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/constants.py#l665 > > 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... > - kcrisman -- 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
