# Is it possible to let the data2 denosie choose the best parameter for trim and trunc? Thanks

**URL:** https://forum.qiime2.org/t/is-it-possible-to-let-the-data2-denosie-choose-the-best-parameter-for-trim-and-trunc-thanks/5618
**Category:** Ideas and Suggestions
**Created:** [August 16, 2018, 3:32pm UTC](https://forum.qiime2.org/t/is-it-possible-to-let-the-data2-denosie-choose-the-best-parameter-for-trim-and-trunc-thanks/5618 "2018-08-16T15:32:19Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![archie](https://forum.qiime2.org/letter_avatar_proxy/v4/letter/a/ba9def/32.png) [@archie](https://forum.qiime2.org/u/archie)
#### Post date: [August 16, 2018, 3:32pm UTC](https://forum.qiime2.org/t/is-it-possible-to-let-the-data2-denosie-choose-the-best-parameter-for-trim-and-trunc-thanks/5618/1 "2018-08-16T15:32:19Z")

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Is it possible to let the data2 denosie choose the best parameter for the following options? Thanks.

--p-trim-left-f 7   
--p-trim-left-r 7   
--p-trunc-len-f 260   
--p-trunc-len-r 200 \

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### Author: ![Nicholas\_Bokulich](https://forum.qiime2.org/user_avatar/forum.qiime2.org/nicholas_bokulich/32/19937_2.png) [@Nicholas\_Bokulich](https://forum.qiime2.org/u/Nicholas_Bokulich)
#### Post date: [August 16, 2018, 5:18pm UTC](https://forum.qiime2.org/t/is-it-possible-to-let-the-data2-denosie-choose-the-best-parameter-for-trim-and-trunc-thanks/5618/2 "2018-08-16T17:18:15Z")

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Hi @archie,  
No — there is not currently a way to allow dada2 to automatically select the "best" parameters. That's actually a fairly tricky and subjective question! Much does depend on user input, e.g., trimming is often used to remove primers as well as any low-quality bases at the 5' end, and truncation choice can often be complex (e.g., balancing error trimming vs. quality decisions).

Cool idea though!

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### Author: ![archie](https://forum.qiime2.org/letter_avatar_proxy/v4/letter/a/ba9def/32.png) [@archie](https://forum.qiime2.org/u/archie)
#### Post date: [August 16, 2018, 6:44pm UTC](https://forum.qiime2.org/t/is-it-possible-to-let-the-data2-denosie-choose-the-best-parameter-for-trim-and-trunc-thanks/5618/3 "2018-08-16T18:44:42Z")

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Thank you so much for the replying.