# Compute velocity

**URL:** https://discourse.paraview.org/t/compute-velocity/14568
**Category:** ParaView Support
**Created:** [May 7, 2024, 4:49am UTC](https://discourse.paraview.org/t/compute-velocity/14568 "2024-05-07T04:49:36Z")
**Posts on this page:** 20
**Page:** 2

<div class="post-metadata">

### 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: [May 15, 2024, 6:29am UTC](https://discourse.paraview.org/t/compute-velocity/14568/22 "2024-05-15T06:29:06Z")

</div>

Opening your state file it shows:

![a](https://discourse.paraview.org/uploads/default/original/2X/e/e3a9ad0a615d062018cd3e8b5154aea69d04b204.png)

Which is perfectly correct.

---

<div class="post-metadata">

### Author: ![dann](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/d/c6cbf5/32.png) [@dann](https://discourse.paraview.org/u/dann)
#### Post date: [May 15, 2024, 6:49am UTC](https://discourse.paraview.org/t/compute-velocity/14568/23 "2024-05-15T06:49:22Z")

</div>

which magnitude represents the average velocity of the overall slice?

---

<div class="post-metadata">

### 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: [May 15, 2024, 6:50am UTC](https://discourse.paraview.org/t/compute-velocity/14568/24 "2024-05-15T06:50:51Z")

</div>

The average is compute component by component for the U vector, magnitude is the magnitude of the average.

---

<div class="post-metadata">

### Author: ![dann](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/d/c6cbf5/32.png) [@dann](https://discourse.paraview.org/u/dann)
#### Post date: [May 15, 2024, 6:55am UTC](https://discourse.paraview.org/t/compute-velocity/14568/25 "2024-05-15T06:55:36Z")

</div>

so the average velocity is 8.65m/s?

---

<div class="post-metadata">

### 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: [May 15, 2024, 6:57am UTC](https://discourse.paraview.org/t/compute-velocity/14568/26 "2024-05-15T06:57:16Z")

</div>

The average velocity is the vector shown, the magnitude of this average is 8.65

---

<div class="post-metadata">

### Author: ![dann](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/d/c6cbf5/32.png) [@dann](https://discourse.paraview.org/u/dann)
#### Post date: [May 15, 2024, 7:03am UTC](https://discourse.paraview.org/t/compute-velocity/14568/27 "2024-05-15T07:03:00Z")

</div>

![image](https://discourse.paraview.org/uploads/default/original/2X/4/4eee1b5710e4c371716bb5ea3d344bf5686bbfac.jpeg)

Based on the velocity slice here, the maximum velocity around 1.64m/s. But the average magnitude of the velocity is 8.65m/s which is much higher. Can you pls clarify? Thank you

---

<div class="post-metadata">

### 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: [May 15, 2024, 7:06am UTC](https://discourse.paraview.org/t/compute-velocity/14568/28 "2024-05-15T07:06:16Z")

</div>

The problem is not the magnitude, the problem is that the average results is outside of the range of values.

I dont know why the “IntegrateVariable” filter provide incorrect value. Looks like a bug to me.

---

<div class="post-metadata">

### Author: ![dann](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/d/c6cbf5/32.png) [@dann](https://discourse.paraview.org/u/dann)
#### Post date: [May 15, 2024, 7:10am UTC](https://discourse.paraview.org/t/compute-velocity/14568/29 "2024-05-15T07:10:02Z")

</div>

![image](https://discourse.paraview.org/uploads/default/original/2X/b/bac4ee4072acd28e7b97eea18071e43dae509089.png)

I tried a few methods to do the average velocity calculation, and the results look alright for the individual cell, except for the overall slice.

Can i know what is the correct method to calculate the average velocity? Thank you

---

<div class="post-metadata">

### Author: ![dann](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/d/c6cbf5/32.png) [@dann](https://discourse.paraview.org/u/dann)
#### Post date: [May 17, 2024, 7:27am UTC](https://discourse.paraview.org/t/compute-velocity/14568/30 "2024-05-17T07:27:12Z")

</div>

Hi Mathieu,

I just wanted to check in and ask how the bug fixing process for the velocity?

