Table 1. Description of the spatial measures considered.

Name	Values	Description
clusteredness	[0, 1]	Indicates if regions contain holes (clusteredness <1) or not (clusteredness = 1), respectively measures if the average distance between all positions considered in a cluster is small (clusteredness →1) or large (clusteredness →0).
density	[0, 1]	Computes the average value associated with the discretised spatial positions defining a region/cluster.
area	ℝ+	Represents the number of positions in the discretised space associated with a region/cluster.
perimeter	ℝ+	Represents the length of the outer contour of a region, respectively the convex hull of a cluster.
distance from the origin	ℝ+	Computes the minimum distance between the outer contour of a region, respectively the convex hull of a cluster, and the centre point of the discretised spatial domain.
angle	[0, 360] (degrees)	Determined by the lines that pass through the discretised spatial domain’s centre point and are tangent to a region’s outer contour, respectively cluster’s convex hull.
triangle/rectangle/circle measure	[0, 1]	Indicates if the shape of the region’s outer contour, respectively cluster’s convex hull, is similar to a triangle/rectangle/circle (triangle/rectangle/circle measure →1) or not (triangle/rectangle/circle measure →0).
centroid Ox/Oy coordinate	ℝ+	Represents the Ox/Oy coordinate of the geometric centre of the region’s outer contour, respectively cluster’s convex hull.

Each spatial measure considered has a name (column “Name”), an associated range of valid values (column “Values”) and a corresponding description (column “Description”). In case of spatial measures which have similar semantics the table rows have been merged and the spatial measure names are separated by the “/” symbol (see last two table rows).