Bio::Index::Blast(3p)

NAME
Bio::Index::Blast - Indexes Blast reports and supports retrieval based on query accession(s)

SYNOPSIS
  use strict;
  use Bio::Index::Blast;

  my ($indexfile,$file1,$file2,$query);
  my $index = Bio::Index::Blast->new(-filename => $indexfile,
                                                         -write_flag => 1);
  $index->make_index($file1,$file2);

  my $fh = $index->get_stream($query);

  my $blast_report = Bio::SearchIO->new(-noclose => 1,
                                        -format  => 'blast',
                                        -fh      => $fh);
  my $result = $blast_report->next_result;
  print $result->algorithm, "\n";
  my $hit = $result->next_hit;
  print $hit->description, "\n";
  my $hsp = $hit->next_hsp;
  print $hsp->bits, "\n";

DESCRIPTION
This object allows one to build an index on a blast file (or files) and provide quick access to the blast report for that accession.

This also allows for ID parsing using a callback:

   $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 =~ /^gi\|(\d+)/;
      $1;
   }

The indexer is capable of indexing based on multiple IDs passed back from the callback; this is assuming of course all IDs are unique.

Note: for best results 'use strict'.

FEEDBACK

  Mailing Lists
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/wiki/Mailing_lists  - About the mailing lists

  Support
Please direct usage questions or support issues to the mailing list:

bioperl-l@bioperl.org

rather than to the module maintainer directly. Many experienced and reponsive experts will be able look at the problem and quickly address it. Please include a thorough description of the problem with code and data examples if at all possible.

  Reporting Bugs
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 the web:

  https://github.com/bioperl/bioperl-live/issues

AUTHOR - Jason Stajich
Email jason-at-bioperl-dot-org

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

  new
  Usage   : $index = Bio::Index::Abstract->new(
                -filename    => $dbm_file,
                -write_flag  => 0,
                -dbm_package => 'DB_File',
                -verbose     => 0);

  Function: Returns a new index object.  If filename is
            specified, then open_dbm() is immediately called.
            Bio::Index::Abstract->new() will usually be called
            directly only when opening an existing index.
  Returns : A new index object
  Args    : -filename    The name of the dbm index file.
            -write_flag  TRUE if write access to the dbm file is
                         needed.
            -dbm_package The Perl dbm module to use for the
                         index.
            -verbose     Print debugging output to STDERR if
                         TRUE.

  Bio::Index::Blast implemented methods

  fetch_report
 Title   : fetch_report
 Usage   : my $blastreport = $idx->fetch_report($id);
 Function: Returns a Bio::SearchIO report object
           for a specific blast report
 Returns : Bio::SearchIO
 Args    : valid id

  fetch_result
 Title   : fetch_result
 Usage   : my $blastreport = $idx->