D3 Examples - Makeover Monday

Makeover Monday - Internet users
Makeover Monday - week 22 (http://www.makeovermonday.co.uk/data/)
Incorporates the 'glow' effect from Nadieh Bremer's Datasketch for Royal Families (http://www.datasketch.es/october/code/nadieh/)
The chart applied d3.transition() to the stdDeviation attribute on the feGaussianBlur element to affect the focus of the circles that have that filter applied to it.
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<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  
  <link href="https://fonts.googleapis.com/css?family=Work+Sans" rel="stylesheet">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <script src="https://d3js.org/d3-scale-chromatic.v1.min.js"></script>
  
  <style>
    body { margin:0;top:0;right:0;bottom:0;left:30; font-family: 'Work Sans', sans-serif; background: black }
    p, h1, li { color: white }
    .domain { display: none; }
    .tick text { fill: #808080 }
    .axis-label { fill: #808080; font-size: 12; }
    .tick line { stroke: #808080; shape-rendering: crispEdges; }
    circle { cursor: pointer }
  </style>
</head>
​
<body>
​
  <h1>Growth in internet usage between 2010 and 2015</h1>
  <p>As countries near peak internet usage, the yearly growth rate has to drop off.</p>
  <p>However, looking at lower usage countries, we can see the countries that have been improving more rapidly than their counterparts.</p>
   
  <p>Overview:</p>
  <ul>
  <li>Click the legend to focus on particular regions</li>
  <li>Circle size corresponds to countries' population</li>
  </ul>
​
  <div id="chart"></div>
​
  <script>
    
    var maxX, maxY, maxR;
 
    const x = "users_2015";
    const y = "change";
    const r = "population";
    
    const defaultStdDev = 1.5;
    const defaultOpacity = 0.8;
    
    
    const width = 500;
    const height = width;
    const margin = {"top": 50, "left": 60, "right": 200, "bottom": 50,}
    
    var colour = d3.scaleOrdinal(d3.schemeSet2);
    
    var radius = d3.scaleSqrt()
      .range([3,9])
    
    var xScale = d3.scaleLinear()
      .range([0,width]);
    
    var yScale = d3.scaleLog()
      .range([height, 0]);
     
    
    var xAxis = d3.axisBottom(xScale);
    var yAxis = d3.axisLeft(yScale)      
      .tickValues([0.01,0.1,0.5,1,10,20,40,80])
      .tickFormat(formatLog);
    
    var svg = d3.select("#chart").append("svg")
       .attr("width", width + margin.right + margin.left)
       .attr("height", height + margin.top + margin.bottom);
    
    //Container for the gradients
    var defs = svg.append("defs");
     
    d3.csv("data.csv", convertTextToNumbers, function(error, data) {
      
      if(error) { throw error; };
   
      maxX = d3.max(data, function(d){ return d[x]; });
      maxY = d3.max(data, function(d){ return d[y]; });
      maxR = d3.max(data, function(d){ return d[r]; });
      
      xScale.domain([0,100]);
      yScale.domain([0.001,maxY]);
      radius.domain([0,maxR]);
      
      //Code taken from  https://www.datasketch.es/october/code/nadieh/ and https://stackoverflow.com/questions/9630008/how-can-i-create-a-glow-around-a-rectangle-with-svg
    //Filter for the outside glow
      
    var nestByRegion = d3.nest()
        .key(function(d) { return d.regionTrimmed; })
        .entries(data);
    
    var filters = defs.selectAll("filter")
        .data(nestByRegion)
        .enter()
        .append("filter")
      .attr("width", "300%")
      .attr("x", "-100%")
      .attr("height", "300%")
      .attr("y", "-100%")
      .attr("id", function(d){ return d.key + "-glow"; })
​
    var blurs = filters.append("feGaussianBlur")
      .attr("class", "blur")
      .attr("stdDeviation", defaultStdDev)
      .attr("result", "coloredBlur");
 
      var xAxisG = svg.append("g")
        .attr("transform", "translate(" + (margin.left) + "," + (margin.top + height) + ")")
        .call(xAxis);
      
