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I love working with the PostGIS API. It is a deep and wide river to swim in. But sometime having read, researched, experimented, and not found the right solution one can be forced to roll one’s own so to speak to get the job done. For the problem below, if someone can point out aRead More
ESRI hosts a set of community created, domain-specific, data models on its website. As I understand the licensing of these data models, they are effectively free and open source. I have converted some of these data models into a form that they can be used natively in any of the current spatially enables databases egRead More
While there is always a need for software like Safe Software’s Awesome FME to automate import and export tasks from your database, the ability to do so just using Oracle can also be enormously useful. I have implemented the approach described below many times over the years, in different customer sites. At one customer site,Read More
The Java Topology Suite (JTS) has a linestring densifier function that is available in my Spatial Companion for Oracle (SC4O) solution. See here for documentation. For those who aren’t able to install SC4O (some DBAs don’t like it), there was a PL/SQL function in my the old GEOM Package implemetation on this website that allowsRead More
Previously I created the following Java stored procedures to enable the import/export of ZM aware WKT. ST_GeomFromText ST_GeomFromEWKT ST_AsText ST_AsEWKT These functions are necessary if one wishes to exchange geometry data with users of other databases that support WKT functions for 2D, 3D or 4D (ZM). For example, PostGIS supports the EWKT format and providesRead More
The Spatial Companion 4 Oracle (SC4O) package (built using Java Topology Suite components) contains a method called ST_PolygonBuilder that can then form polygons from linestrings. However, ST_PolygonBuilder will not form polygons where it detects an unformed intersection: in this situation ST_PolygonBuilder has to be used with another SC4O method called ST_NodeLinestrings. ST_NodeLinestrings forms all intersectionsRead More
Recently I was looking at some cadastral data with a view to working out how to polygonize the linestrings. The data contains this sort of boundary understood anomaly. To be able to able to form intersections between the cadastral boundaries and the road frontage I need to be “extend” the linestrings along the direction ofRead More
This page documents the changes made to all my Open Source Spatial Database Scripts.