Compute or plot passivity index as function of frequency

`passiveplot(`

plots
the relative passivity indices of the dynamic system `G`

)`G`

as
a function of frequency. When `I + G`

is minimum
phase, the relative passivity indices are the singular values of ```
(I
- G)(I + G)^-1
```

. The largest singular value measures the
relative excess `(R < 1)`

or shortage ```
(R
> 1)
```

at each frequency. See `getPassiveIndex`

for
more information about the meaning of the passivity index.

`passiveplot`

automatically chooses the frequency
range and number of points for the plot based on the dynamics of `G`

.

`passiveplot(___,`

plots
the passivity index for frequencies specified by `w`

)`w`

.

If

`w`

is a cell array of the form`{wmin,wmax}`

, then`passiveplot`

plots the passivity index at frequencies ranging between`wmin`

and`wmax`

.If

`w`

is a vector of frequencies, then`passiveplot`

plots the passivity index at each specified frequency.

You can use this syntax with any of the previous input-argument combinations.