# 2D Euler Vortex: partition error

**URL:** <https://pyfr.discourse.group/t/2d-euler-vortex-partition-error/609>\
**Category:** Errors\
**Tags:** mesh\
**Created:** [22 May 2022 12:21 UTC](https://pyfr.discourse.group/t/2d-euler-vortex-partition-error/609 "2022-05-22T12:21:18Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![ManuSaiVenkataRatnam](https://yyz2.discourse-cdn.com/free1/user_avatar/pyfr.discourse.group/manusaivenkataratnam/32/364_2.png) [@ManuSaiVenkataRatnam](https://pyfr.discourse.group/u/ManuSaiVenkataRatnam)\
**Post date:** [22 May 2022 12:21 UTC](https://pyfr.discourse.group/t/2d-euler-vortex-partition-error/609/1 "2022-05-22T12:21:18Z")

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Hello Everyone!  
I am very new to pyFr, need to learn it for a project.

1. When going through the first example of 2D euler equation after executing step 5, got the error as shown in the image.  
Can anyone guide me what needs to be done here?
2. I am running pyfr in bash (gitbash) terminal, is it okay or need to use windows command prompt?

![euler equation partition error](https://global.discourse-cdn.com/free1/uploads/pyfr/original/1X/b1726c4744b19a0da971ab3098268040325596f1.jpeg)

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**Author:** ![fdw](https://avatars.discourse-cdn.com/v4/letter/f/a587f6/32.png) [@fdw](https://pyfr.discourse.group/u/fdw)\
**Post date:** [22 May 2022 12:56 UTC](https://pyfr.discourse.group/t/2d-euler-vortex-partition-error/609/2 "2022-05-22T12:56:37Z")

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The error message is self-explanatory. You are missing a required argument, `outd` as per:

```auto
$ pyfr partition --help
usage: pyfr partition [-h] [-p {metis,scotch}] [-r RNUMF] [-e shape:weight] [--popt key:value] np mesh [soln ...] outd

positional arguments:
np number of partitions or a colon delimited list of weights
mesh input mesh file
soln input solution files
outd output directory

```

Regards, Freddie.

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**Author:** ![p.vincent](https://yyz2.discourse-cdn.com/free1/user_avatar/pyfr.discourse.group/p.vincent/32/225_2.png) [@p.vincent](https://pyfr.discourse.group/u/p.vincent)\
**Post date:** [22 May 2022 15:59 UTC](https://pyfr.discourse.group/t/2d-euler-vortex-partition-error/609/3 "2022-05-22T15:59:04Z")

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As @fdw said you are missing the output directory for the partitioned mesh. The example sets this as ‘.’ (pyfr partition 2 euler\_vortex\_2d.pyfrm .) thus overwriting the original mesh with the partitioned version.