Merge pull request 'UMI deduplication script from Victor' (#3) from s3970582/system_genetics:master into master

Reviewed-on: #3

rnaseq/umi/07_remove_dups.pl

@@ -0,0 +1,60 @@
+#!/usr/bin/perl -w
+use strict;
+use Parallel::ForkManager;
+# this script creats one file with UMI unique reads and one with UMI duplicated reads
+my @torun = ();
+foreach my $file ( <*Aligned.sortedByCoord.out.bam> ) {
+    push @torun, $file;
+}
+
+my $pm = Parallel::ForkManager->new( 12 );
+foreach my $file ( @torun ) {
+    my $sample = $file;
+    $sample =~ s/Aligned\.sortedByCoord\.out\.bam$//;
+    next if -s $sample.'_uniq.bam';
+    warn "Parsing $sample\n";
+    $pm->start and next;
+    my %seen = ();
+    my %duplicates = ();
+    my ( $uniqs, $dups ) = ( 0, 0 );
+    open F, 'samtools view -h '.$file.' |';
+    open F1, '| samtools view -bS - >'.$sample.'_uniq.bam';
+    open F2, '| samtools view -bS - >'.$sample.'_dups.bam';
+    while ( <F> ) {
+        if ( m/^\@/ ) {
+            print F1;
+            print F2;
+            next;
+        }
+        my ( $id, $flag, $chr, $pos, $mapq, $cigar, $chr2, $pos2, $tlen ) = split /\t/;
+        next if $flag & 256 or $flag & 512 or $flag & 1024; #skip if the read is not primary alignment/read fails platform/vendor quality checks/read is PCR or optical duplicate
+#        foreach ( 256, 512, 1024 ) { $flag-=$_ if $flag&$_ }
+        my ( $bc ) = $id =~ m/\:([GATCN\d]+)$/; #extract UMI barcode
+        my $uniq = join( ':', $chr, $pos, $flag, $tlen, $bc );
+        my $pos_ = $pos-1;
+        while ( $cigar =~ m/(\d+)([SHMDIN=])/g ) {
+            $pos_+=$1 if $2 eq 'M' or $2 eq '=' or $2 eq 'D' or $2 eq 'N'; 
+        }
+        my $uniq2 = join( ':', $chr, $pos_, $flag, $tlen, $bc );
+        if ( exists($duplicates{$id}) or # already marked as duplicate
+            ( not($flag&16) and ++$seen{ $uniq } > 1 ) or # plus strand
+            ( $flag&16 and ++$seen{ $uniq2 } > 1 )
+            ) {
+            print F2;
+            $dups++;
+            $duplicates{$id} = 1;
+        }
+        else {
+            print F1;
+            $uniqs++;
+        }
+    }
+    close F;
+    close F1;
+    close F2;
+    warn "Unique: $uniqs (", 100*$uniqs/($uniqs+$dups), ")\n";
+    system( 'samtools', 'index', $sample.'_uniq.bam' );
+#    last;
+    $pm->finish;
+}
+$pm->wait_all_children;