vtkNew<vtkDoubleArray> xArray;
    xArray->SetNumberOfComponents(1);
    xArray->SetName("x");

    vtkNew<vtkDoubleArray> yArray;
    yArray->SetNumberOfComponents(1);
    yArray->SetName("y");

    vtkNew<vtkDoubleArray> zArray;
    zArray->SetNumberOfComponents(1);
    zArray->SetName("z");
    vtkPolyData * polydata = reader->GetOutput();

        for (vtkIdType i = 0; i < polydata->GetNumberOfPoints(); i++)
        {
            double p[3];

            polydata->GetPoint(i, p);

            xArray->InsertNextValue(p[0]);
            yArray->InsertNextValue(p[1]);
            zArray->InsertNextValue(p[2]);
        }

    vtkNew<vtkTable> datasetTable;
    datasetTable->AddColumn(xArray);
    datasetTable->AddColumn(yArray);
    datasetTable->AddColumn(zArray);

    vtkNew<vtkPCAStatistics> pcaStatistics;
    pcaStatistics->SetInputData(vtkStatisticsAlgorithm::INPUT_DATA, datasetTable);

    pcaStatistics->SetColumnStatus("x", 1);
    pcaStatistics->SetColumnStatus("y", 1);
    pcaStatistics->SetColumnStatus("z", 1);

    pcaStatistics->RequestSelectedColumns();
    pcaStatistics->SetDeriveOption(true);
    pcaStatistics->Update();

    vtkNew<vtkDoubleArray> eigenvalues;
    pcaStatistics->GetEigenvalues(eigenvalues);

    vtkNew<vtkDoubleArray> eigenvectors;

    pcaStatistics->GetEigenvectors(eigenvectors);
    vtkNew<vtkDoubleArray> evec1;
    pcaStatistics->GetEigenvector(0, evec1);

    vtkNew<vtkDoubleArray> evec2;
    pcaStatistics->GetEigenvector(1, evec2);


    vtkNew<vtkDoubleArray> evec3;
    pcaStatistics->GetEigenvector(2, evec3);