Draws the Hall chart
hallchart([ modules [,args [,colors]]])
:modules real vector ( modules (in dB)) : :args real vector (phases (in degree)) : :colors a scalar or a vector, the color indices for isogain and iso
phase curves
:
plot the Hall’chart: iso-module and iso-argument contours of y/(1+y) in the real(y), imag(y) plane
hallchart may be used in cunjunction with nyquist.
The default values for modules and args are respectively :
[-20 -10 -6 -4 -2 2 4 6 10 20]
[-90 -60 -45 -30 -15 15 30 45 60 90]
This function superseeds the m_circle function
The hallchart function create a single compound object which is generaly the last child of the current axes. This compound object contains a set of compound objects, one for each grid curve. The first ones are the iso module curves and the last one the iso-argument contours. Each of these compound objects contains a Polyline object (the curve) and a Text object (the label). The following piece of code can be used to change the color of the ith iso module curve:
`clf`_();hallchart()
ax=`gca`_();//handle on current axes
c=ax.children($).children;// the handles on the chart grid curves
i=4; //the index of the -4dB curve
ci=c(i); //the handle on the -4dB curve
ci.children(1).foreground=`color`_('red'); //draw it in red
j=3; // the index of the -45° curve
cj=c(10+j); //the handle on the -45° curve
cj.children(1).thickness=3;//draw it thicker
//Hall chart
`clf`_();hallchart()
//Hall chart as a grid for nyquist
s=`poly`_(0,'s');
Plant=`syslin`_('c',16000/((s+1)*(s+10)*(s+100)));
//two degree of freedom PID
tau=0.2;xsi=1.2;
PID=`syslin`_('c',(1/(2*xsi*tau*s))*(1+2*xsi*tau*s+tau^2*s^2));
`clf`_();
`nyquist`_([Plant;Plant*PID],0.5,100,["Plant";"Plant and PID corrector"]);
hallchart(colors=`color`_('light gray')*[1 1])
//move the caption in the lower rigth corner
ax=`gca`_();Leg=ax.children(1);
Leg.legend_location="in_lower_right";