12.6. Finding Gain K at a Given Point on the Root Locus
The value of gain K at any point on the root locus can be obtained by using the interactive command:
[K, r] = rlocfind(n, d)
where r is a column vector giving the location of roots corresponding to the gain K.
This command will shift the control to the root locus figure window and a message 'select a point in the figure window' will appear in the command window. A crosshair cursor will also appear in the figure window, and this cursor can be moved to select the exact point on the root locus using the mouse. At the desired point on the root locus, left button of the mouse is clicked. The values of the selected point, corresponding gain and roots are displayed in the command window.