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#!/usr/bin/env perl
use strict;
use warnings;
use lib ("/usr/lib/trinityrnaseq/PerlLib");
use Fasta_reader;
my $usage = "\n\nusage: $0 transcripts.fasta\n\n";
my $fasta_file = $ARGV[0] or die $usage;
main: {
my $fasta_reader = new Fasta_reader($fasta_file);
my @seq_lengths;
my $cum_seq_len = 0;
while (my $seq_obj = $fasta_reader->next()) {
my $sequence = $seq_obj->get_sequence();
my $seq_len = length($sequence);
$cum_seq_len += $seq_len;
push (@seq_lengths, $seq_len);
}
@seq_lengths = reverse sort {$a<=>$b} @seq_lengths;
my $half_cum_len = $cum_seq_len / 2;
my $partial_sum_len = 0;
foreach my $len (@seq_lengths) {
$partial_sum_len += $len;
if ($partial_sum_len >= $half_cum_len) {
print "N50: $len\n";
last;
}
}
exit(0);
}
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