Class 10 - Force

forked from sxywu's block: Metis Class 7, #1

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
  </style>
</head>

<body>
  <script>
    var width = 500;
    var height = 500;
    var radius = 5;
    var colors = d3.scaleOrdinal(d3.schemeCategory10);
    var svg = d3.select("body").append("svg")
      .attr("width", width)
      .attr("height", height);
    
		d3.json('miserables.json', function(err, data) {
      var lines = svg.selectAll('line') //put this code above circles b/c want circles drawn above lines
      	.data(data.links)
      	.enter().append('line')
      	.attr('stroke', '#999');
      
			var circles = svg.selectAll('circle')
      	.data(data.nodes, function(d){return d.id})
      	.enter().append('circle')
      	.attr('r', radius)
      	.attr('fill', function(d){return colors(d.group)});
      
      // define force
      var simulation = d3.forceSimulation(data.nodes)
      	.force('center', d3.forceCenter(width / 2, height / 2))
      	.force('repulse', d3.forceManyBody())
      	.force('link', d3.forceLink(data.links).id(function(d){return d.id})) //without d.id, d3 doesn't know how to link up the source & targets (d.id is the id of the node)
      	.on('tick', function(){
          circles
            .attr('cx', function(d){return d.x})
          	.attr('cy', function(d){return d.y});
          lines.attr('x1', function(d){return d.source.x}) //d3 took the source node and turned it into an object
          	.attr('x2', function(d){return d.target.x})
          	.attr('y1', function(d){return d.source.y})
          	.attr('y2', function(d){return d.target.y});
        });
      
    });
  </script>
</body>

https://d3js.org/d3.v4.min.js