Provided by: bbmap_38.79+dfsg-1_all bug

NAME

       bbduk.sh  -  Filters,  trims,  or masks reads with kmer matches to an artifact/contaminant
       file

SYNOPSIS

       bbduk.sh in=<input file> out=<output file> ref=<contaminant files>

DESCRIPTION

       Compares reads to the kmers in a reference dataset, optionally allowing an edit  distance.
       Splits  the reads into two outputs - those that match the reference, and those that don't.
       Can also trim (remove) the matching parts of the reads  rather  than  binning  the  reads.
       Please read bbmap/docs/guides/BBDukGuide.txt for more information.

       Input  may be stdin or a fasta or fastq file, compressed or uncompressed.  If you pipe via
       stdin/stdout,  please  include  the  file  type;  e.g.  for  gzipped  fasta   input,   set
       in=stdin.fa.gz

OPTIONS

   Input parameters
       in=<file>
              Main input. in=stdin.fq will pipe from stdin.

       in2=<file>
              Input for 2nd read of pairs in a different file.

       ref=<file,file>
              Comma-delimited list of reference files.

              In addition to filenames, you may also use the keywords: adapters, artifacts, phix,
              lambda, pjet, mtst, kapa

       literal=<seq,seq>
              Comma-delimited list of literal reference sequences.

       touppercase=f
              (tuc) Change all bases upper-case.

       interleaved=auto
              (int) t/f overrides interleaved autodetection.

       qin=auto
              Input quality offset: 33 (Sanger), 64, or auto.

       reads=-1
              If positive, quit after processing X reads or pairs.

       copyundefined=f
              (cu) Process non-AGCT IUPAC reference bases  by  making  all  possible  unambiguous
              copies.   Intended  for  short  motifs  or  adapter barcodes, as time/memory use is
              exponential.

       samplerate=1
              Set lower to only process a fraction of input reads.

       samref=<file>
              Optional reference fasta for processing sam files.

   Output parameters
       out=<file>
              (outnonmatch) Write reads here that do not contain  kmers  matching  the  database.
              'out=stdout.fq' will pipe to standard out.

       out2=<file>
              (outnonmatch2) Use this to write 2nd read of pairs to a different file.

       outm=<file>
              (outmatch) Write reads here that fail filters.  In default kfilter mode, this means
              any read with a matching kmer.  In any mode,  it  also  includes  reads  that  fail
              filters such as minlength, mingc, maxgc, entropy, etc.  In other words, it includes
              all reads that do not go to 'out'.

       outm2=<file>
              (outmatch2) Use this to write 2nd read of pairs to a different file.

       outs=<file>
              (outsingle) Use this to write singleton reads whose mate was trimmed  shorter  than
              minlen.

       stats=<file>
              Write statistics about which contamininants were detected.

       refstats=<file>
              Write statistics on a per-reference-file basis.

       rpkm=<file>
              Write RPKM for each reference sequence (for RNA-seq).

       dump=<file>
              Dump kmer tables to a file, in fasta format.

       duk=<file>
              Write statistics in duk's format. *DEPRECATED*

       nzo=t  Only write statistics about ref sequences with nonzero hits.

       overwrite=t
              (ow) Grant permission to overwrite files.

       showspeed=t
              (ss) 'f' suppresses display of processing speed.

       ziplevel=2
              (zl) Compression level; 1 (min) through 9 (max).

       fastawrap=70
              Length of lines in fasta output.

       qout=auto
              Output quality offset: 33 (Sanger), 64, or auto.

       statscolumns=3
              cols) Number of columns for stats output, 3 or 5.  5 includes base counts.

       rename=f
              Rename reads to indicate which sequences they matched.

       refnames=f
              Use names of reference files rather than scaffold IDs.

       trd=f  Truncate read and ref names at the first whitespace.

       ordered=f
              Set to true to output reads in same order as input.

       maxbasesout=-1
              If   positive,   quit   after   writing   approximately  this  many  bases  to  out
              (outu/outnonmatch).

       maxbasesoutm=-1
              If positive, quit after writing approximately this many bases to outm (outmatch).

       json=f Print to screen in json format.

