GeoReduceGeometry - script and chart function

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.

Syntax:

GeoReduceGeometry(field_name[, value])

Return data type: string

Arguments:

Argument	Description
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.
value	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.

[MapSource]: LOAD [world.Name], [world.Point], [world.Area] FROM [lib://Downloads/world.kml] (kml, Table is [World.shp/Features]); Map: LOAD world.Name, GeoReduceGeometry(world.Area,0.5) as [ReducedArea] resident MapSource Group By world.Name;

Drop Table MapSource;

GeoAggrGeometry - script and chart function

Loading your own map data

GeoReduceGeometry - script and chart function

Feedback