Bio::Tools Blat
SummaryIncluded librariesPackage variablesSynopsisDescriptionGeneral documentationMethods
Summary
Bio::Tools::Blat
Package variables
No package variables defined.
Included modules
Bio::Root::IO
Bio::Root::Root
Bio::SeqFeature::FeaturePair
Bio::SeqFeature::Generic(1)
Bio::SeqFeature::Generic(2)
Inherit
Bio::Root::IO Bio::Root::Root
Synopsis
  use Bio::Tools::Blat;
  my $blat_parser = new Bio::Tools::Blat(-fh =>$filehandle );
  while( my $blat_feat = $blat_parser->next_result ) {
        push @bllat_feat, $blat_feat;
  }
Description
 Parser for Blat  program
Methods
newDescriptionCode
next_resultDescriptionCode
create_featureDescriptionCode
Methods description
newcode    nextTop
 Title   : new
 Usage   : my $obj = new Bio::Tools::Blat(-fh=>$filehandle);
 Function: Builds a new Bio::Tools::Blat object
 Returns : Bio::Tools::Blat
 Args    : -filename
           -fh (filehandle)
next_resultcodeprevnextTop
 Title   : next_result
 Usage   : my $feat = $blat_parser->next_result
 Function: Get the next result set from parser data
 Returns : Bio::SeqFeature::Generic
Args : none
create_featurecodeprevnextTop
 Title   : create_feature
 Usage   : my $feat=$blat_parser->create_feature($feature,$seqname)
 Function: creates a SeqFeature Generic object
 Returns : Bio::SeqFeature::Generic
Args :
Methods code
newdescriptionprevnextTop
sub new {
      my($class,@args) = @_;

      my $self = $class->SUPER::new(@args);
      $self->_initialize_io(@args);

      return $self;
}
next_resultdescriptionprevnextTop
sub next_result {
    my ($self) = @_;
    my $filehandle;
    
 my $line;

    my $id;
 while ($_=$self->_readline()){
   
    # first split on spaces:
$line = $_; chomp $line; # chomp;
my ( $matches, $mismatches, $rep_matches, $n_count, $q_num_insert, $q_base_insert, $t_num_insert, $t_base_insert, $strand, $q_name, $q_length, $q_start, $q_end, $t_name, $t_length, $t_start, $t_end, $block_count, $block_sizes, $q_starts, $t_starts ) = split; my $superfeature = Bio::SeqFeature::Generic->new(); # ignore any preceeding text
unless ( $matches =~/^\d+$/ ){ next; } # create as many features as blocks there are in each output line
my (%feat1, %feat2); $feat1{name} = $t_name; $feat2{name} = $q_name; $feat2{strand} = 1; $feat1{strand} = $strand; my $percent_id = sprintf "%.2f", ( 100 * ($matches + $rep_matches)/( $matches + $mismatches + $rep_matches )
);
unless ( $q_length ){ $self->warn("length of query is zero, something is wrong!"); next; } my $score = sprintf "%.2f", ( 100 * ( $matches + $mismatches + $rep_matches ) / $q_length );
# size of each block of alignment (inclusive)
my @block_sizes = split ",",$block_sizes; # start position of each block (you must add 1 as psl output is off by one in the start coordinate)
my @q_start_positions = split ",",$q_starts; my @t_start_positions = split ",",$t_starts; $superfeature->seq_id($q_name); $superfeature->score( $score ); #$superfeature->percent_id( $percent_id );
$superfeature->add_tag_value('percent_id',$percent_id); # each line of output represents one possible entire aligment of the query (feat1) and the target(feat2)
for (my $i=0; $i<$block_count; $i++ ){ my ($query_start,$query_end); if ( $strand eq '+' ){ $query_start = $q_start_positions[$i] + 1; $query_end = $query_start + $block_sizes[$i] - 1; } else{ $query_end = $q_length - $q_start_positions[$i]; $query_start = $query_end - $block_sizes[$i] + 1; } #$feat2 {start} = $q_start_positions[$i] + 1;
#$feat2 {end} = $feat2{start} + $block_sizes[$i] - 1;
$feat2 {start} = $query_start; $feat2 {end} = $query_end; if ( $query_end < $query_start ){ $self->warn("dodgy feature coordinates: end = $query_end, start = $query_start. Reversing..."); $feat2 {end} = $query_start; $feat2 {start} = $query_end; } $feat1 {start} = $t_start_positions[$i] + 1; $feat1 {end} = $feat1{start} + $block_sizes[$i] - 1; # we put all the features with the same score and percent_id
$feat2 {score} = $score; $feat1 {score} = $feat2 {score}; $feat2 {percent} = $percent_id; $feat1 {percent} = $feat2 {percent}; # other stuff:
$feat1 {db} = undef; $feat1 {db_version} = undef; $feat1 {program} = 'blat'; $feat1 {p_version} = '1'; $feat1 {source} = 'blat'; $feat1 {primary} = 'similarity'; $feat2 {source} = 'blat'; $feat2 {primary} = 'similarity'; my $feature_pair = $self->create_feature(\%feat1,\% feat2); $superfeature->add_sub_SeqFeature( $feature_pair,'EXPAND'); } #push(@features_within_features, $superfeature);
return $superfeature; }
}
create_featuredescriptionprevnextTop
sub create_feature {
    my ($self, $feat1,$feat2) = @_;



    my $feature1= Bio::SeqFeature::Generic->new( -seq_id     =>$feat1->{name},
                                                 -start      =>$feat1->{start},
                                                 -end        =>$feat1->{end},
                                                 -strand     =>$feat1->{strand},
                                                 -score      =>$feat1->{score},
                                                 -source     =>$feat1->{source},
                                                 -primary    =>$feat1->{primary},
                                                   );
    


    my $feature2= Bio::SeqFeature::Generic->new( -seq_id     =>$feat2->{name}, 
                                                 -start      =>$feat2->{start},
                                                 -end        =>$feat2->{end},
                                                 -strand     =>$feat2->{strand},
                                                 -score      =>$feat2->{score},
                                                 -source     =>$feat2->{source},
                                                 -primary    =>$feat2->{primary},
                                                  );




    my $featurepair = Bio::SeqFeature::FeaturePair->new;
    $featurepair->feature1 ($feature1);
    $featurepair->feature2 ($feature2);
   
   $featurepair->add_tag_value('evalue',$feat2->{p});
   $featurepair->add_tag_value('percent_id',$feat2->{percent});
   $featurepair->add_tag_value("hid",$feat2->{primary});
    return  $featurepair;
}
General documentation
FEEDBACKTop
Mailing ListsTop
 User feedback is an integral part of the evolution of this and other
 Bioperl modules. Send your comments and suggestions preferably to
 the Bioperl mailing list.  Your participation is much appreciated.

 bioperl-l@bioperl.org              - General discussion
 http://bioperl.org/MailList.shtml  - About the mailing lists
Reporting BugsTop
 Report bugs to the Bioperl bug tracking system to help us keep track
 of the bugs and their resolution. Bug reports can be submitted via
 email or the web:

 bioperl-bugs@bioperl.org
 http://bugzilla.bioperl.org/
AUTHOR - Balamurugan KumarasamyTop
 Email: bala@tll.org.sg
APPENDIXTop
 The rest of the documentation details each of the object methods.
 Internal methods are usually preceded with a _