   Histogram output parameters
       bhist=<file>
              Base composition histogram by position.

       qhist=<file>
              Quality histogram by position.

       qchist=<file>
              Count of bases with each quality value.

       aqhist=<file>
              Histogram of average read quality.

       bqhist=<file>
              Quality histogram designed for box plots.

       lhist=<file>
              Read length histogram.

       phist=<file>
              Polymer length histogram.

       gchist=<file>
              Read GC content histogram.

       ihist=<file>
              Insert size histogram, for paired reads in mapped sam.

       gcbins=100
              Number gchist bins.  Set to 'auto' to use read length.

       maxhistlen=6000
              Set an upper bound for histogram lengths; higher uses more memory.  The default  is
              6000 for some histograms and 80000 for others.

   Histograms for mapped sam/bam files only
       histbefore=t
              Calculate histograms from reads before processing.

       ehist=<file>
              Errors-per-read histogram.

       qahist=<file>
              Quality accuracy histogram of error rates versus quality score.

       indelhist=<file>
              Indel length histogram.

       mhist=<file>
              Histogram of match, sub, del, and ins rates by position.

       idhist=<file>
              Histogram of read count versus percent identity.

       idbins=100
              Number idhist bins.  Set to 'auto' to use read length.

       varfile=<file>
              Ignore  substitution  errors listed in this file when calculating error rates.  Can
              be generated with CallVariants.

       vcf=<file>
              Ignore substitution errors listed in this VCF file when calculating error rates.

       ignorevcfindels=t
              Also ignore indels listed in the VCF.

   Processing parameters
       k=27   Kmer length used for finding contaminants.  Contaminants shorter than k will not be
              found.  k must be at least 1.

       rcomp=t
              Look for reverse-complements of kmers in addition to forward kmers.

       maskmiddle=t
              (mm)  Treat the middle base of a kmer as a wildcard, to increase sensitivity in the
              presence of errors.

       minkmerhits=1
              (mkh) Reads need at least this many matching kmers to be considered as matching the
              reference.

       minkmerfraction=0.0
              (mkf)  A  reads  needs  at  least this fraction of its total kmers to hit a ref, in
              order to be considered a match.  If this and minkmerhits are set,  the  greater  is
              used.

       mincovfraction=0.0
              (mcf)  A reads needs at least this fraction of its total bases to be covered by ref
              kmers to be considered a match.  If specified, mcf overrides mkh and mkf.

       hammingdistance=0
              (hdist) Maximum Hamming  distance  for  ref  kmers  (subs  only).   Memory  use  is
              proportional to (3*K)^hdist.

       qhdist=0
              Hamming distance for query kmers; impacts speed, not memory.

       editdistance=0
              (edist) Maximum edit distance from ref kmers (subs and indels).

              Memory use is proportional to (8*K)^edist.

       hammingdistance2=0
              (hdist2) Sets hdist for short kmers, when using mink.

       qhdist2=0
              Sets qhdist for short kmers, when using mink.

       editdistance2=0
              (edist2) Sets edist for short kmers, when using mink.

       forbidn=f
              (fn) Forbids matching of read kmers containing N.

              By  default,  these  will  match a reference 'A' if hdist>0 or edist>0, to increase
              sensitivity.

       removeifeitherbad=t
              (rieb) Paired reads get sent to 'outmatch' if either is match (or either is trimmed
              shorter than minlen).  Set to false to require both.

       trimfailures=f
              Instead of discarding failed reads, trim them to 1bp.

              This makes the statistics a bit odd.

       findbestmatch=f
              (fbm)  If  multiple  matches,  associate  read  with  sequence  sharing most kmers.
              Reduces speed.

       skipr1=f
              Don't do kmer-based operations on read 1.

       skipr2=f
              Don't do kmer-based operations on read 2.

       ecco=f For overlapping paired reads only.  Performs errorcorrection with BBMerge prior  to
              kmer operations.

       recalibrate=f
              (recal)  Recalibrate  quality  scores.   Requires calibration matrices generated by
              CalcTrueQuality.

       sam=<file,file>
              If recalibration is desired, and matrices have not already  been  generated,  BBDuk
              will create them from the sam file.

       amino=f
              Run  in  amino  acid  mode.   Some features have not been tested, but kmer-matching
              works fine.  Maximum k is 12.

