D3 Examples - One Laptop Per Child #D3makeover

One Laptop Per Child #D3makeover
WORK IN PROGRESS
Attempt for #d3makeover, presenting data on how many laptops from the One Laptop Per Child (OLPC) project are present in each country.
Code based on djjupa's block: World Map of trust, which I updated to D4 v 4, and includes d3.zoom, with zoom.translateExtent. Also includes d3-tip, based on Micah Stubbs' example.
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<!DOCTYPE html>
<meta charset="utf-8">
<style>
  
  body {
    font-family: sans-serif;
  }
  
  h1, a {
    color: darkturquoise;
  }
  
  .legend {
    font-size: 12px;
  }
  
  .sea {
    fill: black;
  }
​
  .land {
    fill: #999999;
    opacity: .5;
  }
​
  .boundary {
    fill: none;
    stroke: lightgrey;
    stroke-linejoin: round;
    stroke-linecap: round;
  }
  
  circle {
    opacity: 0.5;
    fill: turquoise;
    stroke: darkturquoise;
    cursor: pointer;
  }
  
  circle:hover {
    opacity: 0.8;
  }
  
  /* Tooltip CSS */
  .d3-tip {
    line-height: 1.5;
    font-weight: 400;
    font-family: sans-serif;
    padding: 6px;
    background: rgba(0, 0, 0, 0.9);
    color: #FFA500;
    border-color: turquoise;
    border-width: turquoise;
    border-radius: 1px;
    pointer-events: none;
  }
​
  /* Creates a small triangle extender for the tooltip */
  .d3-tip:after {      
    box-sizing: border-box;
    display: inline;
    font-size: 8px;
    width: 100%;
    line-height: 1.5;
    color: rgba(0, 0, 0, 0.6);
    position: absolute;
    pointer-events: none;
    
  }
​
  /* Northward tooltips */
  .d3-tip.n:after {
    content: "\25BC";
    margin: -1px 0 0 0;
    top: 100%;
    left: 0;
    text-align: center;
  }
​
  /* Eastward tooltips */
  .d3-tip.e:after {
    content: "\25C0";
    margin: -4px 0 0 0;
    top: 50%;
    left: -8px;
  }
​
  /* Southward tooltips */
  .d3-tip.s:after {
    content: "\25B2";
    margin: 0 0 1px 0;
    top: -8px;
    left: 0;
    text-align: center;
  }
​
  /* Westward tooltips */
  .d3-tip.w:after {
    content: "\25B6";
    margin: -4px 0 0 -1px;
    top: 50%;
    left: 100%;
  }
​
</style>
​
<script src="https://d3js.org/d3.v4.min.js"></script>
<script src="https://d3js.org/topojson.v1.min.js"></script>
<script src="d3-tip.js"></script>
<body>
  <h1>One Laptop Per Child (#D3makeover)</h1>
  <p>The circles represent the number of laptops from the One Laptop Per Child (OLPC) project are present in each country, per capita.</p>
  <div id="map"></div>
  <p>Legend (laptops per capita):</p>
  <div id="legend"></div>
  <p>Source: <a href="https://one.laptop.org/map">One Laptop Per Child</a></p>
<script>
 
const format = d3.format(',');
  
const tip = d3.tip()
  .attr('class', 'd3-tip')
  .offset([0, -10])
  .html(function(d){
    return "<strong>Country: </strong><span class='details'>" + d.country
      + "<br></span><strong>Laptop per capita: </strong><span class='details'>" + roundNumber(d.percapita) + "</span>"
    + "<br></span><strong>Total laptops: </strong><span class='details'>" + format(d.count) + "</span>";
  });
  
​
var width = 900,
    height = 500;
​
var projection = d3.geoEquirectangular()
    .translate([width / 2, height / 2])
    .scale(width / 2 / Math.PI);
​
var zoom = d3.zoom()
  .scaleExtent([1, 8])
  .translateExtent([[0,0],[width,height]])
  .on("zoom", zoomed); 
 
var path = d3.geoPath()
  .projection(projection);
​
var svg = d3.select("#map").append("svg")
  .attr("width", width)
  .attr("height", height);
  
svg.call(tip);
​
var g = svg.append("g").attr("class","map").call(zoom);
  
g.append("rect")
  .attr("class", "sea")
  .attr("x",0)
  .attr("y",0)
  .attr("width",width)
  .attr("height",height);
​
d3.json("world-50m.json", function(error, world) {
  
  g.append("path")
    .datum(topojson.feature(world, world.objects.countries))
    .attr("class", "land")
    .attr("d", path);
​
  g.append("path")
    .datum(topojson.mesh(world, world.objects.countries, function(a, b) { return a !== b; }))
    .attr("class", "boundary")
    .attr("d", path);
      
  d3.csv("olpc.csv", convertTextToNumbers, function(error, data) {
    
    data.sort(function (a,b) {return d3.descending(a.percapita, b.percapita); });
    
    var radius = d3.scaleSqrt()
    .domain([0,d3.max(data, function(d){ return d.percapita; })])
    .range([5,30]);
    
    var circles = g.append("g").attr("class","circles");
        
    circles.selectAll("circle")
        .data(data)
        .enter()
      .append("circle")
      .attr("cx", function(d){ 
        return projection([d.longitude, d.latitude])[0]; 
        })
      .attr("cy", function(d){ 
        return projection([d.longitude, d.latitude])[1]; 
        })
      .attr("r", function(d){ return radius(d.percapita); })
      .on('mouseover', function(d){
        tip.direction('w').show(d);
        d3.select(this).style('stroke-width', 3);
      })
      .on('mouseout', function(d){
        tip.hide(d);
        d3.select(this).style('stroke-width',0.3);
      });
        
    var legendWidth = 400;
    var legendHeight = 75;
    var legendData = [1,10,50,100,200];
    var legendDataLength = legendData.length;
    var legendOffset = 10;
    
    var legend = d3.select("#legend").append("svg")
      .attr("width", legendWidth)
      .attr("height", legendHeight);
    
     var legendCircles = legend.selectAll("circle")
      .data(legendData)
      .enter()
        .append("g")
        .attr("transform", function(d,i) {
        let j = 0;
        var x = (legendOffset * (1 + i));
        for (j; j < i; j++ ){
          x = x + (2 * radius(legendData[j]));
        };
        return "translate(" + x + "," + (legendHeight/2) + ")"; 
      });
    
    legendCircles.append("circle")
      .attr("cx", 0)
      .attr("cy", 0)
      .attr("r", function(d){ return radius(d); });
    
    legendCircles.append("text")
        .text(function(d){return d;})
        .attr("class", "legend")
      .attr("x", 0)
      .attr("y", "0.35em")
        .style("text-anchor", "middle")
      .style("fill", "#000")
  
  });
  
});
​
  function zoomed() {
    var transform = d3.zoomTransform(this);
    g.attr("transform", "translate(" + transform.x + "," + transform.y + ") scale(" + transform.k + ")");
  };
  
  
  function roundNumber(n){
    const precision = 1000;
    var roundedNumber = Math.round(n*precision);
    return roundedNumber/precision;
  };
  
  function convertTextToNumbers(d) {
    d.count = +d.count;
    d.pop = +d.pop;
    d.percapita = +d.percapita;
    return d;
  };
​
</script>
    