code: function (source, target, startAngle) {
                      // Given a point we need to find the next point clockwise from the start angle
                      var i,
                          point = target[target.length - 1],
                          thisAngle,
                          bestAngleSoFar = 9999,
                          returnPoint = point;
                      for (i = 0; i < source.length; i += 1) {
                          if (source[i].x !== point.x || source[i].y !== point.y) {
                              // get the angle in degrees since start angle
                              thisAngle = 180 - (Math.atan2(source[i].x - point.x, source[i].y - point.y) * (180 / Math.PI));
                              if (thisAngle > startAngle && thisAngle < bestAngleSoFar) {
                                  returnPoint = source[i];
                                  bestAngleSoFar = thisAngle;
                              }
                          }
                      }
                      target.push(returnPoint);
                      return bestAngleSoFar;
                  }
docs: Get the position data