function Velocity(rpan, thapan, type) {
      var _this;
      _this = _Initialize.call(this) || this;
      _this.rPan = void 0;
      _this.thaPan = void 0;
      _this.name = void 0;
      _this.rPan = Span.setSpanValue(rpan);
      _this.thaPan = Span.setSpanValue(thapan);
      _this.type = Util.initValue(type, "vector");
      _this.name = "Velocity";
      return _this;
    }
Creates a new Velocity instance.
@param {number|Span} [rpan] - The radial component of the velocity or its range.
@param {number|Span} [thapan] - The angular component of the velocity or its range.
@param {string} [type='vector'] - The type of velocity ('vector' or 'polar').