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? :) - 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
