From: boydell at orbsix dot com
Operating system: WinXP, Linux
PHP version: 5.2.3
PHP Bug Type: Math related
Bug description: double precision error
Description:
------------
The math on the following should be zero.
echo (65 + 50 - 50 + 15 - 15 + 100 - 100 + 50 + 16.50 - 36.50 + 88.21 -
38.21 - 145);
but we get: -2.84217094304E-14
Reproduce code:
---------------
$list = array(65, 50, -50, 15, -15, 100, -100, 50, 16.50, -36.50, 88.21,
-38.21, -145);
$current = 0;
foreach($list as $number) {
echo $current . "+" . $number . "=";
$current += $number;
echo $current . "\n<br>";
}
Expected result:
----------------
0+65=65
65+50=115
115+-50=65
65+15=80
80+-15=65
65+100=165
165+-100=65
65+50=115
115+16.5=131.5
131.5+-36.5=95
95+88.21=183.21
183.21+-38.21=145
145+-145=0
Actual result:
--------------
0+65=65
65+50=115
115+-50=65
65+15=80
80+-15=65
65+100=165
165+-100=65
65+50=115
115+16.5=131.5
131.5+-36.5=95
95+88.21=183.21
183.21+-38.21=145
145+-145=-2.8421709430404E-14
--
Edit bug report at http://bugs.php.net/?id=42333&edit=1
--
Try a CVS snapshot (PHP 4.4):
http://bugs.php.net/fix.php?id=42333&r=trysnapshot44
Try a CVS snapshot (PHP 5.2):
http://bugs.php.net/fix.php?id=42333&r=trysnapshot52
Try a CVS snapshot (PHP 6.0):
http://bugs.php.net/fix.php?id=42333&r=trysnapshot60
Fixed in CVS: http://bugs.php.net/fix.php?id=42333&r=fixedcvs
Fixed in release:
http://bugs.php.net/fix.php?id=42333&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=42333&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=42333&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=42333&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=42333&r=support
Expected behavior: http://bugs.php.net/fix.php?id=42333&r=notwrong
Not enough info:
http://bugs.php.net/fix.php?id=42333&r=notenoughinfo
Submitted twice:
http://bugs.php.net/fix.php?id=42333&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=42333&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=42333&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=42333&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=42333&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=42333&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=42333&r=float
No Zend Extensions: http://bugs.php.net/fix.php?id=42333&r=nozend
MySQL Configuration Error: http://bugs.php.net/fix.php?id=42333&r=mysqlcfg
