| philip@php.net 2007-04-18, 6:59 pm |
| ID: 41108
Updated by: philip@php.net
-Summary: pow() doesn't handle negative exponents
Reported By: jack dot nerad at comcast dot net
-Status: Open
+Status: Verified
Bug Type: Documentation problem
-PHP Version: 6CVS-2007-04-17 (CVS)
+PHP Version: Irrelevant
New Comment:
Thank you guys for the bug report and patch, it's the right idea but
the php manual has change logs for functions.
Tasks for tackling this bug report:
- Find out exactly which PHP version(s) this behavior changed
- Add an entry to the changelog role in math/functions/pow.xml
- Add an example to these docs using a negative exponent, and
if appropriate add version info within the example comments
- Decide if other functions were affected by this change in the
php sources (See also: NEWS, php-src/)
- If a 'fairly recent' change, add a nice example that works
in all versions
- Clean user notes
A good starting place:
- http://cvs.php.net/viewvc.cgi/php-s...math.c?view=log
- http://php.net/manual/en/function.pow
Previous Comments:
------------------------------------------------------------------------
[2007-04-18 20:23:24] ljbuesch at purdue dot edu
### Eclipse Workspace Patch 1.0
#P PHPDoc
Index: en/reference/math/functions/pow.xml
========================================
===========================
RCS file: /repository/phpdoc/en/reference/math/functions/pow.xml,v
retrieving revision 1.11
diff -u -r1.11 pow.xml
--- en/reference/math/functions/pow.xml 31 Mar 2007 19:18:23
-0000 1.11
+++ en/reference/math/functions/pow.xml 18 Apr 2007 20:18:37 -0000
@@ -16,11 +16,6 @@
Returns <parameter>base</parameter> raised to the power of
<parameter>exp</parameter>.
</para>
- <note>
- <para>
- PHP cannot handle negative <parameter>exp</parameter>s.
- </para>
- </note>
<warning>
<para>
In PHP 4.0.6 and earlier <function>pow</function> always returned
------------------------------------------------------------------------
[2007-04-18 06:09:11] derick@php.net
Made it a doc problem, which it is. It might be that in the past this
negative exponent did not work though.
------------------------------------------------------------------------
[2007-04-18 00:36:25] jack dot nerad at comcast dot net
Now that's turnaround time! I didn't even have to upgrade to the
latest version! :)
Actually, I was looking for how to do exponentiation in the docs, found
pow(), and read:
"Note: PHP cannot handle negative exps."
at
http://us.php.net/manual/en/function.pow.php
There's pretty much only one way to read that, I think, so I didn't
bother to look for features explicitly ruled out by the docs. In
addition, there are a bunch of notes with hacks on how to get around the
no negative exponents 'feature?'
(shrug)
Close this feature request, or whatever. Maybe change it to a bug in
the docs?
------------------------------------------------------------------------
[2007-04-17 08:27:42] tony2001@php.net
What are you talking about?
# php -r 'var_dump(pow(2,-2));'
float(0.25)
------------------------------------------------------------------------
[2007-04-17 01:37:39] jack dot nerad at comcast dot net
Description:
------------
It is a sin that PHP cannot handle negative exponents. Every other
respectable language that has half the vocabulary that PHP has can
handle negative exponents. Heck, even the windows calculator can handle
negative exponents. Please. Mature and refine the language to include
this ability.
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=41108&edit=1
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