Hi, First of all, many thanks to all the Sage development folks. We have a great time in my team using Sage for our research work.
I just wanted to present you with a little problem. With the following code: from sage.symbolic.expression_conversions import polynomial var('x') expression = 4/x # Or any value different from 1. print "Is expression a polynomial? ", expression.is_polynomial(expression.arguments()[0]) We get: Is expression a polynomial? True But if we change "expression = 4/x" to "expression = 1/x" then I get: Is expression a polynomial? False If we try to convert these expressions into a sage.rings.polynomial.polynomial_real_mpfr_dense.PolynomialRealDense with "polynomial(expression, RR)", in both cases I get an error: TypeError: denominator must be a unit We went around what is problem for us with this (insatisfactory) hack: print "Is expression a polynomial? ", \ bool(expression.is_polynomial(expression.arguments()[0]) and (expression.denominator().diff() == 0)) We have this same behaviour on 4.6, 4.61, 4.62 (I have unfortunately not access to previous Sage versions) Linux for Unbuntu precompiled packages used on Ubuntu 10.04 LTS x86, Debian Lenny and Squeeze amd_64 distributions. Two things puzzle us: - why should 4/x (or whatever_different_from_1/x) be considered as a polynomial? - if 4/x should why 1/x should not? I have this same behaviour on 4.6, 4.61, 4.61 (I have unfortunately not access to previous Sage versions) on Linux for Unbuntu precompiled package used on Ubuntu 10.04 LTS x86, Debian Lenny and Squeeze amd_64 distributions. Thanks in advance. Best regards, Serge Torres -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org