Demux summarize issue

HI, I was running the data using the qiime-2017.5 and just had an issue with the demux summarize, see below

(qiime2-2017.5) Jinbings-iMac:qiime2 jinbingbai$ qiime demux summarize \
>   --i-data demux-paired-end.qza \
>   --o-visualization demuxtest.qzv

Plugin error from demux:

  Observed sequences of length 300 and 299 while generating a random
  subsample of sequences. Inconsistent length sequences are not
  supported in this visualization at this time.

Debug info has been saved to /var/folders/sd/vlrr9d916gg5qj3yzzf3srfw0000gn/T/qiime2-q2cli-err-qd1oud3m.log.

I never had an issue with this before when I was running the same data in other versions of QIIME2. Please help me~


Hi @Bing,

This is related to a new error check just added in QIIME 2 2017.5 that ensures the subsample of sequences selected for the summarize quality plot are all the same length (otherwise, the statistics in that plot don’t really make sense). Unfortunately, we missed the cased where the difference in sequence lengths is basically negligible (e.g. 1-5 bases, what you are seeing here).

We have created a new issue to fix this — one option we are leaning towards is truncating the length of the subsampled sequences to the shortest observed length. Another option will be to specify some kind of threshold to tolerate (the 1-5 example above).

In the meantime, you could try running this more than once, because the check is only performed on the sequences in the random subsample (and it is random every time you run the command). You could also decrease the size of the subsample, but that has an impact on the 7-number distributions displayed in the plot.

Hope that helps, and let us know if you have any thoughts about this situation, we would appreciate the input!

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This issue was resolved in QIIME 2 2017.6! :tada:

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