Package edu.jas.gbufd

Class PolyGBUtil


  • public class PolyGBUtil
    extends java.lang.Object
    Package gbufd utilities.
    Author:
    Heinz Kredel
    • Method Detail

      • isResultant

        public static <C extends GcdRingElem<C>> boolean isResultant​(GenPolynomial<C> A,
                                                                     GenPolynomial<C> B,
                                                                     GenPolynomial<C> r)
        Test for resultant.
        Parameters:
        A - generic polynomial.
        B - generic polynomial.
        r - generic polynomial.
        Returns:
        true if res(A,B) isContained in ideal(A,B), else false.
      • topPseudoRemainder

        public static <C extends RingElem<C>> GenPolynomial<C> topPseudoRemainder​(java.util.List<GenPolynomial<C>> A,
                                                                                  GenPolynomial<C> P)
        Top pseudo reduction wrt the main variables.
        Parameters:
        P - generic polynomial.
        A - list of generic polynomials sorted according to appearing main variables.
        Returns:
        top pseudo remainder of P wrt. A for the appearing variables.
      • topCoefficientPseudoRemainder

        public static <C extends RingElem<C>> GenPolynomial<C> topCoefficientPseudoRemainder​(java.util.List<GenPolynomial<C>> A,
                                                                                             GenPolynomial<C> P)
        Top coefficient pseudo remainder of the leading coefficient of P wrt A in the main variables.
        Parameters:
        P - generic polynomial in n+1 variables.
        A - list of generic polynomials in n variables sorted according to appearing main variables.
        Returns:
        pseudo remainder of the leading coefficient of P wrt A.
      • zeroDegrees

        public static <C extends RingElem<C>> java.util.List<GenPolynomial<C>> zeroDegrees​(java.util.List<GenPolynomial<C>> A)
        Extract polynomials with degree zero in the main variable.
        Parameters:
        A - list of generic polynomials in n variables.
        Returns:
        Z = [a_i] with deg(a_i,x_n) = 0 and in n-1 variables.
      • subRing

        public static <C extends GcdRingElem<C>> java.util.List<GenPolynomial<C>> subRing​(java.util.List<GenPolynomial<C>> A)
        Subring generators.
        Parameters:
        A - list of polynomials in n variables.
        Returns:
        a Groebner base of polynomials in m > n variables generating the subring of K[A].
      • subRingMember

        public static <C extends GcdRingElem<C>> boolean subRingMember​(java.util.List<GenPolynomial<C>> A,
                                                                       GenPolynomial<C> g)
        Subring membership.
        Parameters:
        A - Groebner base of polynomials in m > n variables generating the subring of elements of K[A].
        g - polynomial in n variables.
        Returns:
        true, if g \in K[A], else false.
      • subRingAndMember

        public static <C extends GcdRingElem<C>> boolean subRingAndMember​(java.util.List<GenPolynomial<C>> A,
                                                                          GenPolynomial<C> g)
        Subring and membership test.
        Parameters:
        A - list of polynomials in n variables.
        g - polynomial in n variables.
        Returns:
        true, if g \in K[A], else false.
      • chineseRemainderTheorem

        public static <C extends GcdRingElem<C>> GenPolynomial<C> chineseRemainderTheorem​(java.util.List<java.util.List<GenPolynomial<C>>> F,
                                                                                          java.util.List<GenPolynomial<C>> A)
        Chinese remainder theorem.
        Parameters:
        F - = ( F_i ) list of list of polynomials in n variables.
        A - = ( f_i ) list of polynomials in n variables.
        Returns:
        p \in \Cap_i (f_i + ideal(F_i)) if it exists, else null.
      • isChineseRemainder

        public static <C extends GcdRingElem<C>> boolean isChineseRemainder​(java.util.List<java.util.List<GenPolynomial<C>>> F,
                                                                            java.util.List<GenPolynomial<C>> A,
                                                                            GenPolynomial<C> h)
        Is Chinese remainder.
        Parameters:
        F - = ( F_i ) list of list of polynomials in n variables.
        A - = ( f_i ) list of polynomials in n variables.
        h - polynomial in n variables.
        Returns:
        true if h \in \Cap_i (f_i + ideal(F_i)), else false.
      • CRTInterpolation

        public static <C extends GcdRingElem<C>> GenPolynomial<C> CRTInterpolation​(GenPolynomialRing<C> fac,
                                                                                   java.util.List<java.util.List<C>> E,
                                                                                   java.util.List<C> V)
        Chinese remainder theorem, interpolation.
        Parameters:
        fac - polynomial ring over K in n variables.
        E - = ( E_i ), E_i = ( e_ij ) list of list of elements of K, the evaluation points.
        V - = ( f_i ) list of elements of K, the evaluation values.
        Returns:
        p \in K[X1,...,Xn], with p(E_i) = f_i, if it exists, else null.