biyelunwen/99.scripts/trinity_utils/util/misc/examine_strand_specificity.pl

93 lines
2.7 KiB
Perl

#!/usr/bin/env perl
use strict;
use warnings;
use FindBin;
use lib ("$FindBin::Bin/../../PerlLib");
use SAM_reader;
use SAM_entry;
use Process_cmd;
my $usage = "\n\n\tusage: $0 transcript_aligned.bam [out_prefix='ss_analysis']\n\n";
my $bam_file = $ARGV[0] or die $usage;
my $out_prefix = $ARGV[1] || "ss_analysis";
main: {
my %transcript_to_orients;
my $sam_reader = new SAM_reader($bam_file);
print STDERR "-parsing file: $bam_file\n";
while (my $sam_entry = $sam_reader->get_next()) {
my $trans_name = $sam_entry->get_scaffold_name();
my $orient = $sam_entry->get_query_strand();
if ($sam_entry->is_paired()) {
unless ($sam_entry->is_proper_pair() && $sam_entry->is_first_in_pair()) {
next;
}
}
$transcript_to_orients{$trans_name}->{$orient}++;
}
print STDERR "-done parsing file, examining orientations of reads.\n";
## sum them up.
my @transcripts = keys %transcript_to_orients;
foreach my $transcript (@transcripts) {
my $orient_plus = $transcript_to_orients{$transcript}->{'+'} || 0;
my $orient_minus = $transcript_to_orients{$transcript}->{'-'} || 0;
my $total_reads = $orient_plus + $orient_minus;
$transcript_to_orients{$transcript}->{'transcript'} = $transcript;
$transcript_to_orients{$transcript}->{'total_reads'} = $total_reads;
}
####
my @structs = values %transcript_to_orients;
@structs = reverse sort {$a->{total_reads}<=>$b->{total_reads}} @structs;
# header
open (my $ofh, ">$out_prefix.dat") or die "Error, cannot write to $out_prefix.dat";
print $ofh join("\t", "#transcript", "plus_strand_1stReads", "minus_strand_1stReads", "total_reads", "diff_ratio") . "\n";
foreach my $struct (@structs) {
my $struct = shift @structs;
my ($plus, $minus, $total_reads, $transcript) = ($struct->{'+'},
$struct->{'-'},
$struct->{'total_reads'},
$struct->{'transcript'});
unless ($plus) { $plus = 0; }
unless ($minus) { $minus = 0; }
my $diff_proportion = sprintf("%.3f", ($plus - $minus) / $total_reads);
print $ofh join("\t", $transcript, $plus, $minus, $total_reads, $diff_proportion) . "\n";
}
close $ofh;
## plot it.
my $cmd = "$FindBin::Bin/plot_strand_specificity_dist_by_quantile.Rscript $out_prefix.dat";
&process_cmd($cmd);
exit(0);
}