Documentation

# zgrid

Generate z-plane grid of constant damping factors and natural frequencies

## Syntax

``zgrid``
``zgrid(zeta,wn)``
``zgrid(___,'new')``
``zgrid(AX,___)``

## Description

example

````zgrid` generates a grid of constant damping factors from 0 to 1 in steps of 0.1 and natural frequencies from 0 to π in steps of π/10 for root locus and pole-zero maps. `zgrid` then plots the grid over the current axis. `zgrid` creates the grid over the plot without altering the current axis limits if the current axis contains a discrete z-plane root locus diagram or pole-zero map.```
````zgrid(zeta,wn)` plots a grid of constant damping factor and natural frequency lines for the damping factors and normalized natural frequencies in the vectors `zeta` and `wn`, respectively. `zgrid(zeta,wn)` creates the grid over the plot if the current axis contains a discrete z-plane root locus diagram or pole-zero map. You can also plot frequency lines for non-normalized (true) frequencies using `zgrid(zeta,wn/Ts)`, where `Ts` is the sample time.Alternatively, you can select Grid from the context menu to generate the same z-plane grid.```
````zgrid(___,'new')` clears the current axes first and sets `hold on`.```
````zgrid(AX,___)` plots the z-plane grid on the `Axes` or `UIAxes` object in the current figure with the handle `AX`. Use this syntax when creating apps with `zgrid` in the App Designer.```

## Examples

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To see the z-plane grid on the root locus plot, type

`H = tf([2 -3.4 1.5],[1 -1.6 0.8],-1)`
```H = 2 z^2 - 3.4 z + 1.5 ------------------- z^2 - 1.6 z + 0.8 Sample time: unspecified Discrete-time transfer function. ```
```rlocus(H) zgrid axis equal``` ## Input Arguments

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Damping ratio, specified as a vector in the same order as `wn`.

Normalized natural frequency, specified as a vector. You can also plot frequency lines for non-normalized (true) frequencies using `zgrid(zeta,wn/Ts)`, where `Ts` is the sample time.

Object handle, specified as an `Axes` or `UIAxes` object. Use `AX` to create apps with `zgrid` in the App Designer.