move type Modular into Modular_arithmetic/Modular_type.h

#include Modular.h to gain CGAL support
This commit is contained in:
Michael Hemmer 2007-03-28 10:30:03 +00:00
parent 5da9da84a8
commit 072bb18304
3 changed files with 302 additions and 295 deletions

1
.gitattributes vendored
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@ -1410,6 +1410,7 @@ Modular_arithmetic/doc_tex/Modular_arithmetic_ref/Modularizable.tex -text
Modular_arithmetic/doc_tex/Modular_arithmetic_ref/intro.tex -text
Modular_arithmetic/doc_tex/Modular_arithmetic_ref/main.tex -text
Modular_arithmetic/examples/Modular_arithmetic/modular_filter.cpp -text
Modular_arithmetic/include/CGAL/Modular_arithmetic/Modular_type.h -text
Modular_arithmetic/test/Modular_arithmetic/Modular_traits.C -text
Nef_2/demo/Nef_2/filtered_homogeneous_data/complex.nef -text svneol=native#application/octet-stream
Nef_2/demo/Nef_2/filtered_homogeneous_data/symmdif.nef -text svneol=native#application/octet-stream

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@ -7,305 +7,13 @@
types.
*/
#ifndef CGAL_MODULAR_H
#define CGAL_MODULAR_H 1
#include <CGAL/basic.h>
#include <cfloat>
#include <CGAL/Modular_arithmetic/Modular_type.h>
namespace CGAL {
class Modular;
Modular operator + (const Modular&);
Modular operator - (const Modular&);
Modular operator + (const Modular&, const Modular&);
Modular operator - (const Modular&, const Modular&);
Modular operator * (const Modular&, const Modular&);
Modular operator / (const Modular&, const Modular&);
std::ostream& operator << (std::ostream& os, const Modular& p);
std::istream& operator >> (std::istream& is, Modular& p);
/*! \ingroup CGAL_Modular_traits
* \brief This class represents the Field Z mod p.
*
* This class uses the type double for representation.
* Therefore the value of p is restricted to primes less than 2^26.
* By default p is set to 67111067.
*
* It provides the standard operators +,-,*,/ as well as in&output.
*
* \see Modular_traits
*/
class Modular{
public:
typedef Modular Self;
typedef Modular NT;
private:
static const double CST_CUT = ((3.0*(1<<30))*(1<<21));
private:
static int prime_int;
static double prime;
static double prime_inv;
/* Quick integer rounding, valid if a<2^51. for double */
static inline
double MOD_round (double a){
#ifdef LiS_HAVE_LEDA
return ( (a + CST_CUT) - CST_CUT);
#else
// TODO:
// In order to get rid of the volatile double
// one should call:
// CGAL/FPU.h : inline void force_ieee_double_precision()
// the problem is where and when it should be called ?
// and whether on should restore the old behaviour
// since it changes the global behaviour of doubles.
// Note that this code works if LEDA is present, since leda automatically
// changes this behaviour in the desired way.
volatile double b = (a + CST_CUT);
return b - CST_CUT;
#endif
}
/* Big modular reduction (e.g. after multiplication) */
static inline
double MOD_reduce (double a){
return a - prime * MOD_round(a * prime_inv);
}
/* Little modular reduction (e.g. after a simple addition). */
static inline
double MOD_soft_reduce (double a){
double b = 2*a;
return (b>prime) ? a-prime :
((b<-prime) ? a+prime : a);
}
/* -a */
static inline
double MOD_negate(double a){
return MOD_soft_reduce(-a);
}
/* a*b */
static inline
double MOD_mul (double a, double b){
double c = a*b;
return MOD_reduce(c);
}
/* a+b */
static inline
double MOD_add (double a, double b){
double c = a+b;
return MOD_soft_reduce(c);
}
/* a^-1, using Bezout (extended Euclidian algorithm). */
static inline
double MOD_inv (double ri1){
double bi = 0.0;
double bi1 = 1.0;
double ri = prime;
double p, tmp, tmp2;
Real_embeddable_traits<double>::Abs double_abs;
while (double_abs(ri1) != 1.0)
{
p = MOD_round(ri/ri1);
tmp = bi - p * bi1;
tmp2 = ri - p * ri1;
bi = bi1;
ri = ri1;
bi1 = tmp;
ri1 = tmp2;
};
return ri1 * MOD_soft_reduce(bi1); /* Quicker !!!! */
}
/* a/b */
static inline
double MOD_div (double a, double b){
return MOD_mul(a, MOD_inv(b));
}
public:
/*! \brief sets the current prime.
