# Error in MrVI differential abundance

**URL:** <https://discourse.scverse.org/t/error-in-mrvi-differential-abundance/2486>\
**Category:** scvi-tools\
**Created:** [September 2, 2024, 1:30pm UTC](https://discourse.scverse.org/t/error-in-mrvi-differential-abundance/2486 "2024-09-02T13:30:10Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Yun-Ching-Chen](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.scverse.org/yun-ching-chen/32/1136_2.png) [@Yun-Ching-Chen](https://discourse.scverse.org/u/Yun-Ching-Chen)\
**Post date:** [September 2, 2024, 1:30pm UTC](https://discourse.scverse.org/t/error-in-mrvi-differential-abundance/2486/1 "2024-09-02T13:30:10Z")

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Hi,

In the function ''differential\_abundance, there is one line which generates error because n\_cov\_values is an integer:  
f"It has {len(n\_cov\_values)} unique values, which exceeds one half of the total samples ({n\_samples})."  
TypeError: object of type ‘int’ has no len()

Thanks,  
Yun-Ching

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**Author:** ![Justin\_Hong](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.scverse.org/justin_hong/32/85_2.png) [@Justin\_Hong](https://discourse.scverse.org/u/Justin_Hong)\
**Post date:** [September 27, 2024, 5:20pm UTC](https://discourse.scverse.org/t/error-in-mrvi-differential-abundance/2486/2 "2024-09-27T17:20:51Z")

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Thanks for raising this, we will make this fix asap!