#13559: fast_float yields infinity when Python does, but should handle bigger
numbers
------------------------------+---------------------------------------------
Reporter: nthiery | Owner: jason, was
Type: defect | Status: new
Priority: major | Milestone: sage-5.5
Component: graphics | Resolution:
Keywords: agregation | Work issues:
Report Upstream: N/A | Reviewers:
Authors: | Merged in:
Dependencies: | Stopgaps:
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Comment (by kcrisman):
> In fact, I just realized why you are getting the errors. The problem is
with `fast_float`.
> {{{
> sage: from sage.ext.fast_eval import fast_float
> sage: f(x) = exp(x)
> sage: v = f.variables()
> sage: F = fast_float(f, *v)
> sage: F(100000.0)
> inf
> }}}
Huh, that is not good.
{{{
sage: F(709.7)
1.6549840276802644e+308
sage: F(709.8)
inf
}}}
That's as much bisecting as I want to do. And really, here is what is
going on, I suspect.
{{{
In [3]: import math
In [6]: math.exp(709.8)
---------------------------------------------------------------------------
OverflowError Traceback (most recent call
last)
/Users/.../<ipython console> in <module>()
OverflowError: math range error
In [7]: math.exp(709.7)
Out[7]: 1.6549840276802644e+308
}}}
So `fast_float` really is doing floats, but we need something better than
that.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/13559#comment:8>
Sage <http://www.sagemath.org>
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