
plmap: Plot continental outline in world coordinates 

DESCRIPTION:

    This function is used in example 19. 

SYNOPSIS:

plmap(mapform, type, minlong, maxlong, minlat, maxlat)

ARGUMENTS:

    mapform (void (*) (PLINT, PLFLT *, PLFLT *), input) :    A user
    supplied function to transform the coordinate  longitudes and
    latitudes to a plot coordinate system.     By using this transform,
    we can change from a longitude,  latitude coordinate to a polar
    stereographic project, for  example.  Initially, x[0]..[n-1] are
    the longitudes and y[0]..y[n-1]  are the corresponding latitudes. 
    After the call to mapform(), x[]  and y[] should be replaced by
    the corresponding plot coordinates.   If no transform is desired,
    mapform can be replaced by NULL. 

    type (const char *, input) :    type is a character string. The value
    of this parameter determines the type of background. The possible
    values are: "globe" -- continental outlines 
        "usa" -- USA and state boundaries 
        "cglobe" -- continental outlines and countries 
        "usaglobe" -- USA, state boundaries and continental outlines 


    minlong (PLFLT, input) :    The value of the longitude on the left
    side of the plot.  The value of minlong must be less than the
    value of maxlong, and the  quantity maxlong-minlong must be less
    than or equal to 360. 

    maxlong (PLFLT, input) :    The value of the longitude on the right
    side of the plot. 

    minlat (PLFLT, input) :    The minimum latitude to be plotted on the
    background.   One can always use -90.0 as the boundary outside the
    plot window  will be automatically eliminated.    However, the
    program will be  faster if one can reduce the size of the
    background plotted. 

    maxlat (PLFLT, input) :    The maximum latitudes to be plotted on the
    background.   One can always use 90.0 as the boundary outside the
    plot window  will be automatically eliminated. 
