Class PointStackerProcess

  • All Implemented Interfaces:
    VectorProcess

    public class PointStackerProcess
    extends Object
    implements VectorProcess
    A Rendering Transformation process which aggregates features into a set of visually non-conflicting point features. The created points have attributes which provide the total number of points aggregated, as well as the number of unique point locations.

    This is sometimes called "point clustering". The term stacking is used instead, since clustering has multiple meanings in geospatial processing - it is also used to mean identifying groups defined by point proximity.

    The stacking is defined by specifying a grid to aggregate to. The grid cell size is specified in pixels relative to the requested output image size. This makes it more intuitive to pick an appropriate grid size, and ensures that the aggregation works at all zoom levels.

    The output is a FeatureCollection containing the following attributes:

    • geom - the point representing the cluster
    • count - the total number of points in the cluster
    • countunique - the number of unique point locations in the cluster
    Note that as required by the Rendering Transformation API, the output has the CRS of the input data.
    Author:
    mdavis, Cosmin Cioranu (CozC)