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## Re: Polynomial Toolbox

 From: Riccardo Corradini Subject: Re: Polynomial Toolbox Date: Fri, 6 Apr 2007 08:49:05 +0200 (CEST)

> Hi all,
> I searched something similar for octave2.9.10 of
> Polynomial Toolbox http://polyx.com, but unfortunately
> I didn't find anything.
> In particular I would like to use rmf2lmf routine.
> Is there something similar in gnu octave?
> Thanks a lot to all of you.
> Cheers
> Riccardo

Can you describe what your function does?
Maybe it exists in another form.

-Muthu
Sure

This is taken from OnLineManual.pdf at page 107

Left and right polynomial matrix fractions
Given a left polynomial fraction Ql−1Pl there always exists a right fraction Pr Qr−1 so
that
Ql−1Pl = Pr Q r−1
The polynomial matrices Pr and Qr are highly nonunique because if T is any
square nonsingular polynomial matrix of the same size as Qr then
(Pr T )(Qr T )−1 = Pr Q r−1
Left and right polynomial matrix fractions
Polynomial matrix fractions and LTI systems
The Polynomial Toolbox routine
lmf2rmf,
rmf2lmf
[Pr,Qr] = lmf2rmf(Pl,Ql)
converts the left fraction Ql−1Pl to the right fraction Pr Qr−1 such that Pr and Qr are
coprime. Similarly, the routine
[Pl,Ql] = rmf2lmf(Pr,Qr)
converts a (not necessarily coprime) right fraction to a coprime left fraction.
Conversion of the left fraction Ql−1Pl of the previous example to the right fraction
Example
Pr Qr−1 results in
[Rr,Qr] = lmf2rmf(Pl,Ql)
Constant polynomial matrix: 1-by-1
Rr =
1
Constant polynomial matrix: 1-by-1
Qr =
1