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apply modular filter to gcd functors

This commit is contained in:
Michael Hemmer 2008-09-26 14:52:49 +00:00
parent 1ca86be74c
commit b6aa6d8644
2 changed files with 45 additions and 25 deletions
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60
Polynomial/include/CGAL/Polynomial/Algebraic_structure_traits.h
View File

@ -190,29 +190,43 @@ class Polynomial_algebraic_structure_traits_base< POLY, Unique_factorization_dom
public:
typedef Unique_factorization_domain_tag Algebraic_category;
class Gcd
: public std::binary_function< POLY, POLY, POLY > {
public:
POLY operator()( const POLY& x, const POLY& y ) const {
typedef Algebraic_structure_traits<POLY> AST;
typename AST::Integral_division idiv;
typename AST::Unit_part upart;
// First: the extreme cases and negative sign corrections.
if (x == POLY(0)) {
if (y == POLY(0))
return POLY(0);
return idiv(y,upart(y));
}
if (y == POLY(0))
return idiv(x,upart(x));
return CGALi::gcd(x,y);
}
CGAL_IMPLICIT_INTEROPERABLE_BINARY_OPERATOR( POLY )
};
class Gcd
: public std::binary_function< POLY, POLY, POLY > {
typedef typename Polynomial_traits_d<POLY>::Multivariate_content Mcontent;
typedef typename Mcontent::result_type ICoeff;
ICoeff gcd_help(const ICoeff& x, const ICoeff& y, Field_tag) const {
return ICoeff(1);
}
ICoeff gcd_help(const ICoeff& x, const ICoeff& y,
Unique_factorization_domain_tag) const {
return CGAL::gcd(x,y);
}
public:
POLY operator()( const POLY& x, const POLY& y ) const {
typedef Algebraic_structure_traits<POLY> AST;
typename AST::Integral_division idiv;
typename AST::Unit_part upart;
// First: the extreme cases and negative sign corrections.
if (CGAL::is_zero(x)) {
if (CGAL::is_zero(y))
return POLY(0);
return idiv(y,upart(y));
}
if (CGAL::is_zero(y))
return idiv(x,upart(x));
if (CGALi::may_have_common_factor(x,y))
return CGALi::gcd(x,y);
else{
typename Algebraic_structure_traits<ICoeff>::Algebraic_category category;
return POLY(gcd_help(Mcontent()(x),Mcontent()(y), category));
}
}
CGAL_IMPLICIT_INTEROPERABLE_BINARY_OPERATOR( POLY )
};
};
// Clone this for a EuclideanRing

10
Polynomial/include/CGAL/Polynomial_traits_d.h
View File

@ -1111,9 +1111,15 @@ public:
:public std::binary_function<Polynomial_d, Polynomial_d, Polynomial_d> {
Polynomial_d
operator()(const Polynomial_d& p, const Polynomial_d& q) const {
if (CGAL::is_zero(p) && CGAL::is_zero(q))
if (CGAL::is_zero(p) && CGAL::is_zero(q)){
return Polynomial_d(0);
return CGALi::gcd_utcf(p,q);
}
// apply modular filter first
if (CGALi::may_have_common_factor(p,q)){
return CGALi::gcd_utcf(p,q);
}else{
return Polynomial_d(1);
}
}
};