Electron Answer

_.md

[ Launch: Electron Setup ] 5621566 by lewis500

config.json

{"endpoint":"","display":"svg","public":true,"require":[],"tab":"edit","display_percent":0.7,"play":false,"loop":false,"restart":false,"autoinit":true,"pause":true,"loop_type":"period","bv":false,"nclones":15,"clone_opacity":0.4,"duration":3000,"ease":"linear","dt":0.01,"description":"Electron Answer","fileconfigs":{"config.json":{"default":true,"vim":false,"emacs":false,"fontSize":12},"inlet.js":{"default":true,"vim":false,"emacs":false,"fontSize":12},"_.md":{"default":true,"vim":false,"emacs":false,"fontSize":12}},"fullscreen":false,"thumbnail":"http://i.imgur.com/7t9HmVM.png"}

inlet.js

var svg = d3.select("svg");

var cx = tributary.sw/2;
var cy = tributary.sh/2;
var radius = 200;

var outer = svg.append("circle")
    .attr({
      cx: cx,
      cy: cy,
      r: radius,
      fill: "none",
      stroke: "#1B8600",
      "stroke-width": 4
    });

var electron = svg.append("circle")
    .attr({
      cx: cx + radius,
      cy: cy,
      r: 15,
      fill: "#067BA8"
    });

var drag = d3.behavior.drag()
    .on("drag", function() {
      var mx = d3.mouse(this)[0] - cx;
      var my = d3.mouse(this)[1] - cy;
      
      var angle = Math.atan2(my, mx);
      var nx = radius * Math.cos(angle) + cx;
      var ny = radius * Math.sin(angle) + cy;
      
      electron.attr({
        cx: nx,
        cy: ny
      })
      
    })

electron.call(drag);