tensors ?

[IdaRlt]

Hello,
I wonder if anybody could help with my problem.
I would like to export tensor data as a point data in a RectilinearGrid, but the gridToVTK only accept scalar data.
I tried to use the low-level example and adapt it for tensors but it seems that any tuple data is understood as a vector and should have a size of 3. Did I miss something ? Is there another way to export tensor data ?
Ida.