bcmul
<?php
bcscale(100);
/*
* Computes the natural logarithm using a series.
* @author Thomas Oldbury.
* @license Public domain.
*/
function bcln($a, $iter = 10)
{
$result = "0.0";
for($i = 0; $i < $iter; $i++)
{
$pow = (1 + (2 * $i));
$mul = bcdiv("1.0", $pow);
$fraction = bcmul($mul, bcpow(bcsub($a, "1.0") / bcadd($a, "1.0"), $pow));
$result = bcadd($fraction, $result);
}
return bcmul("2.0", $result);
}
/*
* Computes the base2 log using baseN log.
* @note Requires above functions.
* @author Thomas Oldbury.
* @license Public domain.
*/
function bclog2($a, $iter = 10)
{
return bcdiv(bcln($a, $iter), bcln("2", $iter));
}
/*
* Computes the base10 log using baseN log.
* @note Requires above functions.
* @author Thomas Oldbury.
* @license Public domain.
*/
function bclog10($a, $iter = 10)
{
return bcdiv(bcln($a, $iter), bcln("10", $iter));
}
?>
bcpow
(PHP 4, PHP 5)
bcpow — عددی با دقت دلخواه به توان عدد دیگر
Description
string bcpow
( string $left_operand
, string $right_operand
[, int $scale
] )
left_operand به توان right_operand.
Parameters
- left_operand
-
عملوند چپ به عنوان رشته.
- right_operand
-
عملوند راست به عنوان رشته.
- scale
-
This optional parameter is used to set the number of digits after the decimal place in the result. You can also set the global default scale for all functions by using bcscale().
Return Values
بازگرداندن نتیجه به عنوان رشته.
Examples
Example #1 مثال bcpow()
<?php
echo bcpow('4.2', '3', 2); // 74.08
?>
See Also
- bcpowmod() - Raise an arbitrary precision number to another, reduced by a specified modulus
- bcsqrt() - دریافت ریشه عدد با دقت دلخواه
add a note
User Contributed Notes
bcpow - [3 notes]
thomas at tgohome dot com ¶
3 years ago
Michael Bailey (jinxidoru at byu dot net) ¶
8 years ago
bcpow() only supports exponents less than or equal to 2^31-1. Also, bcpow() does not support decimal numbers. If you have scale set to 0, then the exponent is converted to an interger; otherwise an error is generated.
--
Michael Bailey
http://www.jinxidoru.com