geo_select_aeq          Azimuthal Equidistant Projection
london_area             Region representing London in projected
                        coordinate system
zb_100_triangular_numbers
                        The first 100 triangular numbers
zb_color                Generate colors for zones
zb_doughnut             Make doughnuts
zb_lines                Create lines radiating at equal angles from a
                        point
zb_plot                 Plot zones
zb_quadrat              Divide a region into quadrats
zb_segment              Make segments
zb_zone                 Generate zones covering a region of interest
