I am trying to visualize wake field of a propeller.
the field data is written in Tecplot format and have 3 scalar; u, v, w.

After loading with vtkTecplotReader, I would like to visualize v, w field with glyph after making vector field through vtkArrayCalculator.

my code goes as follows:

vtkTecplotReader reader = new vtkTecplotReader();
reader.SetFileName("wake.dat");
reader.Update();

vtkMultiBlockDataSet multiBDS = new vtkMultiBlockDataSet();
multiBDS = reader.GetOutput();

// vector glyph
vtkArrayCalculator calculator = new vtkArrayCalculator();
for (uint i = 0; i < multiBDS.GetNumberOfBlocks(); i++)
{
    vtkPointSet block;
    if (multiBDS.GetBlock(i).IsA("vtkStructuredGrid") == 1)
    {
        block = multiBDS.GetBlock(i) as vtkStructuredGrid;
    }
    else
    {
        block = multiBDS.GetBlock(i) as vtkUnstructuredGrid;
    }
    calculator.AddInputData(block);
}

calculator.AddScalarArrayName("u", 0);
calculator.AddScalarArrayName("v", 0);
calculator.AddScalarArrayName("w", 0);
calculator.SetFunction("jHat*v + kHat*w");
calculator.SetResultArrayName("wake");
calculator.Update();

vtkGlyph2D glyph2D = new vtkGlyph2D();
glyph2D.SetSourceConnection(calculator.GetOutputPort());
glyph2D.Update();

vtkPolyDataMapper glyph2DMapper = new vtkPolyDataMapper();
glyph2DMapper.SetInputConnection(glyph2D.GetOutputPort());
glyph2DMapper.Update();

vtkActor glyph2DActor = new vtkActor();
glyph2DActor.SetMapper(glyph2DMapper);
glyph2DActor.GetProperty().SetColor(0, 0, 0);

But with this code, I got the following warning

vtkDemandDrivenPipeline:677    ERR| vtkCompositeDataPipeline (0000024358F719B0): Input port 0 of algorithm vtkGlyph2D (0000024358F22C10) has 0 connections but is not optional

Any comments and advice would be grateful.