colregul removing poles and zeros at infinity

## Syntax

    [Stmp, Ws] = colregul(Sl, alfa, beta)

## Arguments

Sl,Stmp

  `syslin` lists

alfa,beta

  reals (new pole and zero positions)

## Description

computes a prefilter `Ws` such that `Stmp=Sl*Ws` is proper and with full rank `D` matrix.

Poles at infinity of `Sl` are moved to `alfa`;

Zeros at infinity of `Sl` are moved to `beta`;

`Sl` is assumed to be a left invertible linear system (`syslin` list) in state-space representation with possibly a polynomial `D` matrix.

## See also

- invsyslin
- inv
- rowregul
- rowshuff