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Generate equal-area latitudinal bins

Source: R/lat_bins_area.R
lat_bins_area.Rd

A function to generate approximately equal-area latitudinal bins for a user-specified number of bins and latitudinal range. This approach is based on calculating the curved surface area of spherical segments bounded by two parallel discs.

Usage

lat_bins_area(n = 12, min = -90, max = 90, r = 6371, plot = FALSE)

Arguments

n

numeric. A single numeric value defining the number of equal-area latitudinal bins to split the latitudinal range into (as defined by min and max).

min

numeric. A single numeric value defining the lower limit of the latitudinal range (defaults to -90).

max

numeric. A single numeric value defining the upper limit of the latitudinal range (defaults to 90).

r

numeric. The radius of the Earth in kilometres. Defaults to the volumetric mean radius of the Earth (6371 km). Other user-specified r values are accepted (e.g. equatorial radius 6378 km).

plot

logical. Should a plot of the latitudinal bins be generated? If TRUE, a plot is generated. Defaults to FALSE.

Value

A data.frame of user-defined number of latitudinal bins. The data.frame contains the following columns: bin (bin number), min (minimum latitude of the bin), mid (midpoint latitude of the bin), max (maximum latitude of the bin), area (the area of the bin in km2), area_prop (the proportional area of the bin across all bins).

Developer(s)

Lewis A. Jones & Kilian Eichenseer

Reviewer(s)

Kilian Eichenseer & Bethany Allen

See also

For bins with unequal area, but equal latitudinal range, see lat_bins_degrees.

Examples

# Generate 12 latitudinal bins
bins <- lat_bins_area(n = 12)
# Generate latitudinal bins for just the (sub-)tropics
bins <- lat_bins_area(n = 6, min = -30, max = 30)
# Generate latitudinal bins and a plot
bins <- lat_bins_area(n = 24, plot = TRUE)