chart - Nichols chart

Calling Sequence

chart([flags])

chart(gain [,flags])

chart(gain,phase [,flags])

Parameters

• gain : real vector ( gains (in DB))
• phase : real vector (phases (in degree))
• flags : a list of at most 4 flags list(sup [,leg [,cm [,cphi]]])
  • sup : 1 indicates superposition on the previous plot 0 no superposition is done
  • leg : 1 indicates that legends are drawn, o: no legends
  • cm : color number (see plot2d) for gain curves
  • cphi : color number (see plot2d) for phase curves

Description

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)]

Examples

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));