pplane.m

该程序是二阶琐相环的防震实例 仿真结果给出了二阶琐相环的相平面

function[] =pplane(x,y,nsettle)
ln =length(x);
maxfreq=max(y);
minfreq=min(y);
close
axis([-1 1 1.1*minfreq 1.1*maxfreq]);
hold on
j=nsettle;
while j<ln
     i=1;
     while x(j)<pi& j<ln
         a(i)=x(j)/pi;
         b(i)=y(j);
         j=j+1;
         i=i+1;
     end
     plot(a,b,'k')
     a=[];
     b=[];
     x=x-2*pi;
end
hold off
title('Phase-Plane Plot')
xlabel('Phase Error/Pi'); ylabel('Frequency Error in Hertz')
grid