Convert zero-pole-gain filter parameters to state-space form
zp2ss converts a zero-pole-gain representation
of a given system to an equivalent state-space representation.
[A,B,C,D] finds a single input,
multiple output, state-space representation
given a system in factored transfer function form.
p specifies the pole locations,
z the zero locations with as many columns
as there are outputs. The gains for each numerator transfer function
are in vector
D matrices are returned in controller canonical
Inf values may be used as place holders in
some columns have fewer zeros than others.