dragging demo

Drag things

by nancynancy

HTML

<script src="https://d3js.org/d3.v4.min.js"></script>
<script src="https://d3js.org/d3-hexbin.v0.2.min.js"></script>
<pre id="data">
A,B
3,2.1
3,3.2
1,2.3
5,5.4
5,1.5
3,5.6
4,4.7
2,2.8
1,2.9
3,4.1
4,2.2
1,3.3
2,5.4
3,2.5
4,1.6
</pre>

CSS

.active {
  stroke: #000;
  stroke-width: 2px;
}


pre {
  display:none;
  }

JavaScript

var margin = {top: 20, right: 20, bottom: 20, left: 40};        
var width = 300 - margin.left - margin.right;
var height = 300 - margin.top - margin.bottom;
var radius = 30;
var hexbin = d3.hexbin().radius(radius);
var x = d3.scaleLinear().range([0, width])
var y = d3.scaleLinear().range([height, 0])
var color = d3.scaleOrdinal().range(d3.schemeCategory20);
var data = d3.csvParse(d3.select("pre#data").text());
dataPoints = [];

x.domain(d3.extent(data, function(d) { return d.A; })).nice();
y.domain(d3.extent(data, function(d) { return d.B; })).nice();

data.forEach(function(d){
		d.A = +d.A;
   	d.B = +d.B;
    dataPoints.push([x(d.A), y(d.B)]);
});

var force = d3.layout.force()
    .gravity(0.07)
    .charge(function(d, i) { return i ? 0 : -2000; })
    .nodes(data)
    .size([width, height]);

force.start();

var svg = d3.select("body").append("svg")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
    
force.on("tick", function(e) {
  var q = d3.geom.quadtree(data),
      i = 0,
      n = data.length;

while (++i < n) q.visit(collide(data[i]));


svg.on("mousemove", function() {
  var p1 = d3.mouse(this);
  root.px = p1[0];
  root.py = p1[1];
  force.resume();
});

function collide(node) {
  var r = node.radius + 16,
      nx1 = node.x - r,
      nx2 = node.x + r,
      ny1 = node.y - r,
      ny2 = node.y + r;
  return function(quad, x1, y1, x2, y2) {
    if (quad.point && (quad.point !== node)) {
      var x = node.x - quad.point.x,
          y = node.y - quad.point.y,
          l = Math.sqrt(x * x + y * y),
          r = node.radius + quad.point.radius;
      if (l < r) {
        l = (l - r) / l * .5;
        node.x -= x *= l;
        node.y -= y *= l;
        quad.point.x += x;
        quad.point.y += y;
      }
    }
    return x1 > nx2 || x2 < nx1 || y1 > ny2 || y2 < ny1;
  };
};

    
svg.append("g")
    .attr("clip-path", "url(#clip)")
    .selectAll(".hexagon")
   ...