# Slice filter of a Tecplot \*.plt file

**URL:** https://discourse.paraview.org/t/slice-filter-of-a-tecplot-plt-file/15997
**Category:** ParaView Support
**Created:** [January 18, 2025, 1:53pm UTC](https://discourse.paraview.org/t/slice-filter-of-a-tecplot-plt-file/15997 "2025-01-18T13:53:05Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![dweyburne](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/d/41988e/32.png) [@dweyburne](https://discourse.paraview.org/u/dweyburne)
#### Post date: [January 18, 2025, 1:53pm UTC](https://discourse.paraview.org/t/slice-filter-of-a-tecplot-plt-file/15997/1 "2025-01-18T13:53:06Z")

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A colleague sent me a Tecplot \*.plt file consisting of the CVD results for a NACA0012 2D simulation. When I take a slice using the slice filter and save as csv data, I end up with a ~29000 row file of velocities. The mesh is only ~2000 in the slice direction. Plots of the velocities look fine. However, when I differentiate the data twice to look at the viscous regions, I end up with spikes all trough the data instead of a smooth curve. I think ParaView is pulling multiple data points from each cell and then trying to differentiate the cell values which blow up. Any ideas on how to pull data so the derivative do not blow up?

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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 20, 2025, 9:47am UTC](https://discourse.paraview.org/t/slice-filter-of-a-tecplot-plt-file/15997/2 "2025-01-20T09:47:54Z")

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Please share your data.

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### Author: ![dweyburne](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/d/41988e/32.png) [@dweyburne](https://discourse.paraview.org/u/dweyburne)
#### Post date: [January 22, 2025, 2:27pm UTC](https://discourse.paraview.org/t/slice-filter-of-a-tecplot-plt-file/15997/3 "2025-01-22T14:27:02Z")

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I tried to upload but it crashed twice. The file is large, 6.5 gb. It is the results of the simulation of laminar flow over a NACA0012 airfoil using an unstructured 4096 × 2048 mesh file from NASA/TM–2016–219003 by R. C. Swanson and S. Langer.

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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 23, 2025, 8:18am UTC](https://discourse.paraview.org/t/slice-filter-of-a-tecplot-plt-file/15997/4 "2025-01-23T08:18:43Z")

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> [@dweyburne](#):
>
> I tried to upload but it crashed twice.

Did you download it from somewhere ? Maybe you could share that.