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// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
// Copyright (C) ????-2008 - INRIA
//
// This file must be used under the terms of the CeCILL.
// This source file is licensed as described in the file COPYING, which
// you should have received as part of this distribution. The terms
// are also available at
// http://www.cecill.info/licences/Licence_CeCILL_V2.1-en.txt
function [f]=polfact(p)
// Minmal factors of p
// f=polfact(p)
//
// p : polynomial
// f : vector [f0 f1 ... fn] such that p=prod(f)
// - f0 constant
// - fi polynomial
//!
//
if type(p)>2 then
error(msprintf(gettext("%s: Wrong type for input argument: Polynomial array expected.\n"),"polfact"))
end
if size(p,"*")<>1 then
error(msprintf(gettext("%s: Wrong size for input argument #%d: A polynomial expected.\n"),"polfact",1))
end
if norm(imag(coeff(p)))<>0 then
error(msprintf(gettext("%s: Input argument #%d must be real.\n"),"polfact",1))
end
p=real(p)
n=degree(p);f=coeff(p,n);
if n==0 then return,end
var=varn(p);
r=roots(p);[s,k]=gsort(abs(r));r=r(k)
k=1;
while k<=n do,
if imag(r(k))<>0 then
f=[f,real(poly(r(k:k+1),var))]
k=k+2
else
f=[f,poly(r(k),var)]
k=k+1
end
end
endfunction
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