cgal/Polynomial/doc_tex/Polynomial_ref/PolynomialTraits_d_Principa...

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\begin{ccRefConcept}{PolynomialTraits_d::Principal_subresultants}
\ccDefinition
Computes the principal subresultant of two polynomials $f$ and $g$ of
type \ccc{PolynomialTraits_d::Polynomial_d}
with respect a certain variable $x_i$.
The principal subresultants are also known as {\it scalar} subresultants.
The $j$th such principal subresultant is defined to be the coefficient
of $x_i^j$ in the $j$-th subresultant polynomial of $f$ and $g$.
Since the degree of the $j$-th subresultant polynomial is at most $j$,
this principal coefficients are sometimes called the
{\tt formal leading coefficients} (``formal'' because they might vanish).
The result is written in an output range,
starting with the $0$th principal subresultant
(aka as the resultant of $f$ and $g$).
\ccOperations
\ccMethod{template<typename OutputIterator>
OutputIterator operator()(Polynomial_d f,
Polynomial_d g,
OutputIterator out);}
{ computes the principal subresultants of $f$ and $g$,
with respect to the outermost variable. Each element is of type
\ccc{PolynomialTraits_d::Coefficient_type}.}
\ccMethod{template<typename OutputIterator>
OutputIterator operator()(Polynomial_d f,
Polynomial_d g,
OutputIterator out,
int i);}
{ computes the principal subresultants of $f$ and $g$,
with respect to the variable $x_i$.}
%\ccHasModels
\ccSeeAlso
\ccRefIdfierPage{Polynomial_d}\\
\ccRefIdfierPage{PolynomialTraits_d}\\
\end{ccRefConcept}