Thanks for this clarification. I guess my follow up question would be do we want infinity to be real in this sense or is that just a byproduct of its implementation? I don't know all the uses for infinity that other sage users have, but certainly from the perspective of the Riemann sphere it's a bit odd since CC(infinity,0), CC(0, infinity) and CC(infinity, infinity) are all distinct in sage, giving us 3 different complex infinities. I'm not particularly picking on CC, since infinity*I and infinity are also not equal.
On Thursday, October 3, 2013 2:10:19 PM UTC-4, Michael Orlitzky wrote: > > On 10/03/2013 11:54 AM, Greg Laun wrote: > > Out of curiosity, I decided to ask sage what it thought the imaginary > > part of infinity was. I'm not quite sure that this should return 0. > > Mathematica returns Indeterminate, which seems like a better answer to > me. > > > > Has this been discussed elsewhere? > > > > > The CC constructor takes the real/imaginary parts separately. So if you > want (0, infinity) or (infinity, infinity) or something in between, you > can do that: > > sage: imag( CC(Infinity, Infinity) ) > +infinity > > Sage's infinity is essentially real, if for no other reason than, > > sage: infinity.numerical_approx().base_ring() > Real Field with 53 bits of precision > > The actual semantics are explained in, > > http://www.sagemath.org/doc/reference/rings/sage/rings/infinity.html > > -- 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 http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/groups/opt_out.
