我有一个在PostGis数据库中存储和空间索引的实体E的空间分布集合。有效的查询来定位postgis中簇的质心?
每个实体具有多个索引非空间属性,诸如类型,值等
的是否有以下类型的查询的计算上高效的查询模板:
"find the centroid of the circular region with radius X which includes the most E such that (some condition based on attribue values)"
例如
"find the centroid of the circular region with radius 1Km which contains the most E with TYPE == 'PIZZA-RESTAURANT'"
谢谢!
您可能会在姊妹站点获得更好的答案:http://gis.stackexchange.com/ – 2011-04-26 10:48:08