Calculate approximate map scale
an_mapscale(map_dimensions, map_extent)
map_dimensions | numeric: 2-element numeric giving width and height of the map, in mm |
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map_extent | vector of c(longitude_min, longitude_max, latitude_min, latitude_max): the geographic extent of the map. |
numeric
## an A3-sized map of the Southern Ocean (1:20M) an_mapscale(map_dimensions = c(400, 570), map_extent = c(-180, 180, -90, -40))#> [1] 19967274