Division [maybe a bug]

Hello!

$var1= 2155243640%31104000;
$var2= 2147309244%31104000;

echo $var1 // Return -24651656
echo $var2 // Return 1133244

$var2 return the correct result, but $var1 is wrong (the correct
result is 9067640)

¿?

Thanks for the help

jo opp wrote:
> Hello!
>
> $var1= 2155243640%31104000;
> $var2= 2147309244%31104000;
>
> echo $var1 // Return -24651656
> echo $var2 // Return 1133244
>
> $var2 return the correct result, but $var1 is wrong (the correct
> result is 9067640)

Probably because the maximum signed 32 bit integer value is
2,147,483,648

if you are dealing with numbers that large, consider using some
arbitrary precision math functions that can work with as large of
numbers as you need.


http://us3.php.net/manual/en/refs.mathcrypto.math.php



--
Chris W
KE5GIX

"Protect your digital freedom and privacy, eliminate DRM,
learn more at http://www.defectivebydesign.org/what_is_drm"

Ham Radio Repeater Database.
http://hrrdb.com

2008/5/11 Chris W <2wsxdr5@cox.net>:
> jo opp wrote:
>
> > Hello!
> >
> > $var1= 2155243640%31104000;
> > $var2= 2147309244%31104000;
> >
> > echo $var1 // Return -24651656
> > echo $var2 // Return 1133244
> >
> > $var2 return the correct result, but $var1 is wrong (the correct
> > result is 9067640)
> >
>
> Probably because the maximum signed 32 bit integer value is
> 2,147,483,648
>

OK, but with bigger numbers works fine again.
Right now I made a function to deal with this issue:

function remainder($dividend,$divisor){
$remainder= $dividend-(floor($dividend/$divisor)*$divisor);
return $remainder;
}

What do you think about it?

> if you are dealing with numbers that large, consider using some arbitrary
> precision math functions that can work with as large of numbers as you need.
>
>
> http://us3.php.net/manual/en/refs.mathcrypto.math.php
>
>
>
> --
> Chris W
> KE5GIX
>
> "Protect your digital freedom and privacy, eliminate DRM,
> learn more at http://www.defectivebydesign.org/what_is_drm"
>
> Ham Radio Repeater Database.
> http://hrrdb.com
>

jo opp wrote:
> 2008/5/11 Chris W <2wsxdr5@cox.net>:
>> jo opp wrote:
>>
>>> Hello!
>>>
>>> $var1= 2155243640%31104000;
>>> $var2= 2147309244%31104000;
>>>
>>> echo $var1 // Return -24651656
>>> echo $var2 // Return 1133244
>>>
>>> $var2 return the correct result, but $var1 is wrong (the correct
>>> result is 9067640)
>>>
>> Probably because the maximum signed 32 bit integer value is
>> 2,147,483,648
>>
>
> OK, but with bigger numbers works fine again.
> Right now I made a function to deal with this issue:
>
> function remainder($dividend,$divisor){
> $remainder= $dividend-(floor($dividend/$divisor)*$divisor);
> return $remainder;
> }
>
> What do you think about it?
>

That will convert the numbers to floating point, which will give you
round off error if the numbers get too big.

--
Chris W
KE5GIX

"Protect your digital freedom and privacy, eliminate DRM,
learn more at http://www.defectivebydesign.org/what_is_drm"

Ham Radio Repeater Database.
http://hrrdb.com