# \[Error\] before pre.clustering

**URL:** <https://forum.mothur.org/t/error-before-pre-clustering/1183>\
**Category:** Commands in mothur\
**Created:** [January 16, 2013, 2:22pm UTC](https://forum.mothur.org/t/error-before-pre-clustering/1183 "2013-01-16T14:22:29Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Sugi](https://avatars.discourse-cdn.com/v4/letter/s/f17d59/32.png) [@Sugi](https://forum.mothur.org/u/Sugi)\
**Post date:** [January 16, 2013, 2:22pm UTC](https://forum.mothur.org/t/error-before-pre-clustering/1183/1 "2013-01-16T14:22:29Z")

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Dear all,

I’d like to pre cluster my dataset by pre.cluster. In order to do that I need to perform  
unique.seqs thereby I get an --\>

[Error]: You already have a sequence named No\_Name in your fasta file, sequence names must be unique, please correct.

and

[Error]: your sequences are not all the same length. pre.cluster requires sequences to be aligned.

Could someone help???

Kind regards,  
Sugi

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**Author:** ![westcott](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.mothur.org/westcott/32/18_2.png) [@westcott](https://forum.mothur.org/u/westcott)\
**Post date:** [January 16, 2013, 8:07pm UTC](https://forum.mothur.org/t/error-before-pre-clustering/1183/2 "2013-01-16T20:07:10Z")

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Mothur expects sequence names to be unique. It looks like you have more than one sequence named, “No\_Name”. Can you check your fasta file?

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<div class="post-metadata">

**Author:** ![Sugi](https://avatars.discourse-cdn.com/v4/letter/s/f17d59/32.png) [@Sugi](https://forum.mothur.org/u/Sugi)\
**Post date:** [January 17, 2013, 10:56am UTC](https://forum.mothur.org/t/error-before-pre-clustering/1183/3 "2013-01-17T10:56:18Z")

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Hi,

thanks for the help, I could resolve that problem with unique.seqs.

But for pre.clustering I get this Error --\> “your sequences are not all the same length. pre.cluster requires sequences to be aligned”

Thanks for the help

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**Author:** ![pschloss](https://yyz2.discourse-cdn.com/flex036/user_avatar/forum.mothur.org/pschloss/32/4_2.png) [@pschloss](https://forum.mothur.org/u/pschloss)\
**Post date:** [January 17, 2013, 12:17pm UTC](https://forum.mothur.org/t/error-before-pre-clustering/1183/4 "2013-01-17T12:17:50Z")

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Have you run align.seqs at this point in your pipeline?

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<div class="post-metadata">

**Author:** ![Sugi](https://avatars.discourse-cdn.com/v4/letter/s/f17d59/32.png) [@Sugi](https://forum.mothur.org/u/Sugi)\
**Post date:** [January 17, 2013, 4:17pm UTC](https://forum.mothur.org/t/error-before-pre-clustering/1183/5 "2013-01-17T16:17:17Z")

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Thanks, after aligning pre.cluster is possible…