Steven D'Aprano wrote:
On Sun, 13 Sep 2009 17:58:14 -0500, Robert Kern wrote:
Exactly -- there are 2**53 distinct floats on most IEEE systems, the vast
majority of which might as well be "random". What's the point of caching
numbers like 2.5209481723210079? Chances are it will never come up again
in a calculation.
You are missing a few orders of magnitude here; there are approx. 2 ** 64
distinct floats. 2 ** 53 is the mantissa of regular floats. There are
2**52 floats X where 1.0 <= X < 2.0.
The number of "normal" floats is 2 ** 64 - 2 ** 52 + 1.
The number including denormals and -0.0 is 2 ** 64 - 2 ** 53.
There are approx. 2 ** 53 NaNs (half with the sign bit on).
--Scott David Daniels
scott.dani...@acm.org
--
http://mail.python.org/mailman/listinfo/python-list
