GeoReduceGeometry() is used to reduce the number of vertices of a geometry, and to aggregate a number of areas into one area, but still displaying the boundary lines from the individual areas.
Return data type: string
|field_name||A field or expression referring to a field containing the geometry to be represented. This could be either a point (or set of points) giving longitude and latitude, or an area.|
The amount of reduction to apply to the geometry. The range is from 0 to 1, with 0 representing no reduction and 1 representing maximal reduction of vertices.
Note: Using a value of 0.9 or higher with a complex data set can reduce the number of vertices to a level where the visual representation is inaccurate.
GeoReduceGeometry() also performs a similar function to, GeoAggrGeometry() in that it aggregates a number of areas into one area. The difference being that individual boundary lines from the pre-aggregation data are displayed on the map if you use GeoReduceGeometry().
As GeoReduceGeometry() is an aggregating function, if you use it in the script a LOAD statement with a Group by clause is required.
This example loads a KML file with area data, and then loads a table with the reduced and aggregated area data.