LONGLIB also supports the plotting of maps of the physical earth's surface by providing mapping routines. Two data files (EARTH.DAT and LNDSEA1.DAT) are included in the LONGLIB graphics library package. EARTH.DAT contains the digitized locations of the edges of the earth's landmasses. It forms the basis of a set of EARTH OUTLINE mapping routines discussed below. LNDSEA1.DAT contains a bit map of land/sea areas. It forms the basis of the LAND AREA mapping routines discusses in the second section.
Note: these routines assume that the plot package has already been opened.