基于直方图的草图技术是用于道路网的数据流聚集查询,为了说明问题，先对直方图的信息进行实例化，基于直方图的动态草图索引结构跟AMH的结构相似-we propose a dynamic sketch method by integrating sketch and histogram techniques, for aggregate queries over the network-constrained traffic data streams and build the index, to s

该代码实现将基本的地图匹配功能,讲GPS获取到的数据与路网匹配，并将偏移道路的数据拉回道路上-this python code complet function that map matching

中国路网数据，该数据对全国的路网收集较为全面，但未对道路进行分级(China's road network data, the data is more comprehensive for the country's road network, but the road is not classified)