Um, Sorry! In preparation for converting to symmetric polynomials I had used an iterated polynomial ring
Rt = QQ['t'] Ry = Rt['y1,y2,y3'] R = Ry['x1,x2,x3'] and the fraction field of the ring R is not smart enough to divide by x1-x2 in general. If you use the polynomial ring S = QQ['x1,x2,x3,y1,y2,y3,t'] then "symmetric polynomial" means literally symmetric in all 7 variables x1 through t, which is not what you want. So to convert to symmetric polynomials you will need make polynomial rings with only x's (resp. only y's) as variables and then get your coefficients into these rings and only then use from_polynomial from symmetric functions. --Mark > > Someone correct me if I am ignorant, but > > even after fixing syntax errors, the problem will be that multivariate > > polynomials > > don't know when they are divisible by things like x_i - x_j. > > Really? > > sage: P > Multivariate Polynomial Ring in x, y over Rational Field > sage: P.inject_variables() > Defining x, y > sage: (x^3-y^3)/(x-y) > x^2 + x*y + y^2 > sage: parent((x^3-y^3)/(x-y)) > Fraction Field of Multivariate Polynomial Ring in x, y over Rational Field > sage: P((x^3-y^3)/(x-y)) # this wqill actually be a polynomial > x^2 + x*y + y^2 > sage: Q = PowerSeriesRing(QQ, 'x,y') > sage: Q.inject_variables() > Defining x, y > sage: Q((x^3-y^3)/(x-y)) > /scratch/sage-6.1.1/local/lib/python2.7/site-packages/sage/rings/multi_power_series_ring_element.py:541: > ******************************************************************************** > Warning: Comparison of power series may be wrong if certain > coefficients are zero. The padded_list method can be used to give > correct comparisons. > This issue is being tracked at http://trac.sagemath.org/sage_trac/ticket/9457. > ******************************************************************************** > x^2 + x*y + y^2 + O(x, y)^11 > > Best regards, > Darij > > -- > You received this message because you are subscribed to the Google Groups > "sage-combinat-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-combinat-devel+unsubscr...@googlegroups.com. > To post to this group, send email to sage-combinat-devel@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-combinat-devel. > For more options, visit https://groups.google.com/groups/opt_out. > > -- You received this message because you are subscribed to the Google Groups "sage-combinat-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-combinat-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-combinat-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-combinat-devel. For more options, visit https://groups.google.com/groups/opt_out.
