span>);
axis([0 360 ymin ymax]);

<span class="comment">% polar plot</span>
figure(3), clf
zerodB = 50;
dBY = 20*log10(abs(y)) + zerodB;
plot(dBY.*cos(pi*theta/180), dBY.*sin(pi*theta/180), <span class="string">'-'</span>);
axis([-zerodB zerodB -zerodB zerodB]), axis(<span class="string">'off'</span>), axis(<span class="string">'square'</span>)
hold <span class="string">on</span>
plot(zerodB*cos(pi*theta/180),zerodB*sin(pi*theta/180),<span class="string">'k:'</span>) <span class="comment">% 0 dB</span>
plot