public function PHPExcel_Shared_JAMA_QRDecomposition::solve in Loft Data Grids 6.2

Same name and namespace in other branches

1. 7.2 vendor/phpoffice/phpexcel/Classes/PHPExcel/Shared/JAMA/QRDecomposition.php \PHPExcel_Shared_JAMA_QRDecomposition::solve()

* Least squares solution of A*X = B * *

Parameters

Matrix $B A Matrix with as many rows as A and any number of columns.: * @return Matrix Matrix that minimizes the two norm of Q*R*X-B.

File

vendor/phpoffice/phpexcel/Classes/PHPExcel/Shared/JAMA/QRDecomposition.php, line 194

Class

PHPExcel_Shared_JAMA_QRDecomposition

@package JAMA

Code

public function solve($B) {
  if ($B
    ->getRowDimension() == $this->m) {
    if ($this
      ->isFullRank()) {

      // Copy right hand side
      $nx = $B
        ->getColumnDimension();
      $X = $B
        ->getArrayCopy();

      // Compute Y = transpose(Q)*B
      for ($k = 0; $k < $this->n; ++$k) {
        for ($j = 0; $j < $nx; ++$j) {
          $s = 0.0;
          for ($i = $k; $i < $this->m; ++$i) {
            $s += $this->QR[$i][$k] * $X[$i][$j];
          }
          $s = -$s / $this->QR[$k][$k];
          for ($i = $k; $i < $this->m; ++$i) {
            $X[$i][$j] += $s * $this->QR[$i][$k];
          }
        }
      }

      // Solve R*X = Y;
      for ($k = $this->n - 1; $k >= 0; --$k) {
        for ($j = 0; $j < $nx; ++$j) {
          $X[$k][$j] /= $this->Rdiag[$k];
        }
        for ($i = 0; $i < $k; ++$i) {
          for ($j = 0; $j < $nx; ++$j) {
            $X[$i][$j] -= $X[$k][$j] * $this->QR[$i][$k];
          }
        }
      }
      $X = new PHPExcel_Shared_JAMA_Matrix($X);
      return $X
        ->getMatrix(0, $this->n - 1, 0, $nx);
    }
    else {
      throw new PHPExcel_Calculation_Exception(self::MatrixRankException);
    }
  }
  else {
    throw new PHPExcel_Calculation_Exception(PHPExcel_Shared_JAMA_Matrix::MatrixDimensionException);
  }
}