ZOH:

-------------------------------------------------------------------------------
   Create a model of a zero-order-hold using Pad� approximants.
   The ZOH will be scaled by 1/T (as if it had a sampler in the
   loop.)
-------------------------------------------------------------------------------
   Form:
   [a, b, c, d] = ZOH( T, n )
   [num, den]   = ZOH( T, n )
-------------------------------------------------------------------------------

   ------
   Inputs
   ------
   T                   Hold period
   n                   Number of terms (optional)

   -------
   Outputs
   -------
   a or num            Numerator polynomial or plant matrix
   b or den            Denominator polynomial or input matrix
   c                   Measurement matrix
   d                   Feedthrough matrix

-------------------------------------------------------------------------------

Children:

Common: Control/FResp
Common: Control/ND2SS
Common: Math/Pade
Common: Math/SubPoly