/ 
Proch-N50-0.08
River stage zero No dependents
/ Proch::N50

NAME

Proch::N50 - a small module to calculate N50 (total size, and total number of sequences) for a FASTA or FASTQ file. It's small and without dependencies.

VERSION

version 0.08

SYNOPSIS

use Proch::N50 qw(getStats getN50);
my $filepath = '/path/to/assembly.fasta';

# Get N50 only: getN50(file) will return an integer
print "N50 only:\t", getN50($filepath), "\n";

# Full stats
my $seq_stats = getStats($filepath);
print Data::Dumper->Dump( [ $seq_stats ], [ qw(*FASTA_stats) ] );
# Will print:
# %FASTA_stats = (
#               'N50' => 65,
#               'min' => 4,
#               'max' => 65,
#               'dirname' => 'data',
#               'size' => 130,
#               'seqs' => 6,
#               'filename' => 'small_test.fa',
#               'status' => 1
#             );

# Get also a JSON object
my $seq_stats_with_JSON = getStats($filepath, 'JSON');
print $seq_stats_with_JSON->{json}, "\n";
# Will print:
# {
#    "status" : 1,
#    "seqs" : 6,
#    <...>
#    "filename" : "small_test.fa",
#    "N50" : "65",
# }

METHODS

getN50(filepath)

This function returns the N50 for a FASTA/FASTQ file given, or 0 in case of error(s).

getStats(filepath, alsoJSON)

Calculates N50 and basic stats for <filepath>. Returns also JSON if invoked with a second parameter. This function return a hash reporting:

size (int)

total number of bp in the files

N50 (int)

the actual N50

min (int)

Minimum length observed in FASTA/Q file

max (int)

Maximum length observed in FASTA/Q file

seqs (int)

total number of sequences in the files

filename (string)

file basename of the input file

dirname (string)

name of the directory containing the input file

json (string: JSON pretty printed)

(pretty printed) JSON string of the object (only if JSON is installed)

jsonStats(filepath)

Returns the JSON string with basic stats (same as $result->{json} from getStats(File, JSON)). Requires JSON::PP installed.

_n50fromHash(hash, totalsize)

This is an internal helper subroutine that perform the actual N50 calculation, hence its addition to the documentation. Expects the reference to an hash of sizes $size{SIZE} = COUNT and the total sum of sizes obtained parsing the sequences file. Returns N50, min and max lengths.

Dependencies

JSON::PP (core)
Term::ANSIColor (optional) for the n50.pl script

AUTHOR

Andrea Telatin <andrea.telatin@quadram.ac.uk>

COPYRIGHT AND LICENSE

This software is Copyright (c) 2019 by Andrea Telatin.

This is free software, licensed under:

The MIT (X11) License