ID: 41907
Updated by: [EMAIL PROTECTED]
Reported By: milman at gmx dot de
Status: Bogus
Bug Type: *Math Functions
Operating System: windows xp
PHP Version: 5.2.3
New Comment:
php -r 'echo sprintf("%15.20f", 8.155);'
8.15499999999999936051
Previous Comments:
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[2007-07-05 18:48:25] milman at gmx dot de
sorry but i can't accept this answer.
for me it seem like, round-problem than bogus and standard answer.
php use common round (Symmetric Arithmetic Rounding)
Decide which is the last digit to keep.
Increase it by 1 if the next digit is 5 or more (this is called
rounding up)
Leave it the same if the next digit is 4 or less (this is called
rounding down)
and then round (8.155, 2) is 8.16 and not 8.15
sprintf ("%15.8f", 8.155) is 000008.15500000
so it is not a problem from intern representation.
the rounding problem occurs at number_format and sprintf too.
round
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[2007-07-05 16:30:05] [EMAIL PROTECTED]
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.
If you would like to know more about "floats" and what IEEE
754 is read this:
http://docs.sun.com/source/806-3568/ncg_goldberg.html
Thank you for your interest in PHP.
.
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[2007-07-05 16:27:24] milman at gmx dot de
Description:
------------
wrong result from round(64.365,2)
should be 64.37 not 64.36
Reproduce code:
---------------
<?
echo "right: round (63.365,2) = " . round (63.365,2) . "<br>\n" ;
echo "wrong: round (64.365,2) = " . round (64.365,2) . "<br>\n" ;
echo "wrong: round (81.365,2) = " . round (81.365,2) . "<br>\n" ;
echo "right: round (82.365,2) = " . round (82.365,2) . "<br>\n" ;
?>
Expected result:
----------------
allway .37 not somtimes .36
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Edit this bug report at http://bugs.php.net/?id=41907&edit=1
