On 21 December 2015 at 16:40, Volker Braun <vbraun.n...@gmail.com> wrote: > Just to point out the obvious: In Mathematics, "inverting an integer" means > 1/x
Of course it does but no mathematician would ever write that in notation as ~x. > > Though if you want to work with Python ints nothing is stopping you... > > sage: ~2r > -3 > sage: ~int(2) > -3 > sage: ~2 > 1/2 > sage: ~ZZ(2) > 1/2 > > On Monday, December 21, 2015 at 5:22:20 PM UTC+1, Mark Bell wrote: >> >> In Python for an integer x, its invert ~x is defined to be its >> two-complement and is given by -1-x. >> >> On the other hand, in Sage Integers (from sage.rings.integer.Integer) have >> their __invert__ defined to be 1 / self. >> >> Unfortunately this difference is cause several of my Python scripts to >> crash / behave differently. Most notably that under this definition ~0 >> raises a "ZeroDivisionError: Rational division by zero" error. >> >> Looking through the git history it appears that this has been the way >> integers that have been inverted since at least October 2006. Why do sage >> Integers not use the "standard" Python invert? > > -- > 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. -- 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.
