code: public static function IMABS($complexNumber)
      {
          $complexNumber = Functions::flattenSingleValue($complexNumber);
  
          $parsedComplex = self::parseComplex($complexNumber);
  
          return sqrt(
              ($parsedComplex['real'] * $parsedComplex['real']) +
              ($parsedComplex['imaginary'] * $parsedComplex['imaginary'])
          );
      }
docs: IMABS.
  
  Returns the absolute value (modulus) of a complex number in x + yi or x + yj text format.
  
  Excel Function:
  IMABS(complexNumber)
  
  @param string $complexNumber the complex number for which you want the absolute value
  
  @return float