ST_AddPoint—将点添加到LineString。 ST_CollectionExtract—给定(多)几何,返回仅由指定类型的元素组成的(多)几何。 ST_CollectionHomogenize—给定几何集合,返回内容的“最简单”表示形式。 ST_CurveToLine—将包含曲线的几何转换为线性几何。 ST_FlipCoordinates—返回X和Y轴已翻转的几何版本。 ST_Force2D—将几何...
生成格网数据的方法其实有很多,例如在之前的PostGIS中可以写一个plpgsql function根据起点,终点,cell分辨率快速生成格网等,由于格网数据比较常用,所以PostGIS3.1直接提供了ST_SquareGrid()(正方形网格)与ST_HexagonGrid()(蜂窝网格)两种格网方法。 稍微不同的是,PostGIS3.1中生成的网格是具有统一的特征的: 生成网格...
后端实现方式目前只尝试过一种:使用geotools vector grid包link ReferencedEnvelope gridBounds=newReferencedEnvelope(110.0,150.0,-45.0,-5.0,DefaultGeographicCRS.WGS84);SimpleFeatureSource grid=Grids.createSquareGrid(gridBounds,10.0); image.png 最后一种就是借助postgis,通过数据库生成 ...
integer height, boolean padwithnodata=FALSE, double precision nodataval=NULL); setof raster ST_Tile(raster rast, integer nband, integer width, integer height, boolean padwithnodata=FALSE, double precision nodataval=NULL); setof raster ST_Tile(raster rast, integer width, integer height, boole...
cursor.execute('update gps_track set geometry = ST_SetSRID(geometry,4326)') 查询是否上传成功: # Retrieve the table contents and print it cursor.execute('SELECT * FROM gps_track') forrowincursor: print(row[0]) 关闭连接: # Disconnect from the database ...
functions available, and it is hard to get past simple things like ST_Intersects and ST_DWithin to the next level.But once you get to the next level, youʼll find that PostGIS is as powerful (or more)than many desktop GIS systems.My son suggested the following topical breakdown.
In this case we left out the last sliver by making our grid not completely cover the extent of the region. Another important thing to keep in mind is that the geometry type returned by ST_Intersection may look rather different than the input geometries, but it’s guaranteed to be of ...
(POINT,4269) ); INSERT INTO ch02.my_points (p, pz, pm, pzm, p_srid) VALUES ( ST_GeomFromText('POINT(1 -1)'), ST_GeomFromText('POINT Z(1 -1 1)'), ST_GeomFromText('POINT M(1 -1 1)'), ST_GeomFromText('POINT ZM(1 -1 1 1)'), ST_GeomFromText('POINT(1 -1)',...
--Delete all polygons smaller than 1px square at zoom level 10DELETEFROMwater_polygonsWHEREsqrt(ST_Area(geom))<ZRes(10);--Simplify geometries to a resolution appropriate for zoom level 10UPDATEwater_polygonsSETgeom=ST_Simplify(geom, ZRes(10)); ...
You may instead want to use ST_SquareGrid to create a regular grid within the specified bounds. Share Improve this answer Follow answered Jan 5, 2023 at 12:31 JGH 42.6k33 gold badges4444 silver badges9090 bronze badges Add a comment 1 The concept of subdividing...