Global Index (short | long) | Local contents | Local Index (short | long)
bodeplot(G,sd,C,mode)
BODEPLOT Plots the Bode diagram of a transfer function or spectrum. BODEPLOT(G) or BODEPLOT(G,SD) G is entered as the transfer function(s) or spectrum (spectra) of the standard frequency function format, produced by TH2FF, SPA or ETFE. See also FREQFUNC. Several plots in the same diagram are obtained by BODEPLOT([G1 G2 .. Gn]) The transfer functions Gk need not be given at the same frequencies. If SD is specified to a number larger than zero, also confidence intervals for the functions (corresponding to SD standard deviations) are shown as dash-dotted curves. The default mode is that amplitude and phase plots are shown simul- taneously, for each input (noise spectrum) present in G. For spectra the phase plots are omitted. ENTER will advance the plot from one input to the next (if any). To show amplitude or phase plots only use BODEPLOT(G,SD,'A') and BODEPLOT(G,SD,'P'), respectively. To ob- tain all plots in the same diagrams use BODEPLOT(G,SD,C,'same'). C is here 'A', 'P' or 'B' for amplitude, phase or both plots. (In these cases SD can be omitted for default) See also FFPLOT, NYQPLOT.
| This function calls | This function is called by |
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function bodeplot(G,sd,C,mode)
% L. Ljung 10-1-86, revised 7-7-87,10-2-92
% Copyright (c) 1986-98 by The MathWorks, Inc.
% $Revision: 2.5 $ $Date: 1997/12/03 23:16:16 $
if nargin<1
disp('Usage: BODEPLOT(G)')
disp(' BODEPLOT(G,SD,C,MODE)')
return
end
if nargin<4 , mode=[];end
if nargin<3, C=[];end
if nargin<2, sd=[];end
if isempty(mode),mode='sep';end
if isempty(C),C='B';end
if isempty(sd),sd=0;end
abp=['a';'A';'b';'B';'p';'P'];
if sum(sd(1)==abp)>0, if length(C)>1,mode=C;end,C=sd;sd=0;end
if length(sd)>1,mode=sd;sd=0;end
mode=mode(1:3);
if mode=='SEP', mode='sep';end
if mode=='SAM', mode='sam';end
if mode~='sam', mode='sep';end
if C == 'a', C='A'; end
if C == 'p', C='P'; end
if C == 'b', C='B'; end
cols=get(gca,'colororder');
if sum(cols(1,:))>1.5 % Note colors start with the second color
colord=['b','y','m','c','r','g']; % Dark background
else
colord=['k','b','g','r','c','m']; % Light background
end
[m,n]=size(G);
inputs1=G(1,:);mo=fix(inputs1/1000);mmo=max(mo);
kko=[]; % The output indices
for k=[0:mmo],if length(find(mo==k))>0,kko=[kko k];end,end
G=G(2:m,:);
for ko=kko+1
inputs=inputs1-(ko-1)*1000;
mi=max(inputs(find(inputs<19)));
kki=[]; % The input indices
for k=[1:mi 0], if length(find(inputs==k))>0,kki=[kki k];end,end
if sum(kki)==0 & C=='B', C='A';end
if mode=='sep'
for k=kki
if k==0 & C=='B',C='A';end
newplot;
if C=='B',subplot(211),else subplot(111),end
if C=='A'| C=='B'
indmod=find(inputs==100+k);ind2=find(inputs==k);
for kk=1:length(indmod)
col=colord(mod(kk,6)+1);
semilogy(G(:,indmod(kk))/2/pi,G(:,ind2(kk)),col),hold on
if sd>0
if length(inputs)>=indmod(kk)+2
if inputs(indmod(kk)+2)==k+50
semilogy(G(:,indmod(kk))/2/pi,G(:,indmod(kk)+1)+...
sd*G(:,indmod(kk)+2),[col,'-.'])
semilogy(G(:,indmod(kk))/2/pi,max(G(:,indmod(kk)+1)-...
sd*G(:,indmod(kk)+2),0),[col,'-.'])
else
disp('No confidence info for this model.')
end
else
disp('No confidence info for this model.')
end
end
end
hold off
xlabel('frequency (Hz)')
if k~=0,title(['AMPLITUDE PLOT, input # ',int2str(k),' output # ',int2str(ko)])
else title(['SPECTRUM output # ',int2str(ko)]),end
end
if ((C=='B')|(C=='P'))&k~=0
if (C=='B'), subplot(212), end
if (C=='P'),newplot;subplot(111),end
indmod=find(inputs==100+k);ind2=find(inputs==20+k);
for kk=1:length(indmod)
col=colord(mod(kk,6)+1);
plot(G(:,indmod(kk))/2/pi,G(:,ind2(kk)),col),hold on
if sd>0
if length(inputs)>=indmod(kk)+4
if inputs(indmod(kk)+4)==k+70
plot(G(:,indmod(kk))/2/pi,G(:,indmod(kk)+3)+...
sd*G(:,indmod(kk)+4),[col,'-.'])
plot(G(:,indmod(kk))/2/pi,G(:,indmod(kk)+3)-...
sd*G(:,indmod(kk)+4),[col,'-.'])
end
end
end
end
hold off
title(['PHASE PLOT, input # ',int2str(k),' output # ',int2str(ko)])
xlabel('frequency (Hz)')
ylabel('phase')
end
if k~=kki(length(kki)),pause,end
end
end
if mode=='sam'
if C=='B',subplot(211),else subplot(111),end
if C=='B' | C=='A'
semilogy(G(:,find(inputs>99&inputs<120))/2/pi,G(:,find(inputs<20&inputs>-1)))
if sd>0,hold on,
ind=find(inputs<69 & inputs>49);
semilogy(G(:,ind-2)/2/pi,G(:,ind-1)+G(:,ind)*sd,'-.')
semilogy(G(:,ind-2)/2/pi,max(G(:,ind-1)-sd*G(:,ind),0),'-.'),hold off,end
xlabel('frequency (Hz)')
title(['AMPLITUDE PLOT output #',int2str(ko)])
end
if C=='B'| C=='P'
if C=='B',subplot(212),else subplot(111),end
plot(G(:,find(inputs>100&inputs<120))/2/pi,G(:,find(inputs<39 & inputs>19)))
if sd>0,hold on
ind=find(inputs<89 & inputs>69);
plot(G(:,ind-4)/2/pi,G(:,ind-1)+G(:,ind)*sd,'-.')
plot(G(:,ind-4)/2/pi,G(:,ind-1)-sd*G(:,ind),'-.'),hold off,end
xlabel('frequency (Hz)')
ylabel('phase')
title(['PHASE PLOT output #',int2str(ko)])
end
end,if ko~=kko(length(kko))+1,pause,end
end
hold off
set(gca,'NextPlot','replace');
set(gcf,'NextPlot','replace');