fastq-mcf1

Ea-utils: detect levels of adapter presence, compute likelihoods and locations of the adapters

Usage

fastq-mcf [options] <adapters.fa> <reads.fq> [mates1.fq ...]

Overview

Version: 1.04.676

Detects levels of adapter presence, computes likelihoods and locations (start, end) of the adapters. Removes the adapter sequences from the fastq file(s).

Stats go to stderr, unless -o is specified.

Specify -0 to turn off all default settings

If you specify multiple 'paired-end' inputs, then a -o option is required for each. IE: -o read1.clip.q -o read2.clip.fq

Options

-h: This help

-o FIL: Output file (stats to stdout)

-s N.N: Log scale for adapter minimum-length-match (2.2)

-t N: % occurance threshold before adapter clipping (0.25)

-m N: Minimum clip length, overrides scaled auto (1)

-p N: Maximum adapter difference percentage (10)

-l N: Minimum remaining sequence length (19)

-L N: Maximum remaining sequence length (none)

-D N: Remove duplicate reads : Read_1 has an identical N bases (0)

-k N: sKew percentage-less-than causing cycle removal (2)

-x N: 'N' (Bad read) percentage causing cycle removal (20)

-q N: quality threshold causing base removal (10)

-w N: window-size for quality trimming (1)

-H: remove >95% homopolymer reads (no)

-X: remove low complexity reads (no)

-0: Set all default parameters to zero/do nothing

-U|u: Force disable/enable Illumina PF filtering (auto)

-P N: Phred-scale (auto)

-R: Don't remove N's from the fronts/ends of reads

-n: Don't clip, just output what would be done

-C N: Number of reads to use for subsampling (300k)

-S: Save all discarded reads to '.skip' files

-d: Output lots of random debugging stuff

Quality adjustment options:

--cycle-adjust: CYC,AMT Adjust cycle CYC (negative = offset from end) by amount AMT

--phred-adjust: SCORE,AMT Adjust score SCORE by amount AMT

--phred-adjust-max: SCORE Adjust scores > SCORE to SCOTE

Filtering options*:

`--[mate-]qual-mean`	NUM Minimum mean quality score
`--[mate-]qual-gt`	NUM,THR At least NUM quals > THR
`--[mate-]max-ns`	NUM Maxmium N-calls in a read (can be a %)
`--[mate-]min-len`	NUM Minimum remaining length (same as `-l`)

--homopolymer-pct: PCT Homopolymer filter percent (95)

--lowcomplex-pct: PCT Complexity filter percent (95)

If mate- prefix is used, then applies to second non-barcode read only

Adapter files are 'fasta' formatted:

Specify n/a to turn off adapter clipping, and just use filters

Increasing the scale makes recognition-lengths longer, a scale of 100 will force full-length recognition of adapters.

Adapter sequences with _5p in their label will match 'end's, and sequences with _3p in their label will match 'start's, otherwise the 'end' is auto-determined.

Skew is when one cycle is poor, 'skewed' toward a particular base. If any nucleotide is less than the skew percentage, then the whole cycle is removed. Disable for methyl-seq, etc.

Set the skew (-k) or N-pct (-x) to 0 to turn it off (should be done for miRNA, amplicon and other low-complexity situations!)

Duplicate read filtering is appropriate for assembly tasks, and never when read length < expected coverage. -D 50 will use 4.5GB RAM on 100m DNA reads - be careful. Great for RNA assembly.

*Quality filters are evaluated after clipping/trimming

Homopolymer filtering is a subset of low-complexity, but will not be separately tracked unless both are turned on.

Releases

Unchanged in 5 releases since Debian 9 (Stretch).

9–13