在工程技术领域内,经常会遇到两类典型的问题。第一类问题是研究对象称为离散系统。离散系统是可解的,但是求解复杂的离散系统需要依靠计算机技术。第二类问题是研究对象称为连续系统。在求解过程中可以建立描述连续系统的基本方程和边界条件,通常只能得到少数问题的解析解。对于大量实际工程问题,需要近似算法求解。在寻找近似解法的过程中,工程师和数学家从两个不同的路线得到了相同的 In the field of engineering technology, two types of typical problems are often encountered. The first type of problem is that the research object is called a discrete system. Discrete systems are solvable, but solving complex discrete systems requires computer technology. The second type of problem is that the research object is called continuous system. In the process of solving, the basic equations and boundary conditions describing the continuous system can be established, and usually only analytical solutions of a few problems can be obtained. For a large number of practical engineering problems, an approximate algorithm is required. In searching for approximate solutions, engineers and mathematicians got the same from two different routes