# Making a tensor from scalars
**URL:** https://discourse.paraview.org/t/making-a-tensor-from-scalars/2914
**Category:** ParaView Support
**Tags:** python
**Created:** [November 5, 2019, 4:39pm UTC](https://discourse.paraview.org/t/making-a-tensor-from-scalars/2914 "2019-11-05T16:39:40Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@Mike](https://discourse.paraview.org/u/Mike)
#### Post date: [November 5, 2019, 4:39pm UTC](https://discourse.paraview.org/t/making-a-tensor-from-scalars/2914/1 "2019-11-05T16:39:40Z")
Dear ParaView Community,
I have the components of a tensor as scalar variables, and I would like to combine them into a single tensor variable so I can use the Tensor Glyph filter. The ParaView [Wiki](https://www.paraview.org/Wiki/Python_calculator_and_programmable_filter) indicates that this can be done using a Programmable Filter, but when I use the suggested script, I get the following error: “TypeError: Could not find a suitable VTK type for object.” Could someone please explain how to fix the error? Here is the script from the Wiki:
```
from paraview.vtk.numpy_interface import dataset_adapter as dsa
import numpy
def make_tensor(xx,yy,zz, xy, yz, xz):
t = numpy.vstack([xx,yy,zz,xy, yz, xz]).transpose().view(dsa.VTKArray)
t.DataSet = xx.DataSet
t.Association = xx.Association
return t
xx = inputs[0].PointData["sigma_xx"]
yy = inputs[0].PointData["sigma_yy"]
zz = inputs[0].PointData["sigma_zz"]
xy = inputs[0].PointData["sigma_xy"]
yz = inputs[0].PointData["sigma_yz"]
xz = inputs[0].PointData["sigma_xz"]
output.PointData.append(make_tensor(xx,yy,zz,xy,yz,xz), "tensor")
```
Best regards,
Mike
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [November 7, 2019, 9:28am UTC](https://discourse.paraview.org/t/making-a-tensor-from-scalars/2914/2 "2019-11-07T09:28:23Z")
Can you share your input data ?
You need to make sure that your data contains `sigma_xx` and other arrays.
---
### Author:  [@lvelt](https://discourse.paraview.org/u/lvelt)
#### Post date: [September 27, 2021, 2:08pm UTC](https://discourse.paraview.org/t/making-a-tensor-from-scalars/2914/3 "2021-09-27T14:08:32Z")
Hello,
I have the same problem as Mike described. Using
> output.PointData.append(xx, “test”)
is working so I am sure that the data is called successfully. However, I am not able to create a tensor using the function from the Wiki.
Best Regards
Lennart
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [September 28, 2021, 2:16pm UTC](https://discourse.paraview.org/t/making-a-tensor-from-scalars/2914/6 "2021-09-28T14:16:35Z")
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [September 28, 2021, 2:16pm UTC](https://discourse.paraview.org/t/making-a-tensor-from-scalars/2914/7 "2021-09-28T14:16:52Z")
Can you share the code that is not working in your case ?
---
### Author:  [@mckel](https://discourse.paraview.org/u/mckel)
#### Post date: [February 10, 2022, 9:16am UTC](https://discourse.paraview.org/t/making-a-tensor-from-scalars/2914/8 "2022-02-10T09:16:53Z")
I had the same issue as Lennart. Figured out it was related to the input data being a `vtkMultiBlockDataSet`. Adding a `MergeBlocks` filter helped.