Standardise longitude values to a selected prime meridian convention

Converts longitude values to either the `[-180, 180]` convention or the `[0, 360]` convention.

Usage

checkLongitude(x, primeMeridian = "center", sort = FALSE, ...)

Arguments

x

Numeric vector of longitude values.

primeMeridian

Character string specifying the target longitude convention. Use `"center"` for longitudes in the `[-180, 180]` range and `"left"` for longitudes in the `[0, 360]` range.

sort

Logical. If `TRUE`, sort the output values after conversion.

...

Additional arguments. Currently unused.

Value

A numeric vector of longitude values expressed in the requested convention.

Details

Longitude values are modified only when needed. For `primeMeridian = "center"`, values greater than `180` are shifted by subtracting `360`. For `primeMeridian = "left"`, negative values are shifted by adding `360`.

See also

[findPrimeMeridian()]

Examples

if (FALSE) { # \dontrun{
lon <- c(170, 180, 190, 350)

checkLongitude(lon, primeMeridian = "center")
checkLongitude(lon, primeMeridian = "left")
} # }