copfac right coprime factorization of continuous time dynamical systems

## Syntax

                [N, M, XT, YT] = copfac(G)
                [N, M, XT, YT] = copfac(G, polf, polc, tol)

## Arguments

G

  a continuous-time linear dynamical system.

polf, polc

  respectively the poles of `XT` and `YT` and the poles of `n` and `M` (default values =-1).

tol

  real threshold for detecting stable poles (default value `100*%eps`)

N,M,XT,YT

  continuous-time linear dynamical systems.

## Description

`[N,M,XT,YT]=copfac(G,[polf,polc,[tol]])` returns a right coprime factorization of `G`.

`G= N*M^-1` where `N` and `M` are stable, proper and right coprime. (i.e. `[N M]` left-invertible with stability)

`XT` and `YT` satisfy:

`[XT -YT].[M N]' = eye` (Bezout identity)

`G` is assumed stabilizable and detectable.

## See also

- syslin
- lcf

## History

5.4.0 `Sl` is now checked for continuous time linear dynamical system. This modification has been introduced by this commit