/** * Returns the arc tangent of a number. * * @param float $number * @param float $y optional * @return float The arc tangent of a number in radians. */ public function atan($number) { if (func_num_args() == 2) { // If the user has passed in two parameters, let's // assume that they want to calculate Atan2. return $this->executionEngine->atan2(func_get_arg(1), func_get_arg(2)); } // If the number of arguments is not two, just calculate // the atan as normal. return (double) $this->executionEngine->atan($number); }