PHPOffice / PhpSpreadsheet

     * @param    life        Number of periods over which the asset is depreciated

     * @return    float

     */

    public static function SLN($cost, $salvage, $life)

    {

        $cost = Functions::flattenSingleValue($cost);

        $salvage = Functions::flattenSingleValue($salvage);

        $life = Functions::flattenSingleValue($life);

        // Calculate

        if ((is_numeric($cost)) && (is_numeric($salvage)) && (is_numeric($life))) {

            if ($life < 0) {

                return Functions::NAN();

            }

            return ($cost - $salvage) / $life;

        }

        return Functions::VALUE();

    }

     * @param    int        $numInSet    Number of objects in each permutation

     * @return    int        Number of permutations

     */

    public static function PERMUT($numObjs, $numInSet)

    {

        $numObjs = Functions::flattenSingleValue($numObjs);

        $numInSet = Functions::flattenSingleValue($numInSet);

        if ((is_numeric($numObjs)) && (is_numeric($numInSet))) {

            $numInSet = floor($numInSet);

            if ($numObjs < $numInSet) {

                return Functions::NAN();

            }

            return round(MathTrig::FACT($numObjs) / MathTrig::FACT($numObjs - $numInSet));

        }

        return Functions::VALUE();

    }

     * @param    float    $stdDev        Standard Deviation

     * @return    float    Standardized value

     */

    public static function STANDARDIZE($value, $mean, $stdDev)

    {

        $value = Functions::flattenSingleValue($value);

        $mean = Functions::flattenSingleValue($mean);

        $stdDev = Functions::flattenSingleValue($stdDev);

        if ((is_numeric($value)) && (is_numeric($mean)) && (is_numeric($stdDev))) {

            if ($stdDev <= 0) {

                return Functions::NAN();

            }

            return ($value - $mean) / $stdDev;

        }

        return Functions::VALUE();

    }