text: /* ------------------------------------------------------------------------------
   *
   *  # D3.js - sunbirst diagram with zoom
   *
   *  Demo sunbirst diagram setup with interactive zoom
   *
   * ---------------------------------------------------------------------------- */
  
  
  // Setup module
  // ------------------------------
  
  var D3SunburstZoom = function() {
  
  
      //
      // Setup module components
      //
  
      // Chart
      var _sunburstZoom = function() {
          if (typeof d3 == 'undefined') {
              console.warn('Warning - d3.min.js is not loaded.');
              return;
          }
  
          // Main variables
          var element = document.getElementById('d3-sunburst-zoom'),
              width = 400,
              height = 400;
  
  
          // Initialize chart only if element exsists in the DOM
          if(element) {
  
              // Basic setup
              // ------------------------------
  
              // Define main variables
              var radius = Math.min(width, height) / 2;
  
  
  
              // Construct scales
              // ------------------------------
  
              // Horizontal
              var x = d3.scale.linear()
                  .range([0, 2 * Math.PI]);
  
              // Vertical
              var y = d3.scale.sqrt()
                  .range([0, radius]);
  
              // Colors
              var color = d3.scale.category20c();
  
  
  
              // Create chart
              // ------------------------------
  
              var svg = d3.select(element).append("svg")
                  .attr("width", width)
                  .attr("height", height)
                  .append("g")
                      .attr("transform", "translate(" + width / 2 + "," + height / 2 + ")");
  
  
  
              // Construct chart layout
              // ------------------------------
  
              // Partition layout
              var partition = d3.layout.partition()
                  .value(function(d) { return d.size; });
  
              // Arc
              var arc = d3.svg.arc()
                  .startAngle(function(d) { return Math.max(0, Math.min(2 * Math.PI, x(d.x))); })
                  .endAngle(function(d) { return Math.max(0, Math.min(2 * Math.PI, x(d.x + d.dx))); })
                  .innerRadius(function(d) { return Math.max(0, y(d.y)); })
                  .outerRadius(function(d) { return Math.max(0, y(d.y + d.dy)); });
  
  
  
              // Load data
              // ------------------------------
  
              d3.json("../../../../global_assets/demo_data/d3/sunburst/sunburst_basic.json", function(error, root) {
  
                  // Append sunbirst
                  var path = svg.selectAll(".d3-sunbirst")
                      .data(partition.nodes(root))
                      .enter()
                      .append("path")
                          .attr("class", "d3-sunbirst")
                          .attr("d", arc)
                          .style("fill", function(d) { return color((d.children ? d : d.parent).name); })
                          .on("click", click);
  
                  // Run transition on click
                  function click(d) {
                      path.transition()
                          .duration(750)
                          .attrTween("d", arcTween(d));
                  }
              });
  
  
              // Interpolate the scales
              function arcTween(d) {
                  var xd = d3.interpolate(x.domain(), [d.x, d.x + d.dx]),
                  yd = d3.interpolate(y.domain(), [d.y, 1]),
                  yr = d3.interpolate(y.range(), [d.y ? 20 : 0, radius]);
                  return function(d, i) {
                      return i
                      ? function(t) { return arc(d); }
                      : function(t) { x.domain(xd(t)); y.domain(yd(t)).range(yr(t)); return arc(d); };
                  };
              }
          }
      };
  
  
      //
      // Return objects assigned to module
      //
  
      return {
          init: function() {
              _sunburstZoom();
          }
      }
  }();
  
  
  // Initialize module
  // ------------------------------
  
  document.addEventListener('DOMContentLoaded', function() {
      D3SunburstZoom.init();
  });
  