# sub.sample quality file

**URL:** <https://forum.mothur.org/t/sub-sample-quality-file/3034>\
**Category:** Feature requests\
**Created:** [November 17, 2016, 2:27pm UTC](https://forum.mothur.org/t/sub-sample-quality-file/3034 "2016-11-17T14:27:21Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Angrist](https://avatars.discourse-cdn.com/v4/letter/a/53a042/32.png) [@Angrist](https://forum.mothur.org/u/Angrist)\
**Post date:** [November 17, 2016, 2:27pm UTC](https://forum.mothur.org/t/sub-sample-quality-file/3034/1 "2016-11-17T14:27:21Z")

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Hey,

Would it be possible to include the quality file as an option in the sub.sample command?  
I currently have huge HiSeq datasets and it would be amazing if in the future this option would be available for extracting small proportions of the fasta & quality file to optimize my pipeline before running the real datasets.

Cheers,  
Uli

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<div class="post-metadata">

**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:** [November 17, 2016, 6:49pm UTC](https://forum.mothur.org/t/sub-sample-quality-file/3034/2 "2016-11-17T18:49:42Z")

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If you’re on a linux computer you could do something like…

```nohighlight
head -n 40000 my.fastq > my.subsample.fastq

```

You’d run this from the command prompt (not in mothur) and it would return the first 10000 sequences from your fastq file and put them in a file called my.subsample.fastq.

Pat

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<div class="post-metadata">

**Author:** ![Angrist](https://avatars.discourse-cdn.com/v4/letter/a/53a042/32.png) [@Angrist](https://forum.mothur.org/u/Angrist)\
**Post date:** [November 30, 2016, 11:52am UTC](https://forum.mothur.org/t/sub-sample-quality-file/3034/3 "2016-11-30T11:52:21Z")

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Thanks,  
that helped!