porechop - adapter trimmer for Oxford Nanopore reads
porechop [-h] -i INPUT [-o OUTPUT] [--format
{auto,fasta,fastq,fasta.gz,fastq.gz}] [-v VERBOSITY] [-t THREADS]
[--version] [-b BARCODE_DIR] [--barcode_threshold BARCODE_THRESHOLD]
[--barcode_diff BARCODE_DIFF] [--require_two_barcodes] [--untrimmed]
[--discard_unassigned] [--adapter_threshold ADAPTER_THRESHOLD]
[--check_reads CHECK_READS] [--scoring_scheme SCORING_SCHEME] [--end_size
END_SIZE] [--min_trim_size MIN_TRIM_SIZE] [--extra_end_trim EXTRA_END_TRIM]
[--end_threshold END_THRESHOLD] [--no_split] [--discard_middle]
[--middle_threshold MIDDLE_THRESHOLD] [--extra_middle_trim_good_side
EXTRA_MIDDLE_TRIM_GOOD_SIDE] [--extra_middle_trim_bad_side
EXTRA_MIDDLE_TRIM_BAD_SIDE] [--min_split_read_size MIN_SPLIT_READ_SIZE]
Porechop: a tool for finding adapters in Oxford Nanopore reads,
trimming them from the ends and splitting reads with internal adapters
- -i INPUT, --input
INPUT
- FASTA/FASTQ of input reads or a directory which will be recursively
searched for FASTQ files (required)
- -o OUTPUT, --output
OUTPUT
- Filename for FASTA or FASTQ of trimmed reads (if not set, trimmed reads
will be printed to stdout)
- --format
{auto,fasta,fastq,fasta.gz,fastq.gz}
- Output format for the reads - if auto, the format will be chosen based on
the output filename or the input read format (default: auto)
- -v VERBOSITY,
--verbosity VERBOSITY
- Level of progress information: 0 = none, 1 = some, 2 = lots, 3 = full -
output will go to stdout if reads are saved to a file and stderr if reads
are printed to stdout (default: 1)
- -t THREADS, --threads
THREADS
- Number of threads to use for adapter alignment (default: 4)
- --version
- show program's version number and exit
- Control the binning of reads based on barcodes (i.e. barcode
demultiplexing)
- -b BARCODE_DIR,
--barcode_dir BARCODE_DIR
- Reads will be binned based on their barcode and saved to separate files in
this directory (incompatible with --output)
- --barcode_threshold
BARCODE_THRESHOLD
- A read must have at least this percent identity to a barcode to be binned
(default: 75.0)
- --barcode_diff
BARCODE_DIFF
- If the difference between a read's best barcode identity and its
second-best barcode identity is less than this value, it will not be put
in a barcode bin (to exclude cases which are too close to call) (default:
5.0)
- --require_two_barcodes
- Reads will only be put in barcode bins if they have a strong match for the
barcode on both their start and end (default: a read can be binned with a
match at its start or end)
- --untrimmed
- Bin reads but do not trim them (appropriate if reads are to be used with
Nanopolish) (default: trim the reads)
- --discard_unassigned
- Discard unassigned reads (instead of creating a "none" bin)
(default: False)
- Control how the program determines which adapter sets are present
- --adapter_threshold
ADAPTER_THRESHOLD
- An adapter set has to have at least this percent identity to be labelled
as present and trimmed off (0 to 100) (default: 90.0)
- --check_reads
CHECK_READS
- This many reads will be aligned to all possible adapters to determine
which adapter sets are present (default: 10000)
- --scoring_scheme
SCORING_SCHEME
- Comma-delimited string of alignment scores: match, mismatch, gap open, gap
extend (default: 3,-6,-5,-2)
- Control the trimming of adapters from read ends
- --end_size
END_SIZE
- The number of base pairs at each end of the read which will be searched
for adapter sequences (default: 150)
- --min_trim_size
MIN_TRIM_SIZE
- Adapter alignments smaller than this will be ignored (default: 4)
- This many additional bases will be removed next to adapters found at the
ends of reads (default: 2)
- --end_threshold
END_THRESHOLD
- Adapters at the ends of reads must have at least this percent identity to
be removed (0 to 100) (default: 75.0)
- Control the splitting of read from middle adapters
- --no_split
- Skip splitting reads based on middle adapters (default: split reads when
an adapter is found in the middle)
- --discard_middle
- Reads with middle adapters will be discarded (default: reads with middle
adapters are split) (this option is on by default when outputting reads
into barcode bins)
- --middle_threshold
MIDDLE_THRESHOLD
- Adapters in the middle of reads must have at least this percent identity
to be found (0 to 100) (default: 85.0)
- This many additional bases will be removed next to middle adapters on
their "good" side (default: 10)
- This many additional bases will be removed next to middle adapters on
their "bad" side (default: 100)
- --min_split_read_size
MIN_SPLIT_READ_SIZE
- Post-split read pieces smaller than this many base pairs will not be
outputted (default: 1000)
This manpage was written by Andreas Tille for the Debian
distribution and can be used for any other usage of the program.