On 04/05/2016 01:03 PM, William Stein wrote: > > I think we should change is_prime for rational numbers, since people > get confused by this so much. > > How? Pretty much any change at all would be better than the current > situation. Options I can think of: > > - make is_prime([rational]) raise an error and tell the user what to do > - look at what is_prime([rational]) does in Pari, Mathematica, etc., > and do the same thing > - make is_prime([rational]) return is_prime(ZZ([rational])) -- this > would be a change that would potentially silently break some code, but > is what many people expect. >
Why not have two? The problem is that everyone knows what is_prime() is supposed to do -- it's supposed to tell you if a number is prime. Except it doesn't always do that, it does some abstract mumbo jumbo whenever you don't have an integer (even if you do "have an integer"). We could leave is_prime() for humans, and have is_prime_in_ring() for people who know what that means. -- 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 sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at https://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
