liblinbox-dev 1.1.6~rc0-4.1 / usr / include / linbox / field / ntl-ZZ_pX.h

#ifndef __FIELD_NTL_ZZ_pX_H
#define __FIELD_NTL_ZZ_pX_H

/** linbox/field/ntl-ZZ_pX.h
  * Daniel Roche, August 2005
  */

#include <linbox/field/unparametric.h>
#include <linbox/field/ntl-ZZ_p.h>
#include <linbox/integer.h>
#include <vector>
#include <NTL/ZZ_pX.h>

namespace LinBox { // namespace in which all LinBox code resides

/** Ring (in fact, a unique factorization domain) of polynomial with
  * coefficients in class NTL_ZZ_p (integers mod a wordsize prime).
  * All the same functions as any other ring, with the addition of:
  * Coeff (type), CoeffField (type), getCoeffField, setCoeff, getCoeff, 
  * leadCoeff, deg
  */
class NTL_ZZ_pX :public UnparametricField<NTL::ZZ_pX> {
    public:
	typedef NTL_ZZ_p CoeffField;
	typedef NTL::ZZ_p Coeff;
	typedef NTL::ZZ_pX Element;
    
	/** Standard LinBox field constructor.  The paramters here
	  * (prime, exponent) are only used to initialize the coefficient field.
	  */
	NTL_ZZ_pX( const integer& p, size_t e = 1 )
	: UnparametricField<NTL::ZZ_pX>(p, e), _CField(p,e)
	{}
	
	/** Constructor from a coefficient field */
	NTL_ZZ_pX( CoeffField cf ) :_CField(cf) {}

	/** Initialize p to the constant y (p = y*x^0) */
	template <class ANY>
	Element& init( Element& p, const ANY& y ) const {
		Coeff temp;
		_CField.init( temp, y );
		return p = temp;
	}

	/** Initialize p to the constant y (p = y*x^0) */
	Element& init( Element& p, const Coeff& y ) const {
		return p = y;
	}

	/** Initialize p from a vector of coefficients.
	  * The vector should be ordered the same way NTL does it: the front
	  * of the vector corresponds to the trailing coefficients, and the back
	  * of the vector corresponds to the leading coefficients.  That is,
	  * v[i] = coefficient of x^i.
	  */
	template <class ANY>
	Element& init( Element& p, const std::vector<ANY>& v ) const {
		p = 0;
		Coeff temp;
		for( long i = 0; i < (long)v.size(); ++i ) {
			_CField.init( temp, v[ (size_t) i ] );
			if( !_CField.isZero(temp) )
				NTL::SetCoeff( p, i, temp );
		}
		return p;
	}

	/** Initialize p from a vector of coefficients.
	  * The vector should be ordered the same way NTL does it: the front
	  * of the vector corresponds to the trailing coefficients, and the back
	  * of the vector corresponds to the leading coefficients.  That is,
	  * v[i] = coefficient of x^i.
	  */
	Element& init( Element& p, const std::vector<Coeff>& v ) const {
		p = 0;
		for( long i = 0; i < (long)v.size(); ++i )
			NTL::SetCoeff( p, i, v[ (size_t) i ] );
		return p;
	}

	/** Convert p to a vector of coefficients.
	  * The vector will be ordered the same way NTL does it: the front
	  * of the vector corresponds to the trailing coefficients, and the back
	  * of the vector corresponds to the leading coefficients.  That is,
	  * v[i] = coefficient of x^i.
	  */
	template< class ANY >
	std::vector<ANY>& convert( std::vector<ANY>& v, const Element& p ) const
	{
		v.clear();
		ANY temp;
		for( long i = 0; i <= this->deg(p); ++i ) {
			_CField.convert( temp, NTL::coeff( p, i ) );
			v.push_back( temp );
		}
		return v;
	}