      xAxisG.append("text")
      .text("% usage in 2015")
      .attr("fill", "white")
      .attr("x", width + 10)
      .attr("y", -10)
      .style("text-anchor", "end")
      
      var yAxisG = svg.append("g")
        .attr("transform", "translate(" + (margin.left) + "," + margin.top + ")")
        .call(yAxis);
      
      yAxisG.append("text")
      .text("% growth from 2010 to 2015")
      .attr("fill", "white")
      .attr("x", -37)
      .attr("y", -15)
      .style("text-anchor", "start")
      yAxisG.selectAll(".tick").selectAll("line")
      .attr("x2", width)
      .style("opacity", 0.5)
       
      var g = svg.append("g")
      .attr("transform", "translate(" + (margin.left) + "," + margin.top + ")");
         
      var circles = g.selectAll("g")
      .data(data)
      .enter()
      .append("g")
      .attr("class", "user-circle")
      .attr("transform", function(d) { 
        return "translate(" + xScale(d[x]) + "," + yScale(d[y]) +")"; 
      })
      .attr("id", function(d,i){ return "circle-" + i }) ;
      
      circles.append("circle")
      .attr("r", function(d){ return radius(d[r]); })
      .attr("cx", 0)
      .attr("cy", 0)
      .style("fill", function(d) { return colour(d.region) })
      .style("opacity", defaultOpacity)
      .style("filter",function(d) {
        return "url(#" + d.regionTrimmed + "-glow)"
      })
      .on("mouseover", function(d){     
        circles.selectAll("text").style("opacity",0);
        d3.select(this.parentNode).select("text").style("opacity",1); 
      })
      .on("mouseout", function(d){     
        circles.selectAll("text").style("opacity",0);
      });
      
      circles.append("text")
      .text(function(d) { return d.country })
      .attr("x", 5)
      .attr("y", -5)
      .style("fill", "white")
      .style("opacity", 0)
      .style("pointer-events", "none");
      
      var legend = svg.append("g")
      .attr("transform", "translate("+(width + margin.left + 30)+",55)");
      
      var legendEntries = legend.selectAll(".legend-items")
      .data(colour.domain())
      .enter()
      .append("g")
      .attr("transform", function(d, i){
        return "translate(0," + (i * 18) + ")"
      });
            
      legendEntries.append("circle")
      .attr("r", 5)
      .attr("cx", 0)
      .attr("cy", 0)
      .style("fill", function(d) { return colour(d) })
      .style("filter",function(d) { return "url(#" + removeWhiteSpace(d) + "-glow)"; })
      .on("click", function(d){     
        
        circles.selectAll("circle")
        .attr("pointer-events", function(c) {
          return d == c.region ? "all" : "none";
        })
        .transition()
        .style("opacity",function(c) {
          return d == c.region ? 1 : 0.2;
        });
        
        blurs.transition()
          .attr("stdDeviation", function(b) {
            return b.key == removeWhiteSpace(d) ? 0.8 : 3;
            });
        
      });
​
   
      legendEntries.append("text")
      .text(function(d) { return d})
      .attr("x", 11)
      .attr("y", 5)
      .style("fill", "white");
    
      legend.append("text")
      .text("Reset")
      .attr("y", (colour.domain().length * 20))
      .attr("x", 11)
      .style("fill", "grey")
      .on("click", function(d){     
        circles.selectAll("circle")
        .style("opacity", defaultOpacity)
        .attr("pointer-events", "default");
      
        blurs.transition()
          .attr("stdDeviation", defaultStdDev);
        
      });
   
    });
     
    function convertTextToNumbers(d) { 
        
        d.regionTrimmed = removeWhiteSpace(d.region);
        d.change = +d.change;
        d.population = +d.population;
        d.users_2015 = +d.users_2015;
        d.users_2010 = +d.users_2010;
        return d;
    };
    
    function formatLog(n){
      return d3.format("0.2f")(n);
    };
    
    function removeWhiteSpace(str){
      return str.replace(/\s/g, '');
    };
     
  </script>
</body>
​
    