# Break antimeridian for plotting not centred on Greenwich

Source:`R/break_antimeridian.R`

`st_break_antimeridian.Rd`

Longitudes can be broken at the antimeridian of a target central longitude
to permit plotting of (usually world) line or polygon objects centred
on the chosen central longitude. The method may only be used with
non-projected, geographical coordinates and linestring or polygon objects.
s2 is turned off internally to permit the use of a rectangular bounding
box. If the input geometries go outside `[-180, 180]`

degrees longitude,
the protruding geometries will also be split using the same `tol=`

values; in this case empty geometries will be dropped first.

## Usage

```
st_break_antimeridian(x, lon_0 = 0, tol = 1e-04, ...)
# S3 method for class 'sf'
st_break_antimeridian(x, lon_0 = 0, tol = 1e-04, ...)
# S3 method for class 'sfc'
st_break_antimeridian(x, lon_0 = 0, tol = 1e-04, ...)
```

## Examples

```
# \donttest{
if (require("maps", quietly=TRUE)) {
opar = par(mfrow=c(3, 2))
wld = st_as_sf(map(fill=FALSE, interior=FALSE, plot=FALSE), fill=FALSE)
for (lon_0 in c(-170, -90, -10, 10, 90, 170)) {
wld |> st_break_antimeridian(lon_0=lon_0) |>
st_transform(paste0("+proj=natearth +lon_0=", lon_0)) |>
st_geometry() |> plot(main=lon_0)
}
par(opar)
}
#> Warning: st_break_antimeridian: longitude coordinates outside [-180, 180]
#> Spherical geometry (s2) switched off
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> Spherical geometry (s2) switched on
#> Spherical geometry (s2) switched off
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> Spherical geometry (s2) switched on
#> Warning: st_break_antimeridian: longitude coordinates outside [-180, 180]
#> Spherical geometry (s2) switched off
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> Spherical geometry (s2) switched on
#> Spherical geometry (s2) switched off
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> Spherical geometry (s2) switched on
#> Warning: st_break_antimeridian: longitude coordinates outside [-180, 180]
#> Spherical geometry (s2) switched off
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> Spherical geometry (s2) switched on
#> Spherical geometry (s2) switched off
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> Spherical geometry (s2) switched on
#> Warning: st_break_antimeridian: longitude coordinates outside [-180, 180]
#> Spherical geometry (s2) switched off
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> Spherical geometry (s2) switched on
#> Spherical geometry (s2) switched off
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> Spherical geometry (s2) switched on
#> Warning: st_break_antimeridian: longitude coordinates outside [-180, 180]
#> Spherical geometry (s2) switched off
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> Spherical geometry (s2) switched on
#> Spherical geometry (s2) switched off
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> Spherical geometry (s2) switched on
#> Warning: st_break_antimeridian: longitude coordinates outside [-180, 180]
#> Spherical geometry (s2) switched off
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> Spherical geometry (s2) switched on
#> Spherical geometry (s2) switched off
#> although coordinates are longitude/latitude, st_intersection assumes that they
#> are planar
#> Warning: attribute variables are assumed to be spatially constant throughout all geometries
#> Spherical geometry (s2) switched on
# }
```