h_norm H-infinity norm

## Syntax

                [hinfnorm, frequency] = h_norm(sl)
                [hinfnorm, frequency] = h_norm(sl, rerr)

## Arguments

sl

  the state space system (`syslin` list)

rerr

  max. relative error, default value `1e-8`

hinfnorm

  the infinity norm of `Sl`

frequency

  frequency at which maximum is achieved

## Description

produces the infinity norm of a state-space system (the maximum over all frequencies of the maximum singular value).

## See also

- linfn
- linf
- svplot