里面有两个功能函数fun1、fun2，最后在xianxingqiehuan1这个M文件里调用函数，初值确定的情况下实现了两个功能函数fun1和fun2轮流运行相同时间不断在彼此间切换的功能-There are two functions function fun1, fun2, finally calling the function M in xianxingqiehuan1 this document, the case of the initial implementation of the two functions to determine the function fun1 and fun2 take turns running the same time constantly switching function between each other