Scilab Function

g_margin - gain margin

### Sequence d'appel

  `[gm [,fr]]=g_margin(h)`

### Parametres

- `h` : `syslin` list representing a linear system in state-space or transfer form

### Description

returns `gm`, the gain margin in dB of `h` (SISO plant) and `fr`, the achieved corresponding frequency in hz. The gain margin is values of the system gain at points where the nyquist plot crosses the negative real axis.

### Exemples

    h=syslin('c',-1+%s,3+2*%s+%s^2)
    [g,fr]=g_margin(h)
    [g,fr]=g_margin(h-10)
    nyquist(h-10)

### Voir aussi

`p_margin` `black` `chart` `nyquist`