f
ymin = -40; ymax = 0;
plot([1:360], 20*log10(abs(y)), <span class="keyword">...</span>
     [theta_tar theta_tar],[ymin ymax],<span class="string">'g--'</span>,<span class="keyword">...</span>
     [theta_tar+halfbeam theta_tar+halfbeam],[ymin ymax],<span class="string">'r--'</span>,<span class="keyword">...</span>
     [theta_tar-halfbeam theta_tar-halfbeam],[ymin ymax],<span class="string">'r--'</span>);
xlabel(<span class="string">'look angle'</span>), ylabel(<span class="string">'mag y(theta) in dB'</