BUG: A wrong result of computation in python2.6
version: Python 2.6 OS : Windows 7 The variable x below should have been 10(integer) after the expression evaluates. It ,however, gets the value 10.000000000000002 (float) , as follows, --------------------------------------------
x=math.exp ( math.log(10.0)) x 10.000000000000002
x=math.exp ( math.log(10)) x 10.000000000000002
In mathematics, the result is not right.
Hi Matthew, thanks for your email. On Wed, Feb 16, 2011 at 05:47, matthew chao <mathewchao@gmail.com> wrote:
version: Python 2.6 OS : Windows 7
The variable x below should have been 10(integer) after the expression evaluates. It ,however, gets the value 10.000000000000002 (float) , as follows, --------------------------------------------
x=math.exp ( math.log(10.0)) x 10.000000000000002
x=math.exp ( math.log(10)) x 10.000000000000002
In mathematics, the result is not right.
I could try to explain why this is "expected" on a computer, but I could never do it even near as good as David Goldberg in his famous paper "what every scientist should know about floating-point arithmetic"[1] [1] http://cr.yp.to/2005-590/goldberg.pdf Cheers, -- Sandro Tosi (aka morph, morpheus, matrixhasu) My website: http://matrixhasu.altervista.org/ Me at Debian: http://wiki.debian.org/SandroTosi
participants (2)
-
matthew chao -
Sandro Tosi