   Speed and Memory parameters
       threads=auto
              (t) Set number of threads to use; default is number of logical processors.

       prealloc=f
              Preallocate memory in table.  Allows faster table loading and more efficient memory
              usage, for a large reference.

       monitor=f
              Kill  this  process  if  it crashes.  monitor=600,0.01 would kill after 600 seconds
              under 1% usage.

       minrskip=1
              (mns) Force minimal skip interval when indexing reference kmers.

              1 means use all, 2 means use every other kmer, etc.

       maxrskip=1
              (mxs) Restrict maximal skip interval when indexing reference  kmers.  Normally  all
              are  used  for  scaffolds<100kb,  but  with  longer scaffolds, up to maxrskip-1 are
              skipped.

       rskip= Set both minrskip and maxrskip to the same value.

              If not set, rskip will vary based on sequence length.

       qskip=1
              Skip query kmers to increase speed.  1 means use all.

       speed=0
              Ignore this fraction of kmer space (0-15 out of 16) in both  reads  and  reference.
              Increases speed and reduces memory.

              Note: Do not use more than one of 'speed', 'qskip', and 'rskip'.

   Trimming/Filtering/Masking parameters
       Note  -  if ktrim, kmask, and ksplit are unset, the default behavior is kfilter.  All kmer
       processing modes are mutually exclusive.  Reads only get sent to 'outm'  purely  based  on
       kmer matches in kfilter mode.

       ktrim=f
              Trim reads to remove bases matching reference kmers.

              Values:

              f (don't trim),

              r (trim to the right),

              l (trim to the left)

       kmask= Replace bases matching ref kmers with another symbol.

       Allows any non-whitespace character, and processes short
              kmers  on  both  ends  if  mink  is  set.   'kmask=lc' will convert masked bases to
              lowercase.

       maskfullycovered=f  (mfc) Only mask bases that  are  fully  covered  by  kmers.   ksplit=f
       For single-ended reads only.  Reads will be split into

       pairs around the kmer.
              If the kmer is at the end of the

       read, it will be trimmed instead.
              Singletons will go to

       out, and pairs will go to outm.
              Do not use ksplit with

              other operations such as quality-trimming or filtering.

       mink=0              Look for shorter kmers at read tips down to this length,

       when k-trimming or masking.
              0 means disabled.  Enabling

              this will disable maskmiddle.

       qtrim=f             Trim read ends to remove bases with quality below trimq.

       Performed AFTER looking for kmers.
              Values:

       rl (trim both ends),
              f (neither end), r (right end only), l (left end only), w (sliding window).

       trimq=6
              Regions  with  average  quality  BELOW  this  will  be  trimmed, if qtrim is set to
              something other than f.  Can be a floating-point number like 7.3.

       trimclip=f
              Trim soft-clipped bases from sam files.

       minlength=10
              (ml) Reads shorter than this after trimming  will  be  discarded.   Pairs  will  be
              discarded if both are shorter.

       mlf=0  (minlengthfraction)  Reads  shorter  than  this  fraction  of original length after
              trimming will be discarded.

       maxlength=
              Reads longer than this after trimming will be discarded.  Pairs will  be  discarded
              only if both are longer.

       minavgquality=0
              (maq) Reads with average quality (after trimming) below this will be discarded.

       maqb=0 If positive, calculate maq from this many initial bases.

       minbasequality=0
              (mbq) Reads with any base below this quality (after trimming) will be discarded.

       maxns=-1
              If non-negative, reads with more Ns than this (after trimming) will be discarded.

       mcb=0  (minconsecutivebases)  Discard  reads without at least this many consecutive called
              bases.

       ottm=f (outputtrimmedtomatch) Output reads trimmed  to  shorter  than  minlength  to  outm
              rather than discarding.

       tp=0   (trimpad) Trim this much extra around matching kmers.

       tbo=f  (trimbyoverlap) Trim adapters based on where paired reads overlap.

       strictoverlap=t
              Adjust sensitivity for trimbyoverlap mode.

       minoverlap=14
              Require this many bases of overlap for detection.

       mininsert=40
              Require  insert  size  of  at  least this for overlap.  Should be reduced to 16 for
              small RNA sequencing.

       tpe=f  (trimpairsevenly) When kmer right-trimming, trim both reads to the  minimum  length
              of either.

       forcetrimleft=0
              (ftl) If positive, trim bases to the left of this position (exclusive, 0-based).

       forcetrimright=0
              (ftr) If positive, trim bases to the right of this position (exclusive, 0-based).

       forcetrimright2=0
              (ftr2) If positive, trim this many bases on the right end.

       forcetrimmod=0
              (ftm) If positive, right-trim length to be equal to zero, modulo this number.

       restrictleft=0
              If positive, only look for kmer matches in the leftmost X bases.

       restrictright=0
              If positive, only look for kmer matches in the rightmost X bases.

       mingc=0
              Discard reads with GC content below this.

       maxgc=1
              Discard reads with GC content above this.

       gcpairs=t
              Use average GC of paired reads.  Also affects gchist.

       tossjunk=f
              Discard reads with invalid characters as bases.

       swift=f
              Trim Swift sequences: Trailing C/T/N R1, leading G/A/N R2.

   Header-parsing parameters - these require Illumina headers
       chastityfilter=f
              (cf) Discard reads with id containing ' 1:Y:' or ' 2:Y:'.

       barcodefilter=f
              Remove reads with unexpected barcodes if barcodes is set,

              or  barcodes containing 'N' otherwise.  A barcode must be the last part of the read
              header.

              Values:

              t: Remove reads with bad barcodes.

              f: Ignore barcodes.

              crash: Crash upon encountering bad barcodes.

       barcodes=
              Comma-delimited list of barcodes or files of barcodes.

       xmin=-1
              If positive, discard reads with a lesser X coordinate.

       ymin=-1
              If positive, discard reads with a lesser Y coordinate.

       xmax=-1
              If positive, discard reads with a greater X coordinate.

       ymax=-1
              If positive, discard reads with a greater Y coordinate.

   Polymer trimming
       trimpolya=0
              If greater than 0, trim poly-A or poly-T tails of at least this  length  on  either
              end of reads.

       trimpolygleft=0
              If  greater than 0, trim poly-G prefixes of at least this length on the left end of
              reads.  Does not trim poly-C.

       trimpolygright=0
              If greater than 0, trim poly-G tails of at least this length on the  right  end  of
              reads.  Does not trim poly-C.

       trimpolyg=0
              This sets both left and right at once.

       filterpolyg=0
              If  greater  than  0, remove reads with a poly-G prefix of at least this length (on
              the left).

              Note: there are also equivalent poly-C flags.

   Polymer tracking
       pratio=base,base

       plen=20
              Length of homopolymers to count.

   Entropy/Complexity parameters
       entropy=-1
              Set between 0 and 1 to filter reads with entropy below that value.  Higher is  more
              stringent.

       entropywindow=50
              Calculate entropy using a sliding window of this length.

       entropyk=5
              Calculate entropy using kmers of this length.

       minbasefrequency=0
              Discard reads with a minimum base frequency below this.

       entropymask=f
              Values:

              f: Discard low-entropy sequences.

              t: Mask low-entropy parts of sequences with N.

              lc: Change low-entropy parts of sequences to lowercase.

       entropymark=f
              Mark  each base with its entropy value.  This is on a scale of 0-41 and is reported
              as quality scores, so the output should be fastq or fasta+qual.

   Cardinality estimation
       cardinality=f
              (loglog) Count unique kmers using the LogLog algorithm.

       cardinalityout=f
              (loglogout) Count unique kmers in output reads.

       loglogk=31
              Use this kmer length for counting.

       loglogbuckets=1999
              Use this many buckets for counting.

   Java Parameters
       -Xmx   This will set Java's memory usage, overriding autodetection.

              -Xmx20g will specify 20 gigs of RAM, and -Xmx200m will specify 200 megs.   The  max
              is typically 85% of physical memory.

       -eoom  This  flag  will  cause  the  process to exit if an out-of-memory exception occurs.
              Requires Java 8u92+.

       -da    Disable assertions.

AUTHOR

       Written by Brian Bushnell, Last modified March 21, 2019

       Please contact Brian Bushnell at bbushnell@lbl.gov if you encounter any problems.

       This manpage was written by Andreas Tille for the Debian distribution and can be used  for
       any other usage of the program.