[vtkusers] filter to compute the norm of a tensor

[Shiyuan]

Hi all,
     I used a vtkXMLUnstructuredGridReader to read in a dataset which
contains three PointArrary, one is a vector and other two are tensors.
 Now, I want to compute the norm of one of the tensor and then use it for
the color mapping.  Is there such filter in vtk? If not, any examples I can
refer to for writing such a new filter? I also need to select one of the
PointArray  as the input to the filter? For vtkUnstructuredGridReader,
 there seems to be a function called SetTensorName to allow us to select
which tensor to extract, but I don't see such function exist in
vtkXMLUnstructuredGridReader.

I am new to vtk. Any help is greatly appreciated.

Shiyuan
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.vtk.org/pipermail/vtkusers/attachments/20130216/4a755a34/attachment.htm>