Litipk\BigNumbers\DecimalConstants::one PHP Méthode

    public static function one()
    {
        if (self::$ONE === null) {
            self::$ONE = Decimal::fromInteger(1);
        }
        return self::$ONE;
    }

 /**
  * Internal method used to compute arctan and arccotan
  *
  * @param Decimal $x
  * @param Decimal $firstTerm
  * @param $scale
  * @return Decimal
  */
 private static function simplePowerSerie(Decimal $x, Decimal $firstTerm, $scale)
 {
     $approx = $firstTerm;
     $change = InfiniteDecimal::getPositiveInfinite();
     $xPowerN = DecimalConstants::One();
     // Calculates x^n
     $sign = DecimalConstants::One();
     // Calculates a_n
     for ($i = 1; !$change->floor($scale + 2)->isZero(); $i++) {
         $xPowerN = $xPowerN->mul($x);
         if ($i % 2 === 0) {
             $factorN = DecimalConstants::zero();
         } else {
             if ($i % 4 === 1) {
                 $factorN = DecimalConstants::one()->div(Decimal::fromInteger($i), $scale + 2);
             } else {
                 $factorN = DecimalConstants::negativeOne()->div(Decimal::fromInteger($i), $scale + 2);
             }
         }
         if (!$factorN->isZero()) {
             $change = $factorN->mul($xPowerN, $scale + 2);
             $approx = $approx->add($change, $scale + 2);
         }
     }
     return $approx->round($scale);
 }