MathPHP\Statistics\Distribution::stemAndLeafPlot PHP Метод

    public static function stemAndLeafPlot(array $values, bool $print = false) : array
    {
        // Split each value into stem and leaf
        sort($values);
        $plot = array();
        foreach ($values as $value) {
            $stem = $value / 10;
            $leaf = $value % 10;
            if (!isset($plot[$stem])) {
                $plot[$stem] = array();
            }
            $plot[$stem][] = $leaf;
        }
        // Fill in any empty keys in the distribution we had no stem/leaves for
        $min = min(array_keys($plot));
        $max = max(array_keys($plot));
        for ($stem = $min; $stem <= $max; $stem++) {
            if (!isset($plot[$stem])) {
                $plot[$stem] = array();
            }
        }
        ksort($plot);
        // Optionally print the stem and leaf plot
        if ($print === true) {
            $length = max(array_map(function ($stem) {
                return strlen($stem);
            }, array_keys($plot)));
            foreach ($plot as $stem => $leaves) {
                printf("%{$length}d | %s\n", $stem, implode(' ', $leaves));
            }
        }
        return $plot;
    }