bcpowmod
Previously stated one liner trailing 0 removing using rtrim() works fine except following class of subcases:
<?php
echo rtrim('100.0000', '0.'); // 1 instead 100
echo rtrim('1230.00000000', '0.'); // 123 instead 1230
?>
What seems to be working to me is using regular expression replacement. Althought it`s probably not that fast as rtrim(), I hope it should be more reliable:
<?php
function removeFloatNumStringZeroTrailer($input) {
$patterns = array('/[\.][0]+$/','/([\.][0-9]*[1-9])([0]*)$/');
$replaces = array('','$1');
return preg_replace($patterns,$replaces,$input);
}
echo removeFloatNumStringZeroTrailer('100.0000'); // says 100
echo removeFloatNumStringZeroTrailer('1230.00000000'); // says 1230
?>
bcscale
(PHP 4, PHP 5)
bcscale — Spécifie le nombre de décimales par défaut pour toutes les fonctions
Description
bool bcscale
( int $scale
)
Spécifie la précision par défaut pour toutes les fonctions mathématiques sur des nombres de taille arbitraire qui suivent et qui omettent le paramètre scale.
Liste de paramètres
- scale
-
Le facteur de précision.
Valeurs de retour
Cette fonction retourne TRUE en cas de succès ou FALSE si une erreur survient.
Exemples
Exemple #1 Exemple avec bcscale()
<?php
// précision par défaut : 3
bcscale(3);
echo bcdiv('105', '6.55957'); // 16.007
// la même chose sans utiliser bcscale()
echo bcdiv('105', '6.55957', 3); // 16.007
?>
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User Contributed Notes
bcscale
rastislav dot bostik at bwd21 dot cz
25-Jan-2012 02:20
dcz at phpbb-seo dot com
25-Mar-2011 07:05
The general approach for a one liner trailing 0 removing would be :
<?php
echo rtrim('1.2500000000', '0.'); // 1.25
echo rtrim('1.00000000', '0.'); // 1
?>
Which seems totally appropriate since we are working with strings, and also is likely to be the fastest way.
Nitrogen
25-Jan-2009 09:00
Good day,
I made a little function to remove the excess zeroes after calculations.. it makes them cleaner and more presentable.
<?php
function DecimalClean($Input) {
$Input=explode('.',$Input,2);
if(!isset($Input[1])) $Input[1]=0;
for($i=(strlen($Input[1])-1);$i>0;$i--) {
if($Input[1]{$i}=='0')
$Input[1]=substr($Input[1],0,-1);
else break;
}
return(sprintf('%s%s',$Input[0],($Input[1]!='0')?".{$Input[1]}":''));
}
BCScale(10); // allow 10 decimals
$Sum = BCDiv(10,8); // make a calculation
printf("Result #1: %s\n", $Sum);
// 1.2500000000
printf("Result #2: %s\n", DecimalClean($Sum));
// 1.25
?>
Hope this helps,
Nitrogen.
mwgamera at gmail dot com
05-Dec-2007 06:45
These functions DO NOT round off your values. No arbitrary precision libraries do it this way. It stops calculating after reaching scale of decimal places, which mean that your value is cut off after scale number of digits, not rounded. To do the rounding use something like this:
<?php
function bcround($number, $scale=0) {
$fix = "5";
for ($i=0;$i<$scale;$i++) $fix="0$fix";
$number = bcadd($number, "0.$fix", $scale+1);
return bcdiv($number, "1.0", $scale);
}
?>
invincible at limitedintelligence dot com
08-Feb-2006 03:50
If you don't set the default scale, be careful when you're chaining together several BC math functions - since by default, these functions will round off your values, losing accuracy very quickly:
<?php
$a = 1.234
$b = 2.345
$c = 7.890
$ab = bcmul($a,$b); // 2
$abc = bcmul($ab,$c);
echo $abc; // 15
?>
... compare with the answer you get when you use more decimal places:
<?php
$a = 1.234
$b = 2.345
$c = 7.890
bcscale(15);
$ab = bcmul($a,$b); // 2.893730
$abc = bcmul($ab,$c);
echo $abc; // 22.83152970
?>