Révision 170 pobysoPythonSage/src/sageSLZ/sageSLZ.sage

sageSLZ.sage (revision 170)
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    # Coefficients are issued in the increasing power order.
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    ratPolyCoefficients = ratPolyOfInt.coefficients()
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    # Print the reversed list for debugging.
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    print
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    print "Rational polynomial coefficients:", ratPolyCoefficients[::-1]
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    # Build the list of number we compute the lcm of.
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    coefficientDenominators = sro_denominators(ratPolyCoefficients)
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    print "Coefficient denominators:", coefficientDenominators
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    coefficientDenominators.append(2^precision)
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    coefficientDenominators.append(2^(targetHardnessToRound + 1))
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    coefficientDenominators.append(2^(targetHardnessToRound))
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    leastCommonMultiple = lcm(coefficientDenominators)
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    # Compute the expression corresponding to the new polynomial
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    coefficientNumerators =  sro_numerators(ratPolyCoefficients)
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    #print coefficientNumerators
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    polynomialExpression = 0
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    power = 0
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    # Iterate over two lists at the same time, stop when the shorter is
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    # exhausted.
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    # Iterate over two lists at the same time, stop when the shorter
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    # (is this case coefficientsNumerators) is
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    # exhausted. Both lists are ordered in the order of increasing powers
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    # of variable1.
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    for numerator, denominator in \
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                        zip(coefficientNumerators, coefficientDenominators):
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        multiplicator = leastCommonMultiple / denominator
......
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        power +=1
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    polynomialExpression += - variable2
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    return (IP(polynomialExpression),
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            leastCommonMultiple / 2^precision, # 2^K or N.
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            leastCommonMultiple / 2^(targetHardnessToRound + 1), # tBound
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            leastCommonMultiple / 2^precision, # 2^K aka N.
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            #leastCommonMultiple / 2^(targetHardnessToRound + 1), # tBound
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            leastCommonMultiple / 2^(targetHardnessToRound), # tBound
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            leastCommonMultiple) # If we want to make test computations.
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# End slz_ratPoly_of_int_to_poly_for_coppersmith
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# End slz_rat_poly_of_int_to_poly_for_coppersmith
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def slz_rat_poly_of_rat_to_rat_poly_of_int(ratPolyOfRat, 


  		





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                                          precision):


  		





  ......




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        polynomialField(ratPolyOfRat.subs({polynomialVariable : \


  		





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                                   polynomialVariable/2^(precision-1)}))


  		





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    # Return a tuple:


  		





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    # - the bivariate integer polynomial in (i,j);


  		





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    # - 2^K


  		





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# End slz_rat_poly_of_rat_to_rat_poly_of_int


  		





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