Cheers

---

<div class="post-metadata">

### 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: [May 17, 2024, 7:30am UTC](https://discourse.paraview.org/t/compute-velocity/14568/31 "2024-05-17T07:30:24Z")

</div>

Hi Dann,

First you have to create an issue on [https://gitlab.kitware.com/paraview/paraview/-/issues](https://gitlab.kitware.com/paraview/paraview/-/issues)

Then the issue is to be fixed, please read here to understand how to make it happen:  
[https://discourse.paraview.org/t/how-are-features-and-bug-fixes-incorporated-into-paraview/4735/3](https://discourse.paraview.org/t/how-are-features-and-bug-fixes-incorporated-into-paraview/4735/3)

---

<div class="post-metadata">

### Author: ![dann](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/d/c6cbf5/32.png) [@dann](https://discourse.paraview.org/u/dann)
#### Post date: [May 17, 2024, 7:50am UTC](https://discourse.paraview.org/t/compute-velocity/14568/32 "2024-05-17T07:50:51Z")

</div>

Thanks!

---

<div class="post-metadata">

### Author: ![dann](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/d/c6cbf5/32.png) [@dann](https://discourse.paraview.org/u/dann)
#### Post date: [May 22, 2024, 8:39am UTC](https://discourse.paraview.org/t/compute-velocity/14568/33 "2024-05-22T08:39:44Z")

</div>

Hi Mathieu, I saw ur message under the issue category. can I know the usability is under which category?

---

<div class="post-metadata">

### 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: [May 22, 2024, 8:40am UTC](https://discourse.paraview.org/t/compute-velocity/14568/34 "2024-05-22T08:40:54Z")

</div>

> **[ParaView Support](https://discourse.paraview.org/c/paraview-support/7)**
>
> A place for questions about ParaView usage, building, and installation as well as general discussion about ParaView. If this is your first time here, please read ParaView FAQ before posting.

---

<div class="post-metadata">

### Author: ![dann](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/d/c6cbf5/32.png) [@dann](https://discourse.paraview.org/u/dann)
#### Post date: [May 22, 2024, 8:55am UTC](https://discourse.paraview.org/t/compute-velocity/14568/35 "2024-05-22T08:55:29Z")

</div>

Then I think it’s here which is the paraview support, right ?

---

<div class="post-metadata">

### 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: [May 22, 2024, 8:58am UTC](https://discourse.paraview.org/t/compute-velocity/14568/36 "2024-05-22T08:58:08Z")

</div>

You lost me here. What is your question ?

---

<div class="post-metadata">

### Author: ![dann](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/d/c6cbf5/32.png) [@dann](https://discourse.paraview.org/u/dann)
#### Post date: [May 22, 2024, 9:01am UTC](https://discourse.paraview.org/t/compute-velocity/14568/37 "2024-05-22T09:01:35Z")

</div>

There is an issue when computing velocity mangitude, which I have stated in this post as well.

I want to know the correct way to compute the velocity mangitude for a overall slice. Thanks

---

<div class="post-metadata">

### 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: [May 22, 2024, 9:12am UTC](https://discourse.paraview.org/t/compute-velocity/14568/38 "2024-05-22T09:12:34Z")

</div>

> [@dann](#):
>
> There is an issue when computing velocity mangitude, which I have stated in this post as well.

Indeed, this is why I suggested to open an issue.

---

<div class="post-metadata">

### Author: ![dann](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/d/c6cbf5/32.png) [@dann](https://discourse.paraview.org/u/dann)
#### Post date: [May 22, 2024, 9:22am UTC](https://discourse.paraview.org/t/compute-velocity/14568/39 "2024-05-22T09:22:01Z")

</div>

![Screenshot_20240522_171854](https://discourse.paraview.org/uploads/default/original/2X/2/2b794c14929563c11d1ae38fc20ef99389169335.jpeg)

I did create an issue but you closed it.

---

<div class="post-metadata">

### 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: [May 22, 2024, 9:29am UTC](https://discourse.paraview.org/t/compute-velocity/14568/40 "2024-05-22T09:29:44Z")

</div>

Sorry about that, I did not realize it was the same issue. I’ve reopened it, lets hope someone picks it up.

---

<div class="post-metadata">

### Author: ![dann](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/d/c6cbf5/32.png) [@dann](https://discourse.paraview.org/u/dann)
#### Post date: [May 22, 2024, 9:32am UTC](https://discourse.paraview.org/t/compute-velocity/14568/41 "2024-05-22T09:32:43Z")

</div>

Thank you

[Previous page](https://discourse.paraview.org/t/compute-velocity/14568.md?page=1)

[Next page](https://discourse.paraview.org/t/compute-velocity/14568.md?page=3)