PHPOffice / PhpSpreadsheet

                    $p = $p / $r;

                    $q = $q / $r;

                    // Row modification

                    for ($j = $n - 1; $j < $nn; ++$j) {

                        $z = $this->H[$n - 1][$j];

                        $this->H[$n - 1][$j] = $q * $z + $p * $this->H[$n][$j];

                        $this->H[$n][$j] = $q * $this->H[$n][$j] - $p * $z;

                    }

                    // Column modification

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

                        $z = $this->H[$i][$n - 1];

                        $this->H[$n][$j] = $q * $this->H[$n][$j] - $p * $z;

                    }

                    // Column modification

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

                        $z = $this->H[$i][$n - 1];

                        $this->H[$i][$n - 1] = $q * $z + $p * $this->H[$i][$n];

                        $this->H[$i][$n] = $q * $this->H[$i][$n] - $p * $z;

                    }

                    // Accumulate transformations

                    for ($i = $low; $i <= $high; ++$i) {

                        $z = $this->V[$i][$n - 1];

                        $this->H[$i][$n] = $q * $this->H[$i][$n] - $p * $z;

                    }

                    // Accumulate transformations

                    for ($i = $low; $i <= $high; ++$i) {

                        $z = $this->V[$i][$n - 1];

                        $this->V[$i][$n - 1] = $q * $z + $p * $this->V[$i][$n];

                        $this->V[$i][$n] = $q * $this->V[$i][$n] - $p * $z;

                    }

                // Complex pair

                } else {

                    $this->d[$n - 1] = $x + $p;