Error with only numeric values in first column of metadata.tsv (with qiime2-2018.2)


I encountered a minor issue with the handling of metadata.tsv file in qiime2-2018.2.

I had a problem when using only numeric values in the first column (#SampleID) of the metadata.tsv (the problem did not occur in release 2017.12).

I imported and demultiplexed fastq files according to the Moving Pictures Tutorial. After demultiplexing, I applied qiime quality-filter q-score and used qiime metadata tabulate to visualize the outcome of filtering (also according to the moving pictures tutorial)

After using qiime metadata tabulate, I encountered the following error:

There was an issue with viewing the artifact demux_filtered_stats.qza as QIIME 2 Metadata:

Detected non-string metadata ID: 101

(101 is the name of my first sample)

When testing the metadata.tsv file with Keemei, no problem was indicated.

I solved this problem by adding letters to the numeric values of the #SampleID column (changing 101 to sample101). It did not matter, If I used the optional comment directive #q2:types in the #SampleID column or not (as described in the Metadata Tutorial).

Maybe this helps, if people encounter the same problem.



Thanks for the report, Martin. I wonder if that’s something Keemei should detect, of if this is an issue with the new metadata functionality.

Let’s see what @jairideout suggests!


Hi @Martin! The metadata file itself is fine (along with Keemei’s validation) – it’s acceptable to use sample IDs that are entirely numeric. However, it looks like you discovered an issue with viewing the stats file produced by qiime quality-filter q-score as metadata. I’ve created an issue to fix the issue in q2-quality-filter. In the meantime, the workaround you posted is probably the best way forward, thanks for providing that for others with the same issue.

We’ll follow up here when the issue is fixed in a release!

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