Scilab Function
Last update : April 1993

zgrid - zgrid plot

### Calling Sequence

  `zgrid()`

### Description

plots z-plane grid lines: lines of constant damping factor (zeta) and natural frequency (Wn) are drawn in within the unit Z-plane circle.

Iso-frequency curves are shown in frequency*step on the interval [0,0.5]. Upper limit corresponds to Shannon frequency `( 1/dt > 2*f )`.

### See Also

`frep2tf`, `freson`,