(PHP 4, PHP 5, PHP 7, PHP 8)
log — Natural logarithm
If the optional base parameter is specified,
log() returns logbasenum, otherwise log()
returns the natural logarithm of num.
numThe value to calculate the logarithm for
baseThe optional logarithmic base to use (defaults to 'e' and so to the natural logarithm).
The logarithm of num to
base, if given, or the
natural logarithm.
more general version, works fine on negative, very big ($value > 1E+18) and very small ($value < 1E-18) numbers.
function expn($value, $prec = 3, $base = 1000, $prefix = '') {
$e = array('a', 'f', 'p', 'n', 'u', 'm', '', 'k', 'M', 'G', 'T', 'P', 'E');
$p = min(max(floor(log(abs($value), $base)), -6), 6);
return round((float)$value / pow($base, $p), $prec) . $prefx . $e[$p + 6];
}For those interested. Works with older than 4.3 versions.
<?php
function byteConvert($bytes)
{
$s = array('B', 'Kb', 'MB', 'GB', 'TB', 'PB');
$e = floor(log($bytes)/log(1024));
return sprintf('%.2f '.$s[$e], ($bytes/pow(1024, floor($e))));
}
?>