欧拉法是常微分方程的数值解法的一种，其基本思想是迭代。其中分为前进的EULER法、后退的EULER法、改进的EULER法。所谓迭代，就是逐次替代，最后求出所要求的解，并达到一定的精度。误差可以很容易地计算出来。(Euler method is a kind of numerical solution of ordinary differential equations, and its basic idea is iteration. It is divided into forward EULER method, EULER method, and improved EULER method. The so-called iteration is the successive substitution, and finally the required solution is obtained and the accuracy is achieved. The error can be easily calculated.)