procfilt.m

realize analysis and design for computer-controlled system

% Generates Fig 5.XX
% Computer Controlled Systems (3rd ed)
% Author: B. Wittenmark
% Last edit: 1997-07-04
% Copyright (c) 1996 by K. J. 舠tr鰉, B. Wittenmark and
% Department of Automatic Control, Lund Institute of
% Technology, Lund, Sweden

newplot;clf;
set(gcf,'PaperUnits','centimeters','PaperPosition',[2 2 15.5 11])
set(gcf,'Units','centimeters','position',get(gcf,'PaperPosition'))

aproc=conv([1 -1],[1 -1.7124 0.9512]);
afilt=[1 -0.7505 0.2466];
a=conv(aproc,afilt);
b=0.0001420*conv(conv([1 12.1314],[1 1.3422]),conv([1 0.2234],[1 -0.0023]));

% Plot Unit circle
t=0:.1:6.3;
plot(sin(t),cos(t),'k--')
axis([-2.5 1.5 -1 1]);
axis('equal')
hold on
hpl=plot(real(roots(b)),imag(roots(b)),'mo',real(roots(a)),...
imag(roots(a)),'kx','markersize',8,'linewidth',2);
%plot(real(roots(b)),imag(roots(b)),'mo','markersize',8,'linewidth',2);
plot(-2.5,0,'mo','markersize',8,'linewidth',2)
zgrid
%title('Fig 5.23');
set(gca,'Fontsize',12,'Fontname','NewCenturySchlbk');
set(gca,'xtick',[-2 -1 0 1],'ytick',[-1 0 1]);
set(hpl,'MarkerSize',8)
ylabel('Imaginary axis','Fontname','NewCenturySchlbk','Fontsize',12)
xlabel('Real axis','Fontname','NewCenturySchlbk','Fontsize',12)
%Draw axis
plot([-6 2],[0 0],'k:',[0 0],[-3 3],'k:')
hold off