about floating number
Travis Nixon
tnixon at avalanchesoftware.com
Thu Oct 19 12:29:36 EDT 2000
That's because it's not possible to exactly represent 2.8 in binary floating
point.
In fact, I'm sort of impressed that you only lost .0000000000000002 in
precision. When I try to represent 2.8 as a double in MS Devstudio, it
gives me 2.7999999523163, which is about 8 orders of magnitude less precise
than yours. :)
If you're worried about this loss of precision, do keep in mind that you're
talking about a loss of less than one quadrillionth(?) of a unit. :)
Basically, though, it's just a fact of life regarding floating point
numbers. Not all numbers are exactly representable in a base 2 binary
format.
----- Original Message -----
From: "Graduate" <g8741082 at ccunix.ccu.edu.tw>
Newsgroups: comp.lang.python
To: <python-list at python.org>
Sent: Thursday, October 19, 2000 1:28 AM
Subject: about floating number
> when I in python 2.0, I try to use floating number,
> but I have a proplem like this...
> >>> a = 2.8
> >>> a
> 2.7999999999999998
>
> why? or I forget some step??
> I try this in Linux & windows...
> thanks...
> --
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