Abstract: Techniques in a data processor for drawing a density surface on a map in a manner that more accurately accounts for projection distortion in the map. According to one embodiment, data is maintained that represents a geotagged event. A map plane is divided into a plurality of cells and an origin cell corresponding to the geotagged event is identified. Density values are allocated to cells surrounding the origin cell based on geodetic distances between geographic coordinates corresponding to surrounding cells and the geographic coordinate of the geotagged event. A density surface based on the cell allocations is then displayed on a map. By allocating density values to cells based on geodetic distances, the resulting density surface displayed on the map more accurately accounts for projection distortions in the area of the map on which density surface is displayed.

Abstract: Techniques in a data processor for drawing on a map a geodetic polygon that straddles a splitting meridian include, in one embodiment, maintaining data that represents the geodetic polygon, the data comprising a set of geographic coordinates; transforming the set of geographic coordinates into a set of planar coordinates representing a planar polygon; splitting the planar polygon into a plurality of sub-figures; shifting at least one sub-figure of the plurality of sub-figures along a horizontal axis of two-dimensional plane to produce a shifted sub-figure; and causing the shifted sub-figure to be displayed on a map concurrently with at least one other sub-figure of the plurality of sub-figures that was not shifted.