.\" DO NOT MODIFY THIS FILE!  It was generated by help2man 1.48.4.
.TH CD-HIT-EST "1" "August 2021" "cd-hit-est 4.8.1" "User Commands"
.SH NAME
cd-hit-est \- run CD-HIT algorithm on RNA/DNA sequences
.SH SYNOPSIS
.B cd-hit-est
[\fI\,Options\/\fR]
.SH DESCRIPTION
.IP
====== CD\-HIT version 4.8.1 (built on Aug 20 2021) ======
.PP
Options
.TP
\fB\-i\fR
input filename in fasta format, required, can be in .gz format
.TP
\fB\-j\fR
input filename in fasta/fastq format for R2 reads if input are paired end (PE) files
.HP
\fB\-i\fR R1.fq \fB\-j\fR R2.fq \fB\-o\fR output_R1 \fB\-op\fR output_R2 or
.HP
\fB\-i\fR R1.fa \fB\-j\fR R2.fa \fB\-o\fR output_R1 \fB\-op\fR output_R2
.TP
\fB\-o\fR
output filename, required
.TP
\fB\-op\fR
output filename for R2 reads if input are paired end (PE) files
.TP
\fB\-c\fR
sequence identity threshold, default 0.9
this is the default cd\-hit's "global sequence identity" calculated as:
number of identical amino acids or bases in alignment
divided by the full length of the shorter sequence
.TP
\fB\-G\fR
use global sequence identity, default 1
if set to 0, then use local sequence identity, calculated as :
number of identical amino acids or bases in alignment
divided by the length of the alignment
NOTE!!! don't use \fB\-G\fR 0 unless you use alignment coverage controls
see options \fB\-aL\fR, \fB\-AL\fR, \fB\-aS\fR, \fB\-AS\fR
.TP
\fB\-b\fR
band_width of alignment, default 20
.TP
\fB\-M\fR
memory limit (in MB) for the program, default 800; 0 for unlimitted;
.TP
\fB\-T\fR
number of threads, default 1; with 0, all CPUs will be used
.TP
\fB\-n\fR
word_length, default 10, see user's guide for choosing it
.TP
\fB\-l\fR
length of throw_away_sequences, default 10
.TP
\fB\-d\fR
length of description in .clstr file, default 20
if set to 0, it takes the fasta defline and stops at first space
.TP
\fB\-s\fR
length difference cutoff, default 0.0
if set to 0.9, the shorter sequences need to be
at least 90% length of the representative of the cluster
.TP
\fB\-S\fR
length difference cutoff in amino acid, default 999999
if set to 60, the length difference between the shorter sequences
and the representative of the cluster can not be bigger than 60
.TP
\fB\-aL\fR
alignment coverage for the longer sequence, default 0.0
if set to 0.9, the alignment must covers 90% of the sequence
.TP
\fB\-AL\fR
alignment coverage control for the longer sequence, default 99999999
if set to 60, and the length of the sequence is 400,
then the alignment must be >= 340 (400\-60) residues
.TP
\fB\-aS\fR
alignment coverage for the shorter sequence, default 0.0
if set to 0.9, the alignment must covers 90% of the sequence
.TP
\fB\-AS\fR
alignment coverage control for the shorter sequence, default 99999999
if set to 60, and the length of the sequence is 400,
then the alignment must be >= 340 (400\-60) residues
.TP
\fB\-A\fR
minimal alignment coverage control for the both sequences, default 0
alignment must cover >= this value for both sequences
.TP
\fB\-uL\fR
maximum unmatched percentage for the longer sequence, default 1.0
if set to 0.1, the unmatched region (excluding leading and tailing gaps)
must not be more than 10% of the sequence
.TP
\fB\-uS\fR
maximum unmatched percentage for the shorter sequence, default 1.0
if set to 0.1, the unmatched region (excluding leading and tailing gaps)
must not be more than 10% of the sequence
.TP
\fB\-U\fR
maximum unmatched length, default 99999999
if set to 10, the unmatched region (excluding leading and tailing gaps)
must not be more than 10 bases
.TP
\fB\-B\fR
1 or 0, default 0, by default, sequences are stored in RAM
if set to 1, sequence are stored on hard drive
!! No longer supported !!
.TP
\fB\-P\fR
input paired end (PE) reads, default 0, single file
if set to 1, please use \fB\-i\fR R1 \fB\-j\fR R2 to input both PE files
.TP
\fB\-cx\fR
length to keep after trimming the tail of sequence, default 0, not trimming
if set to 50, the program only uses the first 50 letters of input sequence
.TP
\fB\-cy\fR
length to keep after trimming the tail of R2 sequence, default 0, not trimming
if set to 50, the program only uses the first 50 letters of input R2 sequence
e.g. \fB\-cx\fR 100 \fB\-cy\fR 80 for paired end reads
.TP
\fB\-ap\fR
alignment position constrains,  default 0, no constrain
if set to 1, the program will force sequences to align at beginings
when set to 1, the program only does +/+ alignment
.TP
\fB\-p\fR
1 or 0, default 0
if set to 1, print alignment overlap in .clstr file
.TP
\fB\-g\fR
1 or 0, default 0
by cd\-hit's default algorithm, a sequence is clustered to the first
cluster that meet the threshold (fast cluster). If set to 1, the program
will cluster it into the most similar cluster that meet the threshold
(accurate but slow mode)
but either 1 or 0 won't change the representatives of final clusters
.TP
\fB\-r\fR
1 or 0, default 1, by default do both +/+ & +/\- alignments
if set to 0, only +/+ strand alignment
.TP
\fB\-mask\fR
masking letters (e.g. \fB\-mask\fR NX, to mask out both 'N' and 'X')
.TP
\fB\-match\fR
matching score, default 2 (1 for T\-U and N\-N)
.TP
\fB\-mismatch\fR
mismatching score, default \fB\-2\fR
.HP
\fB\-gap\fR gap opening score, default \fB\-6\fR
.TP
\fB\-gap\-ext\fR
gap extension score, default \fB\-1\fR
.HP
\fB\-bak\fR write backup cluster file (1 or 0, default 0)
.TP
\fB\-sc\fR
sort clusters by size (number of sequences), default 0, output clusters by decreasing length
if set to 1, output clusters by decreasing size
.TP
\fB\-sf\fR
sort fasta/fastq by cluster size (number of sequences), default 0, no sorting
if set to 1, output sequences by decreasing cluster size
this can be very slow if the input is in .gz format
.TP
\fB\-h\fR
print this help
.IP
Questions, bugs, contact Weizhong Li at liwz@sdsc.edu
For updated versions and information, please visit: http://cd\-hit.org
.IP
or https://github.com/weizhongli/cdhit
.IP
cd\-hit web server is also available from http://cd\-hit.org
.IP
If you find cd\-hit useful, please kindly cite:
.IP
"CD\-HIT: a fast program for clustering and comparing large sets of protein or nucleotide sequences", Weizhong Li & Adam Godzik. Bioinformatics, (2006) 22:1658\-1659
"CD\-HIT: accelerated for clustering the next generation sequencing data", Limin Fu, Beifang Niu, Zhengwei Zhu, Sitao Wu & Weizhong Li. Bioinformatics, (2012) 28:3150\-3152