Schematic representation of a DBSCAN cluster with minPts = 3. Points in green represent core points, each point has minPts points in its (green solid) hypersphere. The blue triangle represents a member point, it does not have minPts in its (blue dashed) hypersphere but it is reached by a core point. The red square represents a field star; it does not have any other point in its (red dash-dot) hypersphere. All the hyperspheres have radius equal to ɛ.