Yet another animated choropleth map ...

Map demonstrates using D3.js to draw a world choropleth map and sequence through data of hypothetical timestamps.

forked from rgdonohue's block: Yet another animated choropleth map ...

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <title>d3 choropleth map</title>
    <style>
      #wrapper {
          width: 960px;
          margin: -30px auto 0;
      }
      #map {
          width: 960px;
          height: 580px;
          position: relative;
      }
      .stroke {
        fill: none;
        stroke: #888;
        stroke-width: 2px;
      }
      
      .fill {
        fill: #fff;
      }
      
      .graticule {
        fill: none;
        stroke: #777;
        stroke-width: .5px;
        stroke-opacity: .5;
      }
      
      .land {
        fill: #222;
      }
      
      .boundary {
        fill: none;
        stroke: #fff;
        stroke-width: .5px;
      }
      .country {
          fill: steelblue;
          stroke: white;
      }
      #play, #clock {
      	position: absolute;
      	top: 15px;
      }
      #play {
      	left: 15px;
      }
      #clock {
      	left: 65px;
      }
    </style>
</head>

<body>

function init() {

setMap();
  animateMap();

}

function setMap() {

width = 960, height = 580;  // map width and height, matches

projection = d3.geo.eckert5()   // define our projection with parameters
    .scale(170)
    .translate([width / 2, height / 2])
    .precision(.1);

path = d3.geo.path()  // create path generator function
      .projection(projection);  // add our define projection to it

graticule = d3.geo.graticule(); // create a graticule

svg = d3.select("#map").append("svg")   // append a svg to our html div to hold our map
      .attr("width", width)
      .attr("height", height);

svg.append("defs").append("path")   // prepare some svg for outer container of svg elements
      .datum({type: "Sphere"})
      .attr("id", "sphere")
      .attr("d", path);

svg.append("use")   // use that svg to style with css
      .attr("class", "stroke")
      .attr("xlink:href", "#sphere");

svg.append("path")    // use path generator to draw a graticule
      .datum(graticule)
      .attr("class", "graticule")
      .attr("d", path);

loadData();  // let's load our data next

}

function loadData() {

queue()   // queue function loads all external data files asynchronously 
    .defer(d3.json, "world-topo.json")  // our geometries
    .defer(d3.csv, "countriesRandom.csv")  // and associated data in csv file
    .await(processData);   // once all files are loaded, call the processData function passing
                           // the loaded objects as arguments
}

function processData(error,world,countryData) {
  // function accepts any errors from the queue function as first argument, then
  // each data object in the order of chained defer() methods above

function drawMap(world) {

svg.selectAll(".country")   // select country objects (which don't exist yet)
      .data(topojson.feature(world, world.objects.countries).features)  // bind data to these non-existent objects
      .enter().append("path") // prepare data to be appended to paths
      .attr("class", "country") // give them a class for styling and access later
      .attr("id", function(d) { return "code_" + d.properties.id; }, true)  // give each a unique id for access later
      .attr("d", path); // create them using the svg path generator defined above

var dataRange = getDataRange(); // get the min/max values from the current year's range of data values
    d3.selectAll('.country')  // select all the countries
    .attr('fill-opacity', function(d) {
        return getColor(d.properties[attributeArray[currentAttribute]], dataRange);  // give them an opacity value based on their current value
    });
}

function sequenceMap() {
  
    var dataRange = getDataRange(); // get the min/max values from the current year's range of data values
    d3.selectAll('.country').transition()  //select all the countries and prepare for a transition to new values
      .duration(750)  // give it a smooth time period for the transition
      .attr('fill-opacity', function(d) {
        return getColor(d.properties[attributeArray[currentAttribute]], dataRange);  // the end color value
      })

}

function getColor(valueIn, valuesIn) {

var color = d3.scale.linear() // create a linear scale
    .domain([valuesIn[0],valuesIn[1]])  // input uses min and max values
    .range([.3,1]);   // output for opacity between .3 and 1 %

return color(valueIn);  // return that number to the caller
}

function getDataRange() {
  // function loops through all the data values from the current data attribute
  // and returns the min and max values

function animateMap() {

var timer;  // create timer object
  d3.select('#play')  
    .on('click', function() {  // when user clicks the play button
      if(playing == false) {  // if the map is currently playing
        timer = setInterval(function(){   // set a JS interval
          if(currentAttribute < attributeArray.length-1) {  
              currentAttribute +=1;  // increment the current attribute counter
          } else {
              currentAttribute = 0;  // or reset it to zero
          }
          sequenceMap();  // update the representation of the map 
          d3.select('#clock').html(attributeArray[currentAttribute]);  // update the clock
        }, 2000);
      
        d3.select(this).html('stop');  // change the button label to stop
        playing = true;   // change the status of the animation
      } else {    // else if is currently playing
        clearInterval(timer);   // stop the animation by clearing the interval
        d3.select(this).html('play');   // change the button label to play
        playing = false;   // change the status again
      }
  });
}

window.onload = init();  // magic starts here
  
</script>
</body>
</html>

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

Modified http://d3js.org/d3.geo.projection.v0.min.js to a secure url

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

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

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

https://d3js.org/d3.geo.projection.v0.min.js

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

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