*
* Note that you are going to change a static member!
* \pre p is prime, but we abstained from such a test.
* \pre 0 < p < 2^26
*
*/
static int
set_current_prime(int p){
int old_prime = prime_int;
prime_int = p;
prime = (double)p;
prime_inv = (double)1/prime;
return old_prime;
}
/*! \brief return the current prime. */
static int get_current_prime(){
return prime_int;
}
int get_value() const{
return int(x_);
}
private:
double x_;
public:
//! constructor of Modular, from int
Modular(int n = 0){
x_= MOD_reduce(n);
}
//! constructor of Modular, from long
Modular(long n){
x_= MOD_reduce(n);
}
//! Access operator for x, \c const
const double& x() const { return x_; }
//! Access operator for x
double& x() { return x_; }
Self& operator += (const Self& p2) {
x() = MOD_add(x(),p2.x());
return (*this);
}
Self& operator -= (const Self& p2){
x() = MOD_add(x(),MOD_negate(p2.x()));
return (*this);
}
Self& operator *= (const Self& p2){
x() = MOD_mul(x(),p2.x());
return (*this);
}
Self& operator /= (const Self& p2) {
x() = MOD_div(x(),p2.x());
return (*this);
}
friend Self operator + (const Self&);
friend Self operator - (const Self&);
friend Self operator + (const Self&, const Self&);
friend Self operator - (const Self&, const Self&);
friend Self operator * (const Self&, const Self&);
friend Self operator / (const Self& p1, const Self& p2);
};
inline Modular operator + (const Modular& p1)
{ return p1; }
inline Modular operator - (const Modular& p1){
typedef Modular MOD;
Modular r;
r.x() = MOD::MOD_negate(p1.x());
return r;
}
inline Modular operator + (const Modular& p1,const Modular& p2) {
typedef Modular MOD;
Modular r;
r.x() = MOD::MOD_add(p1.x(),p2.x());
return r;
}
inline Modular operator - (const Modular& p1, const Modular& p2) {
return p1+(-p2);
}
inline Modular operator * (const Modular& p1, const Modular& p2) {
typedef Modular MOD;
Modular r;
r.x() = MOD::MOD_mul(p1.x(),p2.x());
return r;
}
inline Modular operator / (const Modular& p1, const Modular& p2) {
typedef Modular MOD;
Modular r;
r.x() = MOD::MOD_div(p1.x(),p2.x());
return r;
}
inline bool operator == (const Modular& p1, const Modular& p2)
{ return ( p1.x()==p2.x() ); }
inline bool operator != (const Modular& p1, const Modular& p2)
{ return ( p1.x()!=p2.x() ); }
// left hand side
inline bool operator == (int num, const Modular& p)
{ return ( Modular(num) == p );}
inline bool operator != (int num, const Modular& p)
{ return ( Modular(num) != p );}
// right hand side
inline bool operator == (const Modular& p, int num)
{ return ( Modular(num) == p );}
inline bool operator != (const Modular& p, int num)
{ return ( Modular(num) != p );}
// left hand side
inline Modular operator + (int num, const Modular& p2)
{ return (Modular(num) + p2); }
inline Modular operator - (int num, const Modular& p2)
{ return (Modular(num) - p2); }
inline Modular operator * (int num, const Modular& p2)
{ return (Modular(num) * p2); }
inline Modular operator / (int num, const Modular& p2)
{ return (Modular(num)/p2); }
// right hand side
inline Modular operator + (const Modular& p1, int num)
{ return (p1 + Modular(num)); }
inline Modular operator - (const Modular& p1, int num)
{ return (p1 - Modular(num)); }
inline Modular operator * (const Modular& p1, int num)
{ return (p1 * Modular(num)); }
inline Modular operator / (const Modular& p1, int num)
{ return (p1 / Modular(num)); }
// I/O
inline std::ostream& operator << (std::ostream& os, const Modular& p) {
typedef Modular MOD;
os <<"("<< p.x()<<"%"<<MOD::get_current_prime()<<")";
return os;
}
inline std::istream& operator >> (std::istream& is, Modular& p) {
typedef Modular MOD;
char ch;
int prime;
is >> p.x();
is >> ch; // read the %
is >> prime; // read the prime
CGAL_precondition(prime==MOD::get_current_prime());
return is;
}
CGAL_BEGIN_NAMESPACE
/*! \brief Specialization of CGAL::NT_traits for \c Modular, which is a model
* of the \c Field concept.
