Application of Delaunay Triangulation and Inverse Distance Weighting (IDW) in Oracle for Soils Interpolation. Monday March 19 2012 at 00:01 The need to be able to create and use Delaunay triangles (or voronoi diagrams) inside a database is something not often heard. In addition, neither is Z interpolation of grid cell values using Delaunay triangles in consort with an Inverse Distance Weighted (IDW) algorithm.
“Why would you want to?” Is a common cry. And, for many years I would have agreed with you but recently two things intersected in a most unexpected way. 1. In the SC4O project, I decided to expose JTS’s ability to create Delaunay triangles (and Voronoi cells) from a set of input vertices (I have seen talk of the need for this in the PostGIS discussion list but no solution, integrated into the PostGIS API is yet available). An example of some sample points being turned into a set of Delaunay triangles can be seen here: 2. The field, and values observed at each sample point (I only include 4 out of all the variables: Potassium, Phosphorus, Ph and Sodium) are shown in the following diagram.
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