.\" DO NOT MODIFY THIS FILE! It was generated by help2man 1.49.3. .TH IVA "1" "February 2024" "iva 1.0.8" "User Commands" .SH NAME iva \- iterative virus assembler .SH DESCRIPTION usage: iva [options] {\-f reads_fwd \fB\-r\fR reads_rev | \fB\-\-fr\fR reads} .SS "positional arguments:" .TP Output directory Name of output directory (must not already exist) .SS "options:" .TP \fB\-h\fR, \fB\-\-help\fR show this help message and exit .SS "Input and output:" .TP \fB\-f\fR filename[.gz], \fB\-\-reads_fwd\fR filename[.gz] Name of forward reads fasta/q file. Must be used in conjunction with \fB\-\-reads_rev\fR .TP \fB\-r\fR filename[.gz], \fB\-\-reads_rev\fR filename[.gz] Name of reverse reads fasta/q file. Must be used in conjunction with \fB\-\-reads_fwd\fR .TP \fB\-\-fr\fR filename[.gz] Name of interleaved fasta/q file .TP \fB\-\-keep_files\fR Keep intermediate files (could be many!). Default is to delete all unnecessary files .TP \fB\-\-contigs\fR filename[.gz] Fasta file of contigs to be extended. Incompatible with \fB\-\-reference\fR .TP \fB\-\-reference\fR filename[.gz] EXPERIMENTAL! This option is EXPERIMENTAL, not recommended, and has not been tested! Fasta file of reference genome, or parts thereof. IVA will try to assemble one contig per sequence in this file. Incompatible with \fB\-\-contigs\fR .TP \fB\-v\fR, \fB\-\-verbose\fR Be verbose by printing messages to stdout. Use up to three times for increasing verbosity. .SS "SMALT mapping options:" .TP \fB\-k\fR INT, \fB\-\-smalt_k\fR INT kmer hash length in SMALT (the \fB\-k\fR option in smalt index) [19] .TP \fB\-s\fR INT, \fB\-\-smalt_s\fR INT kmer hash step size in SMALT (the \fB\-s\fR option in smalt index) [11] .TP \fB\-y\fR FLOAT, \fB\-\-smalt_id\fR FLOAT Minimum identity threshold for mapping to be reported (the \fB\-y\fR option in smalt map) [0.5] .SS "Contig options:" .TP \fB\-\-ctg_first_trim\fR INT Number of bases to trim off the end of every contig before extending for the first time [25] .TP \fB\-\-ctg_iter_trim\fR INT During iterative extension, number of bases to trim off the end of a contig when extension fails (then try extending again) [10] .TP \fB\-\-ext_min_cov\fR INT Minimum kmer depth needed to use that kmer to extend a contig [10] .TP \fB\-\-ext_min_ratio\fR FLOAT Sets N, where kmer for extension must be at least N times more abundant than next most common kmer [4] .TP \fB\-\-ext_max_bases\fR INT Maximum number of bases to try to extend on each iteration [100] .TP \fB\-\-ext_min_clip\fR INT Set minimum number of bases soft clipped off a read for those bases to be used for extension [3] .TP \fB\-\-max_contigs\fR INT Maximum number of contigs allowed in the assembly. No more seeds generated if the cutoff is reached [50] .SS "Seed generation options:" .TP \fB\-\-make_new_seeds\fR When no more contigs can be extended, generate a new seed. This is forced to be true when \fB\-\-contigs\fR is not used .TP \fB\-\-seed_start_length\fR INT When making a seed sequence, use the most common kmer of this length. Default is to use the minimum of (median read length, 95). Warning: it is not recommended to set this higher than 95 .TP \fB\-\-seed_stop_length\fR INT Stop extending seed using perfect matches from reads when this length is reached. Future extensions are then made by treating the seed as a contig [0.9*max_insert] .TP \fB\-\-seed_min_kmer_cov\fR INT Minimum kmer coverage of initial seed [25] .TP \fB\-\-seed_max_kmer_cov\fR INT Maximum kmer coverage of initial seed [1000000] .TP \fB\-\-seed_ext_max_bases\fR INT Maximum number of bases to try to extend on each iteration [50] .TP \fB\-\-seed_overlap_length\fR INT Number of overlapping bases needed between read and seed to use that read to extend [seed_start_length] .TP \fB\-\-seed_ext_min_cov\fR INT Minimum kmer depth needed to use that kmer to extend a contig [10] .TP \fB\-\-seed_ext_min_ratio\fR FLOAT Sets N, where kmer for extension must be at least N times more abundant than next most common kmer [4] .SS "Read trimming options:" .TP \fB\-\-trimmomatic\fR FILENAME Provide location of trimmomatic.jar file to enable read trimming. Required if \fB\-\-adapters\fR used .TP \fB\-\-trimmo_qual\fR STRING Trimmomatic options used to quality trim reads [LEADING:10 TRAILING:10 SLIDINGWINDOW:4:20] .TP \fB\-\-adapters\fR FILENAME Fasta file of adapter sequences to be trimmed off reads. If used, must also use \fB\-\-trimmomatic\fR. Default is file of adapters supplied with IVA .TP \fB\-\-min_trimmed_length\fR INT Minimum length of read after trimming [50] .TP \fB\-\-pcr_primers\fR FILENAME FASTA file of primers. The first perfect match found to a sequence in the primers file will be trimmed off the start of each read. This is run after trimmomatic (if \fB\-\-trimmomatic\fR used) .SS "Other options:" .TP \fB\-i\fR INT, \fB\-\-max_insert\fR INT Maximum insert size (includes read length). Reads with inferred insert size more than the maximum will not be used to extend contigs [800] .TP \fB\-t\fR INT, \fB\-\-threads\fR INT Number of threads to use [1] .TP \fB\-\-kmc_onethread\fR Force kmc to use one thread. By default the value of \fB\-t\fR/\-\-threads is used when running kmc .TP \fB\-\-strand_bias\fR FLOAT in [0,0.5] Set strand bias cutoff of mapped reads when trimming contig ends, in the interval [0,0.5]. A value of x means that a base needs min(fwd_depth, rev_depth) / total_depth <= x. The only time this should be used is with libraries with overlapping reads (ie fragment length < 2*read length), and even then, it can make results worse. If used, try a low value like 0.1 first [0] .TP \fB\-\-test\fR Run using built in test data. All other options will be ignored, except the mandatory output directory, and \fB\-\-trimmomatic\fR and \fB\-\-threads\fR can be also be used .TP \fB\-\-version\fR show program's version number and exit