# Questions about rake angle in the slip\_invert.cfg

**URL:** https://community.geodynamics.org/t/questions-about-rake-angle-in-the-slip-invert-cfg/2147
**Category:** PyLith
**Created:** [December 27, 2021, 2:24pm UTC](https://community.geodynamics.org/t/questions-about-rake-angle-in-the-slip-invert-cfg/2147 "2021-12-27T14:24:33Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![luxiaokong](https://avatars.discourse-cdn.com/v4/letter/l/3d9bf3/32.png) [@luxiaokong](https://community.geodynamics.org/u/luxiaokong)
#### Post date: [December 27, 2021, 2:24pm UTC](https://community.geodynamics.org/t/questions-about-rake-angle-in-the-slip-invert-cfg/2147/1 "2021-12-27T14:24:33Z")

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Dear Pylith team,

I wonder how the rake angle in the slip\_invert.cfg file in the examples/3d/subduction is specified and what is the meaning it represents?

Thank you in advance.

Nick

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### Author: ![baagaard](https://yyz2.discourse-cdn.com/flex036/user_avatar/community.geodynamics.org/baagaard/32/615_2.png) [@baagaard](https://community.geodynamics.org/u/baagaard)
#### Post date: [December 27, 2021, 4:45pm UTC](https://community.geodynamics.org/t/questions-about-rake-angle-in-the-slip-invert-cfg/2147/2 "2021-12-27T16:45:29Z")

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The inversion assumes a spatially uniform, fixed value for the rake angle. The value is a Pyre property with a default value of 90.0 degrees (reverse slip). You can use the `--rake=45.0*degree` command line argument to change it to a different value.