# nyquist

Nyquist diagram.

## Syntax

nyquist(sys)

nyquist(sys, w)

nyquist(..., fmt, ...)

nyquist(..., property, value, ...)

[re, im, w] = nyquist(...)

## Inputs

sys
A linear time-invariant transfer function or state space system.
Type: class
w
The vector of frequencies at which to compute the response. The units are radians/sec for continuous time, and Hz for discrete time. If w is a two-element vector, it contains the range of frequencies over which to compute the response. The units are radians/sec for continuous time, and Hz for discrete time.
Type: double
Dimension: vector
fmt
Plot format arguments. See the plot function help.
Type: string
Dimension: vector
property
Plot property arguments that are paired with a following value. See the plot function help.
Type: string
Dimension: vector
value
Plot property value arguments. See the plot function help.
Type: integer
Dimension: scalar

## Outputs

re
The real component of the response.
Type: double
Dimension: vector
im
The imaginary component of the response.
Type: double
Dimension: vector
w
The vector of frequencies at which to compute the response. The units are radians/sec for continuous time, and Hz for discrete time.
Type: double
Dimension: vector

## Example

Create the Nyquist diagram of the given 3rd order analog transfer function, with the plot in red.

tfo = tf([1,1,3,3],[1,-3,3,-1]);
nyquist(tfo,'r');