function [x_ds3,y_ds3]=northarrow(h,w,x0,y0,theta0)
    
%example
% x0=600;      
%     y0=400;
%     theta0 =-131.65534968173412+90;
%h=100
%w=100    


x_ds=[0 0 -.20 0 .20 0]*h;
y_ds=[0 1 .60 .60 .60 1]*w;

  
    
 x_ds2 = -(x_ds).*sind(theta0) + (y_ds)*cosd(theta0); 
 y_ds2 =  -(x_ds)*cosd(theta0) - (y_ds)*sind(theta0);   
 
 x_ds3=x_ds2+x0;
 y_ds3=y_ds2+y0;
 

%  xdata = [x_ds3(2) x_ds3(3) x_ds3(4)];
%  ydata =  [y_ds3(2) y_ds3(3) y_ds3(4)];
%  zdata = [1 1 1]; 
% hold on
% p = patch(xdata,ydata,zdata,'k') 
% set(p,'FaceColor','interp')

 plot(x_ds3,y_ds3,'w','linewidth',2)
 t1=text(min(x_ds3)+0.2*w,min(y_ds3),'N') 
set (t1,'Fontsize',16,'color','w')
 
