ol-ext: HexBin source
Hexagonal binning is a convenient way for aggregating data into a coarser representation for display.
In an hexbin map (hexagonal heatmap) features are scattered on hexagons.
Hexbins can support a color encoding or point encoding.
You can use the color, density of the hexagon or its size to display
the value of the features aggregated in the hexagon.
ol.source.HexBin is a ol.source.Vector, similar to a ol.source.Cluster
ol.source.ImageHexBin is a ol.source.ImageVector, more efficient to use with large data sets.
HexBin use a ol.HexGrid to compute hexagonal grid.
For more information on hexgrid metrics, see
the Hexmap example.