public static function diagonal(array $elements) : self
    {
        $n = count($elements);

        if ($n < 1) {
            throw new InvalidArgumentException('Dimensionality must be'
                . ' greater than 0 on all axes.');
        }

        foreach ($elements as $element) {
            if (!is_int($element) and !is_float($element)) {
                throw new InvalidArgumentException('Diagonal element'
                    . ' must be an integer or float, '
                    . gettype($element) . ' found.');
            }
        }

        $a = [];

        for ($i = 0; $i < $n; $i++) {
            $temp = [];

            for ($j = 0; $j < $n; $j++) {
                $temp[] = $i === $j ? $elements[$i] : 0;
            }

            $a[] = $temp;
        }

        return self::quick($a);
    }