Bio::Index::Qual(3)

NAME
Bio::Index::Qual - Interface for indexing (multiple) fasta qual files

SYNOPSIS
    # Complete code for making an index for several
    # qual files
    use Bio::Index::Qual;
    use strict;

    my $Index_File_Name = shift;
    my $inx = Bio::Index::Qual->new(
        '-filename' => $Index_File_Name,
        '-write_flag' => 1);
    $inx->make_index(@ARGV);

    # Print out several sequences present in the index
    # in Qual format
    use Bio::Index::Qual;
    use strict;

    my $Index_File_Name = shift;
    my $inx = Bio::Index::Qual->new('-filename' => $Index_File_Name);
    my $out = Bio::SeqIO->new('-format' => 'qual','-fh' => \*STDOUT);

    foreach my $id (@ARGV) {
        my $seq = $inx->fetch($id); # Returns Bio::Seq object
        $out->write_seq($seq);
    }

    # or, alternatively
    my $id;
    my $seq = $inx->get_Seq_by_id($id); #identical to fetch

DESCRIPTION
Inherits functions for managing dbm files from Bio::Index::Abstract.pm, and provides the basic funtionallity for indexing qual files, and retrieving the sequence from them. For best results 'use strict'.

Bio::Index::Qual supports the Bio::DB::BioSeqI interface, meaning it can be used as a Sequence database for other parts of bioperl

Additional example code is available in scripts/index/*PLS and in the Bioperl Tutorial (<http://www.bioperl.org/wiki/Bptutorial.pl>).

Note that by default the key for the sequence will be the first continuous string after the '>' in the qual header. If you want to use a specific substring of the qual header you must use the id_parser() method.

You can also set or customize the unique key used to retrieve by writing your own function and calling the id_parser() method. For example:

   $inx->id_parser(\&get_id);
   # make the index
   $inx->make_index($file_name);

   # here is where the retrieval key is specified
   sub get_id {
      my $line = shift;
      $line =~ /^(\d+)/;
      $1;
   }

FEED_BACK

  Mailing Lists
User feedback is an integral part of the evolution of this and other Bioperl modules. Send your comments and suggestions preferably to one of the Bioperl mailing lists. Your participation is much appreciated.

  bioperl-l@bioperl.org                  - General discussion
  http://bioperl.org/wiki/Mailing_lists  - About the mailing lists

  Reporting Bugs
Report bugs to the Bioperl bug tracking system to help us keep track the bugs and their resolution. Bug reports can be submitted via the web:

  http://bugzilla.open-bio.org/

AUTHOR - James Gilbert, Mark Johnson
Email - jgrg@sanger.ac.uk, mjohnson@watson.wustl.edu

APPENDIX
The rest of the documentation details each of the object methods. Internal methods are usually preceded with a _

  _file_format
 Title   : _file_format
 Function: The file format for this package, which is needed
           by the SeqIO system when reading the sequence.
 Returns : 'qual'

  _index_file
  Title   : _index_file
  Usage   : $index->_index_file( $file_name, $i )
  Function: Specialist function to index QUAL format files.
            Is provided with a filename and an integer
            by make_index in its SUPER class.
  Example :
  Returns :
  Args    :

  id_parser
  Title   : id_parser
  Usage   : $index->id_parser( CODE )
  Function: Stores or returns the code used by record_id to
            parse the ID for record from a string.  Useful
            for (for instance) specifying a different
            parser for different flavours of Qual file.
            Returns \&default_id_parser (see below) if not
            set. If you supply your own id_parser
            subroutine, then it should expect a qual
            description line.  An entry will be added to
            the index for each string in the list returned.
  Example : $index->id_parser( \&my_id_parser )
  Returns : ref to CODE if called without arguments
  Args    : CODE

  default_id_parser
  Title   : default_id_parser
  Usage   : $id = default_id_parser( $header )
  Function: The default Qual ID parser for Qual.pm
            Returns $1 from applying the regexp /^>\s*(\S+)/
            to $header.
  Returns : ID string
  Args    : a qual header line string