This is a utility function used by mapGrid(). It works
simply by subtracting 180 from each longitude, if any longitude
in the vector exceeds 180.
shiftLongitude(longitudes)numerical vector of longitudes.
vector of longitudes, shifted to the desired range.
matrixShiftLongitude() and standardizeLongitude().
Other functions related to maps:
formatPosition(),
lonlat2map(),
lonlat2utm(),
map2lonlat(),
mapArrows(),
mapAxis(),
mapContour(),
mapCoordinateSystem(),
mapDirectionField(),
mapGrid(),
mapImage(),
mapLines(),
mapLocator(),
mapLongitudeLatitudeXY(),
mapPlot(),
mapPoints(),
mapPolygon(),
mapScalebar(),
mapText(),
mapTissot(),
oceCRS(),
oceProject(),
usrLonLat(),
utm2lonlat()