az = 30;
sp = .1;
mpr = [-6:.1:6]';
mpa = az*ones(size(mpr));
[mpx,mpy]=xycoord(mpr,mpa);
[shiftx,shifty]=xycoord(6,az+90);
X = [mpx'+shiftx; mpx'-shiftx];
Y = [mpy'+shifty; mpy'-shifty];

h=line(X,Y); set(h,'color',[0 0 0]);
axis([-4 4 -4 4])
axis('square')