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Create a graticule

graticule.Rd

Create a graticule. That is, a grid of lon/lat lines that can be used to on a projected map.

The object returned, a SpatGraticule, can be plotted with plot and lines. There is also a crop method.

Usage

graticule(lon=30, lat=30, crs="")

Arguments

lon

numeric. Either a single number (the interval between longitudes), or a vector with longitudes

lat

numeric. Either a single number (the interval between latitudes), or a vector with latitudes

crs

character. The coordinate reference system to use

Value

SpatGraticule

See also

plot<SpatGraticule>.

Examples

g <- graticule(60, 30, crs="+proj=robin")
g
#> class       : SpatGraticule 
#> lon         : -180 -120 -60 0 60 120 180 
#> lat         : -90 -60 -30 0 30 60 90 
#> coord. ref. : +proj=robin +lon_0=0 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs 
#> extent      : -17005833, 17005833, -8625155, 8625155  (xmin, xmax, ymin, ymax)

graticule(90, c(-90, -60, -23.5, 0, 23.5, 60, 90), crs="+proj=robin")
#> class       : SpatGraticule 
#> lon         : -180 -90 0 90 180 
#> lat         : -90 -60 -23.5 0 23.5 60 90 
#> coord. ref. : +proj=robin +lon_0=0 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs 
#> extent      : -17005833, 17005833, -8625155, 8625155  (xmin, xmax, ymin, ymax)