    s1 = vtkHyperStreamline()
    s1.SetInputData(ptLoad.GetOutput())
    s1.SetStartPosition(9, 9, -9)
    s1.IntegrateMinorEigenvector()
    s1.SetMaximumPropagationDistance(18.0)
    s1.SetIntegrationStepLength(0.1)
--
    s2 = vtkHyperStreamline()
    s2.SetInputData(ptLoad.GetOutput())
    s2.SetStartPosition(-9, -9, -9)
    s2.IntegrateMinorEigenvector()
    s2.SetMaximumPropagationDistance(18.0)
    s2.SetIntegrationStepLength(0.1)
--
    s3 = vtkHyperStreamline()
    s3.SetInputData(ptLoad.GetOutput())
    s3.SetStartPosition(9, -9, -9)
    s3.IntegrateMinorEigenvector()
    s3.SetMaximumPropagationDistance(18.0)
    s3.SetIntegrationStepLength(0.1)
--
    s4 = vtkHyperStreamline()
    s4.SetInputData(ptLoad.GetOutput())
    s4.SetStartPosition(-9, 9, -9)
    s4.IntegrateMinorEigenvector()
    s4.SetMaximumPropagationDistance(18.0)
    s4.SetIntegrationStepLength(0.1)
