On Mar 21, 11:25 pm, Dima Pasechnik <dimp...@gmail.com> wrote: > On Wednesday, 21 March 2012 22:39:25 UTC-4, kcrisman wrote: > > > On Mar 21, 10:00 pm, Gonzalo Tornaria <torna...@math.utexas.edu> > > wrote: > > > In sage 4.8: > > > > sage: NaN - NaN > > > sage: 0 > > > sage: NaN + NaN > > > 2*NaN > > > sage: NaN * NaN > > > NaN^2 > > > Naturally! Since NaN is a symbolic expression, apparently: > > > sage: type(NaN) > > <type 'sage.symbolic.expression.Expression'> > > > See sage/symbolic/constants.py, e.g. > > >http://hg.sagemath.org/sage-main/file/c239be1054e0/sage/symbolic/cons... > > Based on the code in that file, I think that means this is the Pynac > > NaN. > > > You can't do this in vanilla IPython. > > > In [1]: NaN > > NameError: name 'NaN' is not defined > > In [7]: float('nan') > > Out[7]: nan > > > Also, it looks like we have two different NaN/nan's hanging around. > > > sage: float('nan') > > nan > > sage: float('NaN') > > nan > > sage: SR(float('nan')) > > nan > > sage: bool(SR(float('nan')) == NaN) > > False > > > Naturally, none of this solves your problem, but maybe it puts it in > > context... why not have polynomials in NaN, after all? :) > > Non-standard analysis framework, brought to you by a colony of Sage bugs...
So you're saying this resolves part of http://trac.sagemath.org/sage_trac/ticket/10015 ? ;-) -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
