# Annotate non-symmetric second order tensors with components XX, YY, ...

**URL:** https://discourse.paraview.org/t/annotate-non-symmetric-second-order-tensors-with-components-xx-yy/8754
**Category:** ParaView Support
**Created:** [January 11, 2022, 12:21pm UTC](https://discourse.paraview.org/t/annotate-non-symmetric-second-order-tensors-with-components-xx-yy/8754 "2022-01-11T12:21:38Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![fredrik](https://discourse.paraview.org/user_avatar/discourse.paraview.org/fredrik/32/5351_2.png) [@fredrik](https://discourse.paraview.org/u/fredrik)
#### Post date: [January 11, 2022, 12:21pm UTC](https://discourse.paraview.org/t/annotate-non-symmetric-second-order-tensors-with-components-xx-yy/8754/1 "2022-01-11T12:21:38Z")

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ParaView automatically labels data components with `X`, `Y`, `Z` for vectors, and with `XX`, `YY`, `ZZ`, `XY`, `YZ`, `XZ` for 2nd order tensors (length-6 vectors in the VTK file), see screenshot:

 ![symmetric-tensors](https://discourse.paraview.org/uploads/default/original/2X/9/9fec7cc99331bc54d7ef5dbb8bfaa4de924ff0cd.png)

I wonder why this is not implemented also for non-symmetric tensors (length-9 vectors in the VTK file)? Currently those components are just enumerated 0-8 instead:

 ![tensors](https://discourse.paraview.org/uploads/default/original/2X/5/5d261dc0553cb2e6131fb5e397198ea22ee808bc.png)

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Example VTK file:  
[test\_tensors.vtu](https://discourse.paraview.org/uploads/short-url/1caH6dUZrgvnHxBjiaWdFvxE1o3.vtu) (5.1 KB)

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### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [January 11, 2022, 12:35pm UTC](https://discourse.paraview.org/t/annotate-non-symmetric-second-order-tensors-with-components-xx-yy/8754/2 "2022-01-11T12:35:40Z")

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Because it was not implemented, that seems easy to add though.

[https://gitlab.kitware.com/paraview/paraview/-/blob/2a2273e8849869011628a10f49468f34a268ed8a/VTKExtensions/Core/vtkPVPostFilter.cxx#L164](https://gitlab.kitware.com/paraview/paraview/-/blob/2a2273e8849869011628a10f49468f34a268ed8a/VTKExtensions/Core/vtkPVPostFilter.cxx#L164)

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### Author: ![fredrik](https://discourse.paraview.org/user_avatar/discourse.paraview.org/fredrik/32/5351_2.png) [@fredrik](https://discourse.paraview.org/u/fredrik)
#### Post date: [January 11, 2022, 12:37pm UTC](https://discourse.paraview.org/t/annotate-non-symmetric-second-order-tensors-with-components-xx-yy/8754/3 "2022-01-11T12:37:28Z")

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Right, was wondering if it was a conscious choice to exclude it. I will try to submit a patch.

Edit: [https://gitlab.kitware.com/paraview/paraview/-/merge\_requests/5442](https://gitlab.kitware.com/paraview/paraview/-/merge_requests/5442)