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From: Arthur G <gorramfreak+news@gmail.com>
Newsgroups: comp.soft-sys.matlab
Date: Sat, 23 Feb 2008 07:55:43 -0500
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Subject: Re: polynomial factorization
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On 2008-02-22 20:10:20 -0500, "John D'Errico" 
<woodchips@rochester.rr.com> said:

> Arthur G <gorramfreak@gmail.com> wrote in message <7d356194-01f0-
> 472f-93d1-04bdad5a1e64@60g2000hsy.googlegroups.com>...
>> On Feb 22, 6:05=A0pm, "Dejun Wang" <dejunw...@yahoo.com> wrote:
>>> Hi, I have a polynomial in the following form:
>>> H(z)=3D[z^4+a3*z^3+a2*z^2+a1*z+a0]/
>>> [z^5+b4*z^4+b3*z^3+b2*z^2+b1*z+b0], where a3-a0,b4-b0 are
>>> known.
>>> I want to obtain a factorized polynomial in the form of
>>> H(z)=3DA/(z-p0)+B/(z-p1)+C/(z-p2)+D/(z-p3)+E/(z-p4), I know
>>> I can use roots to get p0-p5, but is there a function that
>>> I can use to get the value of A,B,C,D,E? Or do I need to
>>> create my own symbolic equations to solve this?
>>> 
>>> Thanks.
>> 
>> residue is the function you want.
> 
> But don't expect success. No matter what,
> it will need to factor a symbolic polynomial
> of the 5th degree with symbolic coefficients.
> 
> Its not gonna work.
> 
> John

Just to clarify, if numerical values are known for
a0-a3 and b0-b4, then residue will give you an
(approximate) numerical solution to the partial
fraction decomposition. That was my interpretation
of the OP's problem statement.

--Arthur
>