porechop1
Adapter trimmer for oxford nanopore reads
Usage
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]
Overview
Porechop: a tool for finding adapters in Oxford Nanopore reads, trimming them from the ends and splitting reads with internal adapters
Options
optional arguments:
-
-h, --help -
show this help message and exit
Main options:
-
-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
Barcode binning settings:
-
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)
Adapter search settings:
-
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)
End adapter settings:
-
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)
-
--extra_end_trim EXTRA_END_TRIM -
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)
Middle adapter settings:
-
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)
-
--extra_middle_trim_good_side EXTRA_MIDDLE_TRIM_GOOD_SIDE -
This many additional bases will be removed next to middle adapters on their "good" side (default: 10)
-
--extra_middle_trim_bad_side EXTRA_MIDDLE_TRIM_BAD_SIDE -
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)
Releases
Unchanged in 4 releases since Debian 10 (Buster).