Similar Makefile to create the ok-counties.json as the previous example. Updated the ok-counties.json with name, fips as id, and area. Uses CitySDK to retrieve county level data for the state of Oklahoma. We use that data to construct a map to then style the county with the appropriately scaled color.
Please change the API key from the census bureau if you're forking. Thanks.
| <!DOCTYPE html> | |
| <meta charset="utf-8"> | |
| <style> | |
| .county { | |
| fill: #eee; | |
| } | |
| .county-border { | |
| fill: none; | |
| stroke: #fff; | |
| } | |
| .state-border { | |
| fill: none; | |
| stroke: #333; | |
| } | |
| .caption { | |
| font-weight: bold; | |
| } | |
| .key path { | |
| display: none; | |
| } | |
| .key line { | |
| stroke: #000; | |
| shape-rendering: crispEdges; | |
| } | |
| svg { | |
| display: block; | |
| margin: auto; | |
| font: 10px sans-serif; | |
| } | |
| body { | |
| margin: 0; | |
| } | |
| @-webkit-keyframes rotate-infinite { | |
| 0% { | |
| -webkit-transform: rotate(0deg); | |
| } | |
| 100% { | |
| -webkit-transform: rotate(360deg); | |
| } | |
| } | |
| .loading-spinner { | |
| position: absolute; | |
| display: block; | |
| margin: auto; | |
| width: 100%; | |
| margin: auto; | |
| text-align: center; | |
| top: 40%; | |
| } | |
| .loading-spinner::after { | |
| content: ""; | |
| -webkit-animation: rotate-infinite .8s linear infinite; | |
| border: 5px solid #99d8c9; | |
| border-right-color: transparent; | |
| border-radius: 50%; | |
| display: inline-block; | |
| height: 50px; | |
| width: 50px; | |
| } | |
| </style> | |
| <body> | |
| <script src="//d3js.org/d3.v3.min.js"></script> | |
| <script src="//d3js.org/topojson.v1.min.js"></script> | |
| <script src="//code.jquery.com/jquery-1.11.3.min.js"></script> | |
| <script src="//cdn.rawgit.com/uscensusbureau/citysdk/Release1.1/js/citysdk.js"></script> | |
| <script src="//cdn.rawgit.com/uscensusbureau/citysdk/Release1.1/js/citysdk.census.js"></script> | |
| <script> | |
| d3.select('body') | |
| .append('div') | |
| .attr('class', 'loading-spinner'); | |
| var width = 960; | |
| var height = 500; | |
| var path = d3.geo.path() | |
| .projection(null); | |
| var svg = d3.select("body").append("svg") | |
| .attr("width", width) | |
| .attr("height", height); | |
| d3.json("ok-counties.json", function(error, ok) { | |
| if (error) throw error; | |
| var counties = topojson.feature(ok, ok.objects.counties); | |
| svg.append("g") | |
| .attr("class", "counties") | |
| .selectAll("path") | |
| .data(counties.features, function(d) { return d.id; }) | |
| .enter() | |
| .append("path") | |
| .attr('class', 'county') | |
| .attr("d", path); | |
| svg.append("path") | |
| .datum(topojson.mesh(ok, ok.objects.counties, function(a, b) { return a !== b; })) | |
| .attr("class", "county-border") | |
| .attr("d", path); | |
| svg.append("path") | |
| .datum(topojson.mesh(ok, ok.objects.counties, function(a, b) { return a === b; })) | |
| .attr("class", "state-border") | |
| .attr("d", path); | |
| }); | |
| var variableByFIPS = d3.map(); | |
| var color = d3.scale.threshold() | |
| .domain([0, 20, 75, 200, 500]) | |
| .range( ["#edf8fb", "#ccece6", "#99d8c9", "#66c2a4", "#2ca25f", "#006d2c"] ); | |
| // A position encoding for the key only. | |
| var x = d3.scale.linear() | |
| .domain([0, 600]) | |
| .range([0, 240]); | |
| var xAxis = d3.svg.axis() | |
| .scale(x) | |
| .orient("bottom") | |
| .tickSize(13) | |
| .tickValues(color.domain()); | |
| var g = svg.append("g") | |
| .attr("class", "key") | |
| .attr("transform", "translate(20,200)"); | |
| g.selectAll("rect") | |
| .data(color.range().map(function(d, i) { | |
| return { | |
| x0: i ? x(color.domain()[i - 1]) : x.range()[0], | |
| x1: i < color.domain().length ? x(color.domain()[i]) : x.range()[1], | |
| z: d | |
| }; | |
| })) | |
| .enter() | |
| .append("rect") | |
| .attr("height", 8) | |
| .attr("x", function(d) { return d.x0; }) | |
| .attr("width", function(d) { return d.x1 - d.x0; }) | |
| .style("fill", function(d) { return d.z; }); | |
| g.call(xAxis) | |
| .append("text") | |
| .attr("class", "caption") | |
| .attr("y", -6) | |
| .text("Population per square mile"); | |
| var sdk = new CitySDK(); | |
| var census = sdk.modules.census; | |
| census.enable("1b948e68b95a0ecf4936f0a6cf17c0e63c82d4de"); | |
| var request = { | |
| "level": "state", | |
| "state": "OK", | |
| "sublevel": true, | |
| "variables": [ | |
| "population" | |
| ] | |
| }; | |
| census.APIRequest(request, function (response) { | |
| console.log(response) | |
| response.data.forEach(function(d) { | |
| variableByFIPS.set(d.state + "" + d.county, +d.population) | |
| }); | |
| d3.select('.loading-spinner').remove(); | |
| d3.selectAll('.county') | |
| .style('fill', function(d) { return color(d.density = variableByFIPS.get(d.id) / d.properties.area ); }) | |
| .append('title') | |
| .text(function(d) { return d.properties.name + " " + d.density.toFixed(0) + "/mi²"; }); | |
| }); | |
| </script> |