code: public static function IMLOG2($complexNumber)
      {
          $complexNumber = Functions::flattenSingleValue($complexNumber);
  
          $parsedComplex = self::parseComplex($complexNumber);
  
          if (($parsedComplex['real'] == 0.0) && ($parsedComplex['imaginary'] == 0.0)) {
              return Functions::NAN();
          } elseif (($parsedComplex['real'] > 0.0) && ($parsedComplex['imaginary'] == 0.0)) {
              return log($parsedComplex['real'], 2);
          }
  
          return self::IMPRODUCT(log(self::EULER, 2), self::IMLN($complexNumber));
      }
docs: IMLOG2.
  
  Returns the base-2 logarithm of a complex number in x + yi or x + yj text format.
  
  Excel Function:
  IMLOG2(complexNumber)
  
  @param string $complexNumber the complex number for which you want the base-2 logarithm
  
  @return string