On Wed, Jan 25, 2012 at 7:25 AM, kcrisman <kcris...@gmail.com> wrote: > >> > Probably that should be implemented inside the trigonometric functions >> > code itself, instead of in any of the "simplify"'s. >> >> > What do you think? >> >> +1 >> >> It's indeed annoying that Sage doesn't do this simplification (because >> Maxima doesn't). > > Though that would be a red herring if we wanted Mma-like behavior, as > Ginac would handle the initial bit. > > My guess is that Maxima has good reasons for not doing this > automatically; you are welcome to email them with an example like > > > (%i2) display2d:false; > > (%o2) false > (%i3) cos(7/8*%pi); > > (%o3) cos(7*%pi/8) > > > and ask why it doesn't return what you expect, and I would hope they > have a pretty well-reasoned answer for this.
That's all fine and good in the abstract, but I really can't see any possible argument that this is anything but bad: sage: z = cos((1/7)*pi) + cos((6/7)*pi) sage: z.numerical_approx(200) 6.2230152778611417071440640537801242405902521687211671331011e-61 sage: bool(z == 0) False That's bad, because z is zero after all. Yes, "bool(foo==bar)" being True means that Sage couldn't prove that foo == bar, but in this case, since z does equal z, and it isn't difficult to change Sage that it would know this, I don't see why we don't do it. -- William -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
