lib/Math/Statistics.php
public static function stdev(array $values, $sample = false)
    {
        $variance = self::variance($values, $sample);

        return \sqrt($variance);
    }
public static function stdev(array $values, $sample = false)
    {
        $variance = self::variance($values, $sample);

        return \sqrt($variance);
    }
public static function stdev ( array $ values , $ sample = false ) { $ variance = self :: variance ( $ values , $ sample ) ; return \ sqrt ( $ variance ) ; }
Return the standard deviation of a given population.

@param array $values
@param bool $sample

@return float
Return the standard deviation of a given population .