说明：  dijkstra算法的matlab程序，用于优化路径规划的初始路径，只能做出一个次优的结果，以后可以用很多优化算法来进一步优化
(dijkstra the algorithm matlab procedure, uses in to optimize the way plan the initial way, only can make an order superior result, later will be allowed to use the very many optimized algorithm further to optimize )