说明：  matlab绘制世界地图，并将一些案例数据点（经纬度信息）在图中可视化标出，并通过聚类分析出五个数据中心点，用红色标记出。（聚类过程未列出，采用spss软件易得）
(Matlab draws the world map, and some case data points (longitude and latitude information) are visualized in the map, and five data center points are identified by clustering analysis, marked with red. (clustering process is not listed, easy to get if use SPSS software).)