Ralf Stephan wrote: > Do I understand it right that then I can coerce a real to a complex > ball and always back to a real without raising an exception?
Coerce, no; convert, yes, I think (assuming that by "a real" you mean "an element of a RealField"), but that's an implementation detail, not something you should rely on. > It does not work with interval fields: > sage: RR(CIF(1)) > 1.00000000000000 > sage: RR(CIF(1/7)) > ... > TypeError: unable to convert '0.1428571428571429?' to a real number But here, you aren't converting back something that was obtained by converting a floating-point number. Is isn't going to work in this case, even with ball fields. And unlike ball fields, interval fields do round floating-point numbers to the interval field precision, so that converting back is not possible in general. -- Marc -- 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 sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
