dhnorm discrete H-infinity norm

## Syntax

                hinfnorm = dhnorm(sl)
                hinfnorm = dhnorm(sl, tol)
                hinfnorm = dhnorm(sl, normax)
                hinfnorm = dhnorm(sl, tol, normax)

## Arguments

sl

  the state space system (`syslin` list) (discrete-time)

tol

  tolerance in bisection step, default value `0.01`

normax

  upper bound for the norm , default value is `1000`

hinfnorm

  the discrete infinity norm of `Sl`

## Description

produces the discrete-time infinity norm of a state-space system (the maximum over all frequencies on the unit circle of the maximum singular value).

## See also

- h_norm
- linfn