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 — 모든 bc 수학 함수의 기본 scale 인수값 설정
설명
bool bcscale
( int $scale
)
scale 인수를 명시하지 않는 모든 bc 수학 함수의 기본 scale 인수값을 설정합니다.
인수
- scale
-
소수점 아래 자리수
반환값
성공할 경우 TRUE를, 실패할 경우 FALSE를 반환합니다.
예제
Example #1 bcscale() 예제
<?php
// 기본 자리수 : 3
bcscale(3);
echo bcdiv('105', '6.55957'); // 16.007
// bcscale() 없이 동일한 결과
echo bcdiv('105', '6.55957', 3); // 16.007
?>
add a note
User Contributed Notesbcscale
Nitrogen
25-Jan-2009 05:00
25-Jan-2009 05:00
mwgamera at gmail dot com
06-Dec-2007 02:45
06-Dec-2007 02:45
These functions DO NOT round off your values. No arbitrary precision libraries do it this way. It stops calculating after reaching scale of decimal places, which mean that your value is cut off after scale number of digits, not rounded. To do the rounding use something like this:
<?php
function bcround($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 11:50
08-Feb-2006 11:50
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
?>