cgal/Polynomial/doc_tex/Polynomial_ref/PolynomialTraits_d_Polynomi...

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\begin{ccRefConcept}{PolynomialTraits_d::PolynomialSubresultants}
\textbf{Note:} This functor is optional!
\ccDefinition
Computes the polynomial subresultant of two polynomials $p$ and $q$ of
type \ccc{PolynomialTraits_d::Polynomial_d} with respect to outermost variable.
Let
$p=\ccSum{i=0,\ldots,n}{} p_i x^i$ and
$q=\ccSum{i=0,\ldots,m}{} q_i x^i$, where $x$
is the outermost variable.
The $i$-th subresultant (with $i=0,\ldots,\min\{n,m\}$) is defined by
\begin{ccTexOnly}
\begin{eqnarray*}
\mathrm{Sres}_i(p,q)&=&\det \left(\begin{array}{ccccccc}
p_n & \ldots &&\ldots& p_{2i-m+2}&x^{m-i-1}p \\
&\ddots&&&\vdots&\vdots\\
&&p_n&\ldots&p_{i+1}&p\\
q_m & \ldots &&\ldots & q_{2i-n+2}&x^{n-i-1}q \\
&\ddots&&&\vdots&\vdots\\
&&q_m&\ldots&q_{i+1}&q
\end{array}\right)
\end{eqnarray*}
\end{ccTexOnly}
\begin{ccHtmlOnly}
<CENTER>
<IMG BORDER=0 SRC="./subresultant_def.gif" ALIGN=middle ALT="Subresultants">
</CENTER>
\end{ccHtmlOnly}
where $p_i$ and $q_i$ are set to zero if $i<0$.
In the case that $n=m$, $\mathrm{Sres_n}$ is set to $q$.
The result is written in an output range, starting with the $0$-th subresultant
$\mathrm{Sres}_0(p,q)$
(aka as the resultant of $p$ and $q$).
\ccRefines
\ccc{AdaptableBinaryFunction}\\
\ccc{CopyConstructible}\\
\ccc{DefaultConstructible}\\
\ccCreationVariable{fo}
\ccOperations
\ccMethod{template<typename OutputIterator>
OutputIterator operator()(Polynomial_d p,
Polynomial_d q,
OutputIterator out);}
{ computes the polynomial subresultants of $p$ and $q$,
with respect to the outermost variable. Each element is of type
\ccc{PolynomialTraits_d::Polynomial_d}.}
\ccMethod{template<typename OutputIterator>
OutputIterator operator()(Polynomial_d p,
Polynomial_d q,
OutputIterator out,
int i);}
{ computes the polynomial subresultants of $p$ and $q$,
with respect to the variable $x_i$.}
%\ccHasModels
\ccSeeAlso
\ccRefIdfierPage{Polynomial_d}\\
\ccRefIdfierPage{PolynomialTraits_d}\\
\ccRefIdfierPage{PolynomialTraits_d::Resultant}\\
\ccRefIdfierPage{PolynomialTraits_d::PrincipalSubresultants}\\
\ccRefIdfierPage{PolynomialTraits_d::PolynomialSubresultantsWithCofactors}\\
\ccRefIdfierPage{PolynomialTraits_d::SturmHabichtSequence}\\
\end{ccRefConcept}