr("dy", "-4.75em")
      .style("text-anchor", "end")
      .text("Elevation (feet)");

svg.append("g")
      .attr("class", "xaxis")
      .call(xAxis)
    .append("text")
      .attr("transform", "rotate(0)")
      .attr("x", 880)
      .attr("dx", ".95em")
      .style("text-anchor", "end")
      .text("Distance (miles)");

});

</script>
<div>Source of elevation data: <a href="https://catalog.data.gov/dataset/national-elevation-dataset-ned-1-3-arc-second-downloadable-data-collection-national-geospatial">USGS National Map (1/3 arc-second DEMs)</a></div>

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

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

https://cdnjs.cloudflare.com/ajax/libs/d3-legend/1.6.0/d3-legend.min.js