@ -317,7 +25,7 @@ struct Algebraic_structure_traits<Modular>
typedef CGAL::Tag_true Is_exact;
};
}///namespace CGAL
CGAL_END_NAMESPACE
#endif //#ifnedef CGAL_MODULAR_H 1

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@ -0,0 +1,298 @@
#include <CGAL/basic.h>
#include <cfloat>
CGAL_BEGIN_NAMESPACE
class Modular;
Modular operator + (const Modular&);
Modular operator - (const Modular&);
Modular operator + (const Modular&, const Modular&);
Modular operator - (const Modular&, const Modular&);
Modular operator * (const Modular&, const Modular&);
Modular operator / (const Modular&, const Modular&);
std::ostream& operator << (std::ostream& os, const Modular& p);
std::istream& operator >> (std::istream& is, Modular& p);
/*! \ingroup CGAL_Modular_traits
* \brief This class represents the Field Z mod p.
*
* This class uses the type double for representation.
* Therefore the value of p is restricted to primes less than 2^26.
* By default p is set to 67111067.
*
* It provides the standard operators +,-,*,/ as well as in&output.
*
* \see Modular_traits
*/
class Modular{
public:
typedef Modular Self;
typedef Modular NT;
private:
static const double CST_CUT = ((3.0*(1<<30))*(1<<21));
private:
static int prime_int;
static double prime;
static double prime_inv;
/* Quick integer rounding, valid if a<2^51. for double */
static inline
double MOD_round (double a){
#ifdef LiS_HAVE_LEDA
return ( (a + CST_CUT) - CST_CUT);
#else
// TODO:
// In order to get rid of the volatile double
// one should call:
// CGAL/FPU.h : inline void force_ieee_double_precision()
// the problem is where and when it should be called ?
// and whether on should restore the old behaviour
// since it changes the global behaviour of doubles.
// Note that this code works if LEDA is present, since leda automatically
// changes this behaviour in the desired way.
volatile double b = (a + CST_CUT);
return b - CST_CUT;
#endif
}
/* Big modular reduction (e.g. after multiplication) */
static inline
double MOD_reduce (double a){
return a - prime * MOD_round(a * prime_inv);
}
/* Little modular reduction (e.g. after a simple addition). */
static inline
double MOD_soft_reduce (double a){
double b = 2*a;
return (b>prime) ? a-prime :
((b<-prime) ? a+prime : a);
}
/* -a */
static inline
double MOD_negate(double a){
return MOD_soft_reduce(-a);
}
/* a*b */
static inline
double MOD_mul (double a, double b){
double c = a*b;
return MOD_reduce(c);
}
/* a+b */
static inline
double MOD_add (double a, double b){
double c = a+b;
return MOD_soft_reduce(c);
}
/* a^-1, using Bezout (extended Euclidian algorithm). */
static inline
double MOD_inv (double ri1){
double bi = 0.0;
double bi1 = 1.0;
double ri = prime;
double p, tmp, tmp2;
Real_embeddable_traits<double>::Abs double_abs;
while (double_abs(ri1) != 1.0)
{
p = MOD_round(ri/ri1);
tmp = bi - p * bi1;
tmp2 = ri - p * ri1;
bi = bi1;
ri = ri1;
bi1 = tmp;
ri1 = tmp2;
};
return ri1 * MOD_soft_reduce(bi1); /* Quicker !!!! */
}
/* a/b */
static inline
double MOD_div (double a, double b){
return MOD_mul(a, MOD_inv(b));
}
public:
/*! \brief sets the current prime.
*
* Note that you are going to change a static member!
* \pre p is prime, but we abstained from such a test.
* \pre 0 < p < 2^26
*
*/
static int
set_current_prime(int p){
int old_prime = prime_int;
prime_int = p;
prime = (double)p;
prime_inv = (double)1/prime;
return old_prime;
}
/*! \brief return the current prime. */
static int get_current_prime(){
return prime_int;
}
int get_value() const{
return int(x_);
}
private:
double x_;
public:
//! constructor of Modular, from int
Modular(int n = 0){
x_= MOD_reduce(n);
}
//! constructor of Modular, from long
Modular(long n){
x_= MOD_reduce(n);
}
//! Access operator for x, \c const
const double& x() const { return x_; }
//! Access operator for x
double& x() { return x_; }
Self& operator += (const Self& p2) {
x() = MOD_add(x(),p2.x());
return (*this);
}
Self& operator -= (const Self& p2){
x() = MOD_add(x(),MOD_negate(p2.x()));
return (*this);
}
Self& operator *= (const Self& p2){
x() = MOD_mul(x(),p2.x());
return (*this);
}
Self& operator /= (const Self& p2) {
x() = MOD_div(x(),p2.x());
return (*this);
}
friend Self operator + (const Self&);
friend Self operator - (const Self&);
friend Self operator + (const Self&, const Self&);
friend Self operator - (const Self&, const Self&);
friend Self operator * (const Self&, const Self&);
friend Self operator / (const Self& p1, const Self& p2);
};
inline Modular operator + (const Modular& p1)
{ return p1; }
inline Modular operator - (const Modular& p1){
typedef Modular MOD;
Modular r;
r.x() = MOD::MOD_negate(p1.x());
return r;
}
inline Modular operator + (const Modular& p1,const Modular& p2) {
typedef Modular MOD;
Modular r;
r.x() = MOD::MOD_add(p1.x(),p2.x());
return r;
}
inline Modular operator - (const Modular& p1, const Modular& p2) {
return p1+(-p2);
}
inline Modular operator * (const Modular& p1, const Modular& p2) {
typedef Modular MOD;
Modular r;
r.x() = MOD::MOD_mul(p1.x(),p2.x());
return r;
}
inline Modular operator / (const Modular& p1, const Modular& p2) {
typedef Modular MOD;
Modular r;
r.x() = MOD::MOD_div(p1.x(),p2.x());
return r;
}
inline bool operator == (const Modular& p1, const Modular& p2)
{ return ( p1.x()==p2.x() ); }
inline bool operator != (const Modular& p1, const Modular& p2)
{ return ( p1.x()!=p2.x() ); }
// left hand side
inline bool operator == (int num, const Modular& p)
{ return ( Modular(num) == p );}
inline bool operator != (int num, const Modular& p)
{ return ( Modular(num) != p );}
// right hand side
inline bool operator == (const Modular& p, int num)
{ return ( Modular(num) == p );}
inline bool operator != (const Modular& p, int num)
{ return ( Modular(num) != p );}
// left hand side
inline Modular operator + (int num, const Modular& p2)
{ return (Modular(num) + p2); }
inline Modular operator - (int num, const Modular& p2)
{ return (Modular(num) - p2); }
inline Modular operator * (int num, const Modular& p2)
{ return (Modular(num) * p2); }
inline Modular operator / (int num, const Modular& p2)
{ return (Modular(num)/p2); }
// right hand side
inline Modular operator + (const Modular& p1, int num)
{ return (p1 + Modular(num)); }
inline Modular operator - (const Modular& p1, int num)
{ return (p1 - Modular(num)); }
inline Modular operator * (const Modular& p1, int num)
{ return (p1 * Modular(num)); }
inline Modular operator / (const Modular& p1, int num)
{ return (p1 / Modular(num)); }
// I/O
inline std::ostream& operator << (std::ostream& os, const Modular& p) {
typedef Modular MOD;
os <<"("<< p.x()<<"%"<<MOD::get_current_prime()<<")";
return os;
}
inline std::istream& operator >> (std::istream& is, Modular& p) {
typedef Modular MOD;
char ch;
int prime;
is >> p.x();
is >> ch; // read the %
is >> prime; // read the prime
CGAL_precondition(prime==MOD::get_current_prime());
return is;
}
CGAL_END_NAMESPACE