chart - Nichols chart
plot the Nichols'chart.
The default values for gain and phase are respectively :
[-12 -8 -6 -5 -4 -3 -2 -1.4 -1 -.5 0.25 0.5 0.7 1 1.4 2 2.3 3 4 5 6 8 12]
[-(1:10) , -(20:10:160)]
s=poly(0,'s') h=syslin('c',(s^2+2*0.9*10*s+100)/(s^2+2*0.3*10.1*s+102.01)) black(h,0.01,100,'(s^2+2*0.9*10*s+100)/(s^2+2*0.3*10.1*s+102.01)') chart(list(1,0,2,3)); xbasc() h1=h*syslin('c',(s^2+2*0.1*15.1*s+228.01)/(s^2+2*0.9*15*s+225)) black([h1;h],0.01,100,['h1';'h']) chart([-8 -6 -4],[80 120],list(1,0));