# Evenly spaced streamlines 2D error

**URL:** https://discourse.paraview.org/t/evenly-spaced-streamlines-2d-error/10416
**Category:** ParaView Support
**Tags:** vtk
**Created:** [September 27, 2022, 6:33am UTC](https://discourse.paraview.org/t/evenly-spaced-streamlines-2d-error/10416 "2022-09-27T06:33:41Z")
**Posts on this page:** 5
**Page:** 1

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### Author: ![jskang](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/j/c2a13f/32.png) [@jskang](https://discourse.paraview.org/u/jskang)
#### Post date: [September 27, 2022, 6:33am UTC](https://discourse.paraview.org/t/evenly-spaced-streamlines-2d-error/10416/1 "2022-09-27T06:33:41Z")

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Hello.  
I have an error when I try to use EvenlySpacedStreamlines2D.  
I’m trying to show pvtu 3D cell data with EvenlySpacedStreamlines2D.  
So I tried following methods.

1. Open data.
2. Filter - CellDatatoPointData
3. Filter - Slice - Z normal
4. Filter - Calculator - “MS\_B(T)\_X”\*iHat+“MS\_B(T)\_Y”\*jHat
5. Filter - EvenlySpacedStreamlines2D

Then error message is opened with no output data.  
This is the error message.

ERROR: In C:\glr\builds\paraview\paraview-ci\build\superbuild\paraview\src\VTK\Common\ExecutionModel\vtkExecutive.cxx, line 753  
vtkPVCompositeDataPipeline (0000010D3E253180): Algorithm vtkEvenlySpacedStreamlines2D(0000010D6FBAA600) returned failure for request: vtkInformation (0000010D78635990)  
Debug: Off  
Modified Time: 24541029  
Reference Count: 1  
Registered Events: (none)  
Request: REQUEST\_DATA  
FORWARD\_DIRECTION: 0  
ALGORITHM\_AFTER\_FORWARD: 1  
FROM\_OUTPUT\_PORT: 0

I tried in Paraview 5.10.1, Paraview 5.11.0, and Paraview Master 5.11.0-RC1.  
And no success.

I attached my pvtu file.  
[Air2.zip](https://discourse.paraview.org/uploads/short-url/v1qU3gwc3c83tIHSibPR06Yha1E.zip) (2.0 MB)

Any reply would be helpful.  
Thank you.

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### Author: ![Kenichiro-Yoshimi](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/k/ecc23a/32.png) [@Kenichiro-Yoshimi](https://discourse.paraview.org/u/Kenichiro-Yoshimi)
#### Post date: [September 29, 2022, 3:10am UTC](https://discourse.paraview.org/t/evenly-spaced-streamlines-2d-error/10416/2 "2022-09-29T03:10:09Z")

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Hi,

After cutting at z=0.0005, specify **Start Position** in `EvenlySpacedStreamlines2D` as  
` -0.065506252,-0.00444358875,0.0005`  
I was able to draw streamlines on only one piece of the surface. If the surface is divided into several pieces, it may be necessary to apply `EvenlySpacedStreamlines2D` to each piece.

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### Author: ![jskang](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/j/c2a13f/32.png) [@jskang](https://discourse.paraview.org/u/jskang)
#### Post date: [September 29, 2022, 4:10am UTC](https://discourse.paraview.org/t/evenly-spaced-streamlines-2d-error/10416/3 "2022-09-29T04:10:24Z")

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Dear Kyoshimi,

Thank you very much!  
It was worked. But still I can’t draw other pieces, even though I set Start Position in EvenlySpacedStreamlins2D.  
I will keep trying.  
Thank you.

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### Author: ![Kenichiro-Yoshimi](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/k/ecc23a/32.png) [@Kenichiro-Yoshimi](https://discourse.paraview.org/u/Kenichiro-Yoshimi)
#### Post date: [September 29, 2022, 10:39am UTC](https://discourse.paraview.org/t/evenly-spaced-streamlines-2d-error/10416/4 "2022-09-29T10:39:13Z")

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Hi,

I have automated this with a python script.  
[streams.py](https://discourse.paraview.org/uploads/short-url/3FWRhZUnOxP83Kqdvkpa3iWSJ1c.py) (5.7 KB)

To use it, place `streams.py` in the same folder as `vg_VolTs_VTK_Air2_5.pvtu` and in ParaView 5.10.1, specify `streams.py` from “ **File \> Load State…** ”.

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### Author: ![jskang](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/j/c2a13f/32.png) [@jskang](https://discourse.paraview.org/u/jskang)
#### Post date: [September 30, 2022, 12:35am UTC](https://discourse.paraview.org/t/evenly-spaced-streamlines-2d-error/10416/5 "2022-09-30T00:35:11Z")

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Dear, Kyoshimi

Amazing!  
I didn’t know about “Connectivity” and “Threshold” filters.  
Actually, I modified the part of file location in your streams.py file. Then it worked.

 ![image](https://discourse.paraview.org/uploads/default/original/2X/9/9d0fce9725fe359eeaacee52197462cdedba5baa.png)

Maybe I should study those filters and your script.  
Thank you very much.