 
 
 
 
 
 
 
  
Let  be a polynomial and be maxroot the maximal modulus of
the root of
 be a polynomial and be maxroot the maximal modulus of
the root of  . From
. From  we may derive a polynomial
 we may derive a polynomial  such that the
roots of
 such that the
roots of  have a modulus lower or equal to 1 and if
 have a modulus lower or equal to 1 and if  is a root
of
 is a root
of  then maxroot
 then maxroot is a root of
 is a root of  .
The calculation of the coefficients of
.
The calculation of the coefficients of  may be done with the
procedure
 may be done with the
procedure 
 
int Unit_Polynom(int Degree,INTERVAL_VECTOR &Coeff,
                double maxroot,INTERVAL_VECTOR &CoeffU)
 
where Coeff are the coefficients of  and CoeffU the
coefficients of
 and CoeffU the
coefficients of  . This procedure returns 1 if the calculation has
been successfull, 0 otherwise.
. This procedure returns 1 if the calculation has
been successfull, 0 otherwise.