bcpowmod
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.
bcscale
(PHP 4, PHP 5)
bcscale — Set default scale parameter for all bc math functions
Description
bool bcscale
( int $scale
)
Sets the default scale parameter for all subsequent bc math functions that do not explicitly specify a scale parameter.
Parameters
- scale
-
The scale factor.
Return Values
Returns TRUE on success or FALSE on failure.
Examples
Example #1 bcscale() example
<?php
// default scale : 3
bcscale(3);
echo bcdiv('105', '6.55957'); // 16.007
// this is the same without bcscale()
echo bcdiv('105', '6.55957', 3); // 16.007
?>
add a note
User Contributed Notesbcscale
Nitrogen
25-Jan-2009 03:00
25-Jan-2009 03:00
mwgamera at gmail dot com
06-Dec-2007 12:45
06-Dec-2007 12:45
These functions DO NOT round off your values. No arbitrary precision libraries do it this way. It stops calculating after reaching scale of decimal places, which mean that your value is cut off after scale number of digits, not rounded. To do the rounding use something like this:
<?php
function bcround($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 09:50
08-Feb-2006 09:50
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
?>