function bcfact($fact, $scale = 100)
{
if ($fact == 1) {
return 1;
}
return bcmul($fact, bcfact(bcsub($fact, '1'), $scale), $scale);
}
/**
* Computes e^this, where e is Euler's constant.
* @param <int> $iters
* @param <int> $scale
* @return blaze\math\BigDecimal
*/
public function exponentialteWithE($iters = 7, $scale = 100)
{
/* Compute e^x. */
$res = bcadd('1.0', $this->value, $scale);
for ($i = 0; $i < $iters; $i++) {
$res += bcdiv(bcpow($this->value, bcadd($i, '2'), $scale), bcfact(bcadd($i, '2'), $scale), $scale);
}
return new BigDecimal($res);
}