	/** Convert p to a vector of coefficients.
	  * The vector will be ordered the same way NTL does it: the front
	  * of the vector corresponds to the trailing coefficients, and the back
	  * of the vector corresponds to the leading coefficients.  That is,
	  * v[i] = coefficient of x^i.
	  */
	std::vector<Coeff>& convert( std::vector<Coeff>& v, const Element& p )
		const
	{
		v.clear();
		for( long i = 0; i <= (long)this->deg(p); ++i )
			v.push_back( NTL::coeff(p,i) );
		return v;
	}

	/** Test if an element equals zero */
	bool isZero( const Element& x ) const {
		return ( (this->deg(x) == 0) && 
		         ( _CField.isZero( NTL::ConstTerm(x) ) ) );
	}

	/** Test if an element equals one */
	bool isOne( const Element& x ) const {
		return ( (this->deg(x) == 0) && 
		         ( _CField.isOne( NTL::ConstTerm(x) ) ) );
	}

	/** The LinBox field for coefficients */
	const CoeffField& getCoeffField() const { return _CField; }

	/** Get the degree of a polynomial 
	  * Unlike NTL, deg(0)=0.
	  */
	size_t deg( const Element& p ) const {
		long temp = NTL::deg(p);
		if( temp == -1 ) return 0;
		else return static_cast<size_t>(temp);
	}

	/** r will be set to the reverse of p. */
	Element& rev( Element& r, const Element& p ) {
		NTL::reverse(r,p);
		return r;
	}

	/** r is itself reversed. */
	Element& revin( Element& r ) {
		return r = NTL::reverse(r);
	}

	/** Get the leading coefficient of this polynomial. */
	Coeff& leadCoeff( Coeff& c, const Element& p ) const {
		c = NTL::LeadCoeff(p);
		return c;
	}

	/** Get the coefficient of x^i in a given polynomial */
	Coeff& getCoeff( Coeff& c, const Element& p, size_t i ) const {
		c = NTL::coeff( p, (long)i );
		return c;
	}

	/** Set the coefficient of x^i in a given polynomial */
	Element& setCoeff( Element& p, size_t i, const Coeff& c ) const {
		NTL::SetCoeff(p,(long)i,c);
		return p;
	}

	/** Get the quotient of two polynomials */
	Element& quo( Element& res, const Element& a, const Element& b ) const {
		NTL::div(res,a,b);
		return res;
	}

	/** a = quotient of a, b */
	Element& quoin( Element& a, const Element& b ) const {
		return a /= b;
	}

	/** Get the remainder under polynomial division */
	Element& rem( Element& res, const Element& a, const Element& b ) const {
		NTL::rem(res,a,b);
		return res;
	}

	/** a = remainder of a,b */
	Element& remin( Element& a, const Element& b ) const {
		return a %= b;
	}

	/** Get the quotient and remainder under polynomial division */
	void quorem( Element& q, Element& r,
	                 const Element& a, const Element& b ) const
	{
		NTL::DivRem(q,r,a,b);
	}

	/** Get characteristic of the field - same as characteristic of 
	  * coefficient field. */
	integer& characteristic( integer& c ) const 
		{ return _CField.characteristic(c); }

	/** Get the cardinality of the field.  Since the cardinality is
	  * infinite, by convention we return -1.
	  */
	integer& cardinality( integer& c ) const 
		{ return c = static_cast<integer>(-1); }
	
	static inline integer getMaxModulus()
		{ return CoeffField::getMaxModulus(); }

    private:
	/** Conversion to scalar types doesn't make sense and should not be
	  * used.  Use getCoeff or leadCoeff to get the scalar values of
	  * specific coefficients, and then convert them using coeffField()
	  * if needed.
	  */
	template< class ANY >
	ANY& convert( ANY& x, const Element& y ) const { return x; }

    	CoeffField _CField;
}; // end of class NTL_ZZ_pX

/** Write a description of the field */
// Oustide of class definition so write(ostream&,const Element&) from
// UnparametricField still works.
template<>
std::ostream& UnparametricField<NTL::ZZ_pX>::write( std::ostream& os ) const {
	return os << "Polynomial ring using NTL::ZZ_pX";
}


} // end of namespace LinBox

#endif // __FIELD_NTL_ZZ_pX_H