Laboratoire de l'Informatique et du Parallélisme » Pobyso

module:: sageSLZ.sage

def slz_compute_reduced_polynomials(reducedMatrix,

                                    knownMonomials,

                                    polynomialRing,

                                    var1Bound,

                                    var2Bound, ):

    """

    From a reduced matrix, holding the coefficients, from a monomials list,

    from the bounds of each variable, compute the corresponding polynomials

    scaled back by dividing by the "right" powers of the variables bounds.

    """

    # TODO: check input arguments.

    if len(knownMonomials) == 0:

        return []

    (var1, var2) = knownMonomials[0].variables()[0:2]

    print "Variable 1:", var1;

    print "Variable 2:", var2

    reducedPolynomials = []

    for matrixRow in reducedMatrix.rows():

        currentExpression = 0

        for colIndex in xrange(0, len(knownMonomials)):

            currentCoefficient = matrixRow[colIndex]

            print knownMonomials[colIndex]

            currentMonomialAsMvp = polynomialRing(knownMonomials[colIndex])

            print "Monomial as multivariate polynomial:", \

            currentMonomialAsMvp, type(currentMonomialAsMvp)

            degreeInVar1 = currentMonomialAsMvp.degree(var1)

            print "Degree in var", var1, ":", degreeInVar1

            degreeInVar2 = currentMonomialAsMvp.degree(var2)

            if degreeInVar1 != 0:

                currentCoefficient  /= (var1Bound^degreeInVar1)

            if degreeInVar2 != 0:

                currentCoefficient /= (var2Bound^degreeInVar2)

            print "Current Expression:", currentExpression

            currentExpression += currentCoefficient * \

                currentMonomialAsMvp

        reducedPolynomials.append(currentExpression)

    return reducedPolynomials 

# End slz_compute_reduced_polynomials