And when i run the following command:
qiime dada2 denoise-paired --i-demultiplexed-seqs demux-paired-end.qza --p-trim-left-f 0 --p-trim-left-r 0 --p-trunc-len-f 40 --p-trunc-len-r 80 --o-representative-sequences rep-seqs-dada2.qza --o-table table-dada2.qza --output-dir denoising --p-n-threads 24
I get this error:
Remove chimeras (method = consensus)
Error in isBimeraDenovoTable(unqs[[i]], …, verbose = verbose) :
Input must be a valid sequence table.
Calls: removeBimeraDenovo -> isBimeraDenovoTable
Execution halted
The import in qiime looks OK and was done with the following commands (and outputs):
qiime tools import --type ‘SampleData[PairedEndSequencesWithQuality]’ --input-path fastq_files --input-format CasavaOneEightSingleLanePerSampleDirFmt --output-path demux-paired-end.qza
Imported fastq_files as CasavaOneEightSingleLanePerSampleDirFmt to demux-paired-end.qza
Hi Nicolas,
yes, I saw this explanation before.
but the quality scores of my reads are really good.
and this is strange to me that i need to trim my reads so much to be able to join them: denoise-paired with the following parameters: -p-trim-left-f 20 --p-trim-left-r 20 --p-trunc-len-f 100 p-trunc-len-r 150
you must be truncating too much. Use longer truncation lengths to achieve sufficient joining between your paired-end reads. If this is not possible, you will need to process only your forward reads as if they are single-end reads.
I tried to trim less bases : -p-trim-left-f 20 --p-trim-left-r 20 --p-trunc-len-f 80 p-trunc-len-r 100
but i get again the error message.
why should i have this type of problem if my reads are of good quality ?
i don’t get this.
thank you !