Aggregation and Combination

  • Alastair Aitchison


In this Chapter, we’ll look at various ways of combining spatial data. This could be, for example, collating a column of Points together into a single MultiPoint geometry (using UnionAggregate()) or joining two touching LineStrings together into a single LineString (using STUnion()). Combinations do not have to be additive; you can also, for example, subtract the area of space occupied by one Polygon from another, using STDifference(), or obtain the unique parts of two geometries using STSymDifference(). The common feature of all the methods discussed in this Chapter is that they take two or more inputs and combine them in some way to produce a single output.


Spatial Data British Isle Symmetric Difference Unique Part Weather Radar 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Alastair Aitchison 2012

Authors and Affiliations

  • Alastair Aitchison

There are no affiliations available

Personalised recommendations