龙贝格算法实现，并通过具体实例函数进行说明。可以自己修改实例函数，并设置积分下限、积分上限、积分结束精度、运算最大次数等参量。-Romberg algorithm, and illustrated by specific examples of functions. You can modify their own instance of the function and set the lower limit of integration, integration limit, precisi