function rplot(R, theta)
%
%  the function rplot(R, theta) makes a radial plot 
%  where the vector R is the radius (distance from the 
%  center), and the vector theta the counterclockwise angle 
%  (in degrees) from the horizontal axis x
%
%---------------------------------------------------------------
%  Written by Vassilis Zervakis, while at 
%             AINCO-Interocean, Madrid, Spain, in December 1995
%---------------------------------------------------------------
%
   X = R .* cos( theta * pi / 180. );
   Y = R .* sin( theta * pi / 180. ); 
   axis('equal');
   plot(X, Y, '+');
