PHPOffice / PhpSpreadsheet

            }

            for ($k = $nct - 1; $k >= 0; --$k) {

                if ($this->s[$k] != 0.0) {

                    for ($j = $k + 1; $j < $nu; ++$j) {

                        $t = 0;

                        for ($i = $k; $i < $this->m; ++$i) {

                            $t += $this->U[$i][$k] * $this->U[$i][$j];

                        }

                        $t = -$t / $this->U[$k][$k];

                        for ($i = $k; $i < $this->m; ++$i) {

                            $this->U[$i][$j] += $t * $this->U[$i][$k];

                        }

                    }

                    for ($i = $k; $i < $this->m; ++$i) {

                        $this->U[$i][$k] = -$this->U[$i][$k];

                    }

                    }

                    $this->QR[$k][$k] += 1.0;

                    // Apply transformation to remaining columns.

                    for ($j = $k + 1; $j < $this->n; ++$j) {

                        $s = 0.0;

                        for ($i = $k; $i < $this->m; ++$i) {

                            $s += $this->QR[$i][$k] * $this->QR[$i][$j];

                        }

                        $s = -$s / $this->QR[$k][$k];

                        for ($i = $k; $i < $this->m; ++$i) {

                            $this->QR[$i][$j] += $s * $this->QR[$i][$k];

                        }

                    }

                }

                $this->Rdiag[$k] = -$nrm;

            }