initialize(target) {
    if (this.type === "p" || this.type === "P" || this.type === "polar") {
      const polar2d = new Polar2D(
        this.normalizeVelocity(this.rPan.getValue()),
        this.thaPan.getValue() * MathUtil.PI_180
      );

      target.v.x = polar2d.getX();
      target.v.y = polar2d.getY();
    } else {
      target.v.x = this.normalizeVelocity(this.rPan.getValue());
      target.v.y = this.normalizeVelocity(this.thaPan.getValue());
    }
  }
Initializes the particle's velocity.
@param {object} target - The particle to initialize.