A north arrow — north_arrow • fancymaps

A north arrow

Usage

north_arrow(box, position = c("tr", "tl", "br", "bl"), base_size = 12)

Arguments

box: The panel extent, as a bbox in the display CRS.
position: One of "bl", "br", "tl", "tr" – which corner.
base_size: Font size for the label, in points.

Value

A list of ggplot2 layers.

Details

Grid north, not magnetic north, and not exactly true north away from the centre of the projection – in an azimuthal or transverse projection the meridians converge, so "up" is true north only along the central one. Over a regional extent the difference is a degree or two and the arrow is a reading aid rather than a navigation instrument. Over a continental extent it stops being either, which is why map_surface() draws it by default and lets you turn it off.

Examples

box <- sf::st_bbox(c(xmin = -70.5, ymin = 42.5, xmax = -68, ymax = 44.5),
                   crs = sf::st_crs(4326))
north_arrow(box)
#> [[1]]
#> mapping: x = ~x, y = ~y 
#> geom_polygon: na.rm = FALSE
#> stat_identity: na.rm = FALSE
#> position_identity 
#> 
#> [[2]]
#> mapping: x = ~x, y = ~y 
#> geom_text: na.rm = FALSE
#> stat_identity: na.rm = FALSE
#> position_identity 
#>