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rootlocusplotter

Rootlocusplotter is a software tool used in control theory and engineering to generate root locus plots for linear time-invariant (LTI) systems. It provides a visualization of how the closed-loop pole locations in the complex plane move as a system gain K varies, typically under negative feedback.

The tool accepts standard representations of plant and controller, such as a transfer function G(s) or a

Output includes the root locus plot with poles and zeros marked, asymptotes indicated, and optionally breakaway

Rootlocusplotter is used to assess stability margins and guide controller design, providing intuition for how choices

The concept of root locus originates in classical control theory and remains a staple method for preliminary

state-space
model,
and
computes
the
locus
of
closed-loop
poles
as
K
ranges
over
a
specified
interval.
For
single-input
single-output
systems
the
construction
is
based
on
the
characteristic
equation
1+K
G(s)H(s)=0,
tracing
the
trajectory
of
poles
as
K
increases
from
0
to
infinity.
Zeros
of
the
open-loop
transfer
function
are
plotted
as
zeros
and
open-loop
poles
as
poles.
and
break-in
points,
intercepts
on
the
real
axis,
and
gain
values
at
key
points.
Some
implementations
offer
damping
ratio
and
natural
frequency
lines
to
aid
interpretation,
as
well
as
options
for
interactive
zooming,
labeling,
and
annotation.
of
K
affect
stability
and
performance.
It
is
commonly
integrated
into
control
system
toolchains
in
environments
such
as
MATLAB,
Python,
or
Octave,
either
as
part
of
a
dedicated
toolbox
or
as
a
scripting
library
around
standard
G(s)
and
H(s)
representations.
stability
analysis
and
gain
tuning.
Related
visualization
tools
include
Nyquist
and
Bode
plots,
which
together
offer
complementary
perspectives
on
system
behavior.