Executing bcsacle() will change the scale value of fpm.conf, not only the current process.
bcscale
(PHP 4, PHP 5, PHP 7)
bcscale — Setzt die Genauigkeit aller BCmath-Funktionen
Beschreibung
int bcscale
([ int
$scale
] )
Diese Funktionen legt die Standard-Genauigkeit aller im Folgenden
aufgerufenden BCmath-Funktionen fest, die nicht explizit die
Genauigkeit angeben.
Wird scale ausgelassen, ermittelt die Funktion die
aktuelle Genauigkeit.
Parameter-Liste
-
scale -
Die Genauigkeitsangabe.
Rückgabewerte
Gibt die alte Genauigkeit zurück.
Changelog
| Version | Beschreibung |
|---|---|
| 7.3.0 |
bcscale() kann nun verwendet werden, um die aktuelle
Genauigkeit zu ermitteln; wird es als Setter verwendet, gibt es nun die
vorherige Genauigkeit zurück. Zuvor war scale
obligatorisch, und bscale() gab immer TRUE zurück.
|
Beispiele
Beispiel #1 bcscale()-Beispiel
<?php
// Standard-Genauigkeit: 3
bcscale(3);
echo bcdiv('105', '6.55957'); // 16.007
// Die selbe Operation ohne Verwendung von bcscale()
echo bcdiv('105', '6.55957', 3); // 16.007
?>
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User Contributed Notes 7 notes
sicerwork at aliyun dot com ¶
1 year ago
mwgamera at gmail dot com ¶
10 years ago
These functions DO NOT round off your values. No arbitrary precision libraries do it this way. It stops calculating after reaching scale of decimal places, which mean that your value is cut off after scale number of digits, not rounded. To do the rounding use something like this:
<?php
function bcround($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", $scale);
}
?>
herslyadam at gmail dot com ¶
4 years ago
edited bcround function with negative number support:
<?php
function bcround($number, $scale=0) {
if($scale < 0) $scale = 0;
$sign = '';
if(bccomp('0', $number, 64) == 1) $sign = '-';
$increment = $sign . '0.' . str_repeat('0', $scale) . '5';
$number = bcadd($number, $increment, $scale+1);
return bcadd($number, '0', $scale);
}
?>
ravenswd at gmail dot com ¶
5 years ago
Simple, easy way to remove excess trailing zeros using rtrim:
<php>
// $total is the result of a bcmath calculation
if ( strpos($total, '.') !== false ):
$total = rtrim($total, '0');
$total = rtrim($total, '.');
endif;
</php>
invincible at limitedintelligence dot com ¶
12 years ago
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 $abc; // 22.83152970
?>
rastislav dot bostik at bwd21 dot cz ¶
6 years ago
Previously stated one liner trailing 0 removing using rtrim() works fine except following class of subcases:
<?php
echo rtrim('100.0000', '0.'); // 1 instead 100
echo rtrim('1230.00000000', '0.'); // 123 instead 1230
?>
What seems to be working to me is using regular expression replacement. Althought it`s probably not that fast as rtrim(), I hope it should be more reliable:
<?php
function removeFloatNumStringZeroTrailer($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
?>
nemesarial at gmail dot com ¶
2 years ago
To remove trailing zeros when using large bcscale number can be done by casting to float when ready to display the number.
<?php
bcscale(15);
$a=123.456;
$b=0.123;
$_ab=bcadd($a,$b);
echo $_ab;
// 123.579000000000000
$ab = (float)$_ab;
echo $ab;
// 123.579
?>
