2014-11-03 16:16 UTC−06:00, Jori Mantysalo <[email protected]>: > A bug?
It depends on people. You might find a lot of thread in sage-support/sage-devel/ask.sagemath.org about that. The main recurrent problem is that there is no support in Sage for a ring included in the mathematical RR (= the set of reals) that would contains QQbar and most constants (e, pi, cos(p/q), ...) and which would have exact comparisons. The main problem is that it is tricky to get a ring large enough to be useful and small enough for equality to be decidable. >Or have I misunderstood something? I think so, in the symbolic ring (the parent of log(10)) the comparison is *very* special. sage: cmp(cos(1), log(5)) 1 sage: cmp(cos(1).n(20), log(5).n(20)) -1 One way to get it almost right is to avoid the symbolic ring with sage: l = RLF(log(10)) But be careful that even with RLF (the real lazy field) the comparison might be wrong as the comparison is only checked up to finite fixed precision. Vincent -- You received this message because you are subscribed to the Google Groups "sage-support" 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-support. For more options, visit https://groups.google.com/d/optout.
