fs = 100e3;
f0 = 100;
w0 = 2*pi*f0;
Q  = 10;
z = tf('z', 1/fs);

for f0 = [ 100 1e3 10e3 ]
    w0 = 2*pi*f0;
    Hz = z*(1-z) / (z^2*(fs/w0 + w0/fs + 1/Q) - z*(2*fs/w0 + 1/Q) + fs/w0);
    bode(Hz);
    hold on;
end

legend('fs/f0 = 1000', '100', '10', 3);
fixfig;
hold off;

close all;

for f0 = [ 10e3 ]
    w0 = 2*pi*f0;
    Hz = z*(1-z) / (z^2*(fs/w0 + w0/fs + 1/Q) - z*(2*fs/w0 + 1/Q) + fs/w0);
    pzmap(Hz);
    hold on;
end

fixfig;
hold off;