/*
 Example 6.8 Nyquist Plot for a Second-order System
*/
 
del *;
"************************************************"
"**                                            **"
"**                 example 6.8                **"
"**   Nyquist Plot for a Second-order System   **"
"**                                            **"
"************************************************"
" "
sleep(2);
" "
" r--O--->[K]--->[1/(s+1)^2]--->"
"   -|                       |  "
"    |                       |  "
"    -------------------------   "
" "
sleep(2);
 
num = 1;
den = [1 2 1];
 
"Root locus"
" "
// Figure 6.20 - Root locus
figure(1);
rlocus(num,den);
 
"Bode plot"
" "
// Figure 6.21 - Open loop Bode plotfigure(2);
w = logspace(-2, 2, 1000);
bode(num,den,w);
 
"Nyquist plot"
" "
// Figure 6.22 - Nyquist plotfigure(3);
nyquist(num,den);