PLOTM  Project 2D line objects onto the current map axes
 
   PLOTM(lat,lon) projects line objects onto the current
   map axes.  The input latitude and longitude data must be in
   the same units as specified in the current map axes.
   PLOTM will clear the current map if the hold state is off.
 
   PLOTM(lat,lon,'LineSpec') uses any valid LineSpec string to
   display the line object.
 
   PLOTM(lat,lon,'PropertyName',PropertyValue,...) uses
   the line object properties specified to display the line
   objects.  Except for xdata, ydata and zdata, all line properties,
   and styles available through PLOT are supported by PLOTM.
 
   PLOTM(mat,...) uses a single input matrix, mat = [lat lon],
   where the first half of the matrix columns represents the
   latitude data and the second half of the columns represent
   longitude data.
 
   h = PLOTM(...) returns the handles to the line objects displayed.
 
   PLOTM, without any inputs, will activate a GUI to project line
   objects onto the current map axes.
 
   See also PLOT3M, PLOT, LINEM, LINE