reset(rpan, thapan, type) {
    this.rPan = Span.setSpanValue(rpan);
    this.thaPan = Span.setSpanValue(thapan);
    this.type = Util.initValue(type, "vector");
  }
Resets the velocity parameters.
@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').