You may have noticed that somebody is painfully trying to make comparison compatible with python3.
The semantics of comparison for RealInterval is "every element of A has the given relation to every element of B". This will not change, as many people are saying this is exactly what they want. In my opinion, this is is very bad, as it has almost none of the defining properties of a partial order. Le mercredi 3 mai 2017 09:12:08 UTC+2, Ralf Stephan a écrit : > > Hello, > I understand that balls in general cannot be compared. However, integer > balls have zero size and actually real integer/rational balls can be > compared: > sage: RBF(2)>RBF(1) > True > > This though seems buggy: > sage: BF = RealBallField(precision=2) > sage: BF(1.0000002)>BF(1.0000001) > True > sage: BF(1.0000002)-BF(1.0000001) > [+/- 1.20e-7] > > OTOH, real integers of complex ball type are not comparable at all, > inconsistent with what CC allows: > sage: CC(2)>CC(1) > True > sage: CBF(2)>CBF(1) > ... > TypeError: No order is defined for ComplexBalls. > > But then I would expect CC to raise exceptions for this: > sage: CC(I+1)>CC(I) > True > sage: CC(I-1)>CC(2*I) > False > > With intervals it's not better. While this works: > sage: RealInterval(2)>RealInterval(1) > True > sage: ComplexIntervalFieldElement(2)>ComplexIntervalFieldElement(1) > True > > This should IMO raise exceptions: > sage: RealInterval(1,upper=2)<RealInterval(1.5,upper=2.5) > False > sage: ComplexIntervalFieldElement(1,1)>ComplexIntervalFieldElement(0,2) > True > > This all makes it overly complicated to provide symbolic function services > for these types so which improvements can be made? Where am I missing > something? > > Best, > -- 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.
