function cmap(map)
if (nargin>0) 
   if (length(map)==2 & (((map(1)=='r' & map(2) =='g') |(map(1)=='g' & map(2) =='r'))|...
			 ((map(1)=='R' & map(2) =='G') |(map(1)=='G' & map(2) =='R'))))
	map=zeros(64,3); map(:,2)=flipud(((0:1:63)/63)'); map(:,1)=((0:1:63)/63)'; 
   end;
else
	map='jet'; 
end
colormap(map)