已知型值点反求控制点，最后获得B样条曲线-Data points are known to reverse the control point, and finally obtain B-spline curve

通过四重节点办法算出控制点坐标，根据控制点拟合通过型值点的3次B样条曲线(The coordinate of control points is calculated by four nodes method, and the 3 B spline curve of the control point is fitted through the value point of the type)