private function round($n, $sigfigs)
{
$new_log = (int) floor(log(abs($n), 10));
// Number of digits left of decimal - 1
$rp = $sigfigs - $new_log - 1;
// Number of decimal places needed
$neg = $n < 0 ? '-' : '';
// Negative sign
if ($this->bcmath) {
if ($rp >= 0) {
$n = bcadd($n, $neg . '0.' . str_repeat('0', $rp) . '5', $rp + 1);
$n = bcdiv($n, '1', $rp);
} else {
// This algorithm partially depends on the standardized
// form of numbers that comes out of bcmath.
$n = bcadd($n, $neg . '5' . str_repeat('0', $new_log - $sigfigs), 0);
$n = substr($n, 0, $sigfigs + strlen($neg)) . str_repeat('0', $new_log - $sigfigs + 1);
}
return $n;
} else {
return $this->scale(round($n, $sigfigs - $new_log - 1), $rp + 1);
}
}