s10fig10.m

Industrial Mathematics

% figure 10.10 Bode Plots
%
Q=4;
wmin = 0;           % min rad freq to view
wmax = 3;           % max rad freq to view
dw=0.01;             % step size
w=wmin:dw:wmax;     % radian frequency vector        
s = w*i;            %  
N= s/Q;           
D = s.*s  + s/Q + 1;
H = N./D ;           % transfer
r = abs(H);         % gain at freq w
phi = angle(H);     % phase lead
 plot(w,r,'k-')    % gain vs freq in Hz
%plot(w,phi*180/pi,'k-')    %for phase plot in degrees
%plot(w,20*log10(r),'k-')     %  for decibels