On Wednesday, December 18, 2013 9:58:15 AM UTC-8, vdelecroix wrote: > > Users of polynomials should worry about the coefficient ring. What do > someone should expect of > > sage: (6*x^2 - 12).factor() > > The answers are different in ZZ[x], QQ[x] and RR[x]. For a symbolic > polynomial there is no way to make it coherent... > It's worse: SR isn't even an exact ring (and it has zero divisors; seehttp://trac.sagemath.org/ticket/11126#comment:2) , so a lot of polynomial arithmetic you'd normally expect to work, doesn't in general.
So yes we can define polynomial rings with coefficients in SR: sage: SR['x'] Univariate Polynomial Ring in x over Symbolic Ring sage: (1+sin(2))*x-2.3 (sin(2) + 1)*x - 2.30000000000000 but any nontrivial computation in it will be problematic (I take this as definition of nontrivial here). > And I guess a long term goal of Sage would be to make it disappear. > It IS good for some things: integration strategies and some symbolic differential equation solving methods do benefit from the loose approach that SR takes with mathematical expressions. I think a more attainable goal is to allow the user to avoid SR in as many cases as possible. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/groups/opt_out.
