[Python-bugs-list] [Bug #127072] log, exp & sqrt (math) function innaccuracies

[noreply@sourceforge.net]

Bug #127072, was updated on 2000-Dec-29 05:50
Here is a current snapshot of the bug.

Project: Python
Category: Extension Modules
Status: Open
Resolution: None
Bug Group: None
Priority: 5
Submitted by: salmoni
Assigned to : tim_one
Summary: log, exp & sqrt (math) function innaccuracies

Details: Perform:

y = int(math.exp(math.log(math.sqrt(2) * math.sqrt(2))))

nb,

exp(log(x)) = x
sqrt(x) * sqrt(x) = x

This produces 0 when the answer should be 1 - the floating point number is
0.99999999999999956 but it should be 1.0

This was reproduced on Windows (95) and Linux (RedHat 6.0) both using
Python 2.0.

Alan James Salmoni


Follow-Ups:

Date: 2000-Dec-30 18:16
By: fdrake

Comment:
Tim's the math guy, so this is his.
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For detailed info, follow this link:
http://sourceforge.net/bugs/?func=detailbug&bug_id=127072&group_id=5470