ID: 26526
Updated by: [EMAIL PROTECTED]
Reported By: vince at blue-box dot net
-Status: Open
+Status: Bogus
Bug Type: Math related
Operating System: FreeBSD 4.8-RELEASE-p13
PHP Version: 4CVS-2003-12-04 (stable)
New Comment:
Floating point values have a limited precision. Hence a value might
not have the same string representation after any processing. That also
includes writing a floating point value in your script and directly
printing it without any mathematical operations.
Thank you for your interest in PHP.
# cat t.php
<?php
ini_set('precision', 20);
$value = 6*.029*1000;
echo "value = $value\n";
?>
# php t.php
value = 174.00000000000002842
Previous Comments:
------------------------------------------------------------------------
[2003-12-04 15:16:57] vince at blue-box dot net
Description:
------------
When using certain integers derived from multiplying integers and
floating point numbers with ceil(), ceil() will increment the number
even though it shouldn't be.
Reproduce code:
---------------
<?php
$value = 6*.029*1000;
echo "value = $value\n";
$value = ceil($value);
echo "value = $value\n";
?>
Expected result:
----------------
Since 6*.029*1000 comes out to be exactly 174, I would expect the
output of the above script to be:
value = 174
value = 174
Actual result:
--------------
value = 174
value = 175
It seems like if this were a floating point precision problem the first
echo statement in the code example would produce something like:
value = 174.000000000000000000001
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=26526&edit=1
