lonlat2utm does the inverse operation. For general
projections and their inverses, use lonlat2map and
map2lonlat.
Other functions related to maps: lonlat2map,
lonlat2utm, map2lonlat,
mapArrows, mapAxis,
mapContour,
mapDirectionField, mapGrid,
mapImage, mapLines,
mapLocator,
mapLongitudeLatitudeXY,
mapPlot, mapPoints,
mapPolygon, mapScalebar,
mapText, mapTissot,
oceCRS, shiftLongitude,
usrLonLat