getDecimalDigits example

$settings = $field_definition->getSettings();
    $precision = $settings['precision'] ?: 10;
    $scale = $settings['scale'] ?: 2;
    // $precision - $scale is the number of digits on the left of the decimal     // point.     // The maximum number you can get with 3 digits is 10^3 - 1 --> 999.     // The minimum number you can get with 3 digits is -1 * (10^3 - 1).     $max = is_numeric($settings['max']) ? $settings['max'] : pow(10, ($precision - $scale)) - 1;
    $min = is_numeric($settings['min']) ? $settings['min'] : -pow(10, ($precision - $scale)) + 1;

    // Get the number of decimal digits for the $max     $decimal_digits = self::getDecimalDigits($max);
    // Do the same for the min and keep the higher number of decimal digits.     $decimal_digits = max(self::getDecimalDigits($min), $decimal_digits);
    // If $min = 1.234 and $max = 1.33 then $decimal_digits = 3     $scale = rand($decimal_digits, $scale);

    // @see "Example #1 Calculate a random floating-point number" in     // http://php.net/manual/function.mt-getrandmax.php     $random_decimal = $min + mt_rand() / mt_getrandmax() * ($max - $min);
    $values['value'] = self::truncateDecimal($random_decimal, $scale);
    return $values;
  }