7 Example 8-24 OGATA 4ed(Bode plot, resonant peak magnitude, resonant peak frequency, bandwidth)

Laplace.T	Root-locus	Transient response	Frecuency response

7 Example 8-24 OGATA 4ed(Bode plot, resonant peak magnitude, resonant peak frequency, bandwidth)
Let's calculate Bode plot, resonant peak magnitude, resonant peak frequency, bandwidth by Scilab

$\begin{displaymath}G(s)=\frac{1}{s\cdot (5\cdot s+1)\cdot (s+1)}\end{displaymath}$
Scilab program
s=%s/(%pi*2);
g=1/(s*(0.5*s+1)*(s+1));
gc=g/. 1;
gcs=syslin('c',gc);
clf;
bode(gcs);
w=logspace(-2,3,100);
gsf=tf2ss(gcs);
[frq1,rep] =repfreq(gsf,w);
[db,phi]=dbphi(rep);
[mdb,k]=max(db);
resonantf=w(k)
resonantpeak=mdb
n=1;
while db(n)>-3,
n=n+1;
end;
bandwidth=w(n)
Solutions:
 -->resonantf=w(k)
 resonantf  =
 
    0.8302176  
-->resonantpeak=mdb
 resonantpeak  =
 
    5.2696204  

    
-->bandwidth=w(n)
 bandwidth  =
 
    1.3219411