rlocus
                Display root locus plot of the specified SISO system.
Inputs
LTI model. Must be a single-input and single-output (SISO) system.
The increment used in computing gain values.
Minimum value of k.
Maximum value of k.
Outputs
Data points plotted: in column 1 real values, in column 2 the imaginary values.
Gains for real axis break points.
Block Diagram
  u    +         +---+      +------+             y
 ------>(+)----->| k |----->| SISO |-------+------->
         ^ -     +---+      +------+       |
         |                                 |
         +---------------------------------+
  | 
See also: rlocusx
Source Code: rlocus
 s = tf('s');
 g = (s^2+2*s+2)/(s*(s^4+9*s^3+33*s^2+51*s+26));
 rlocus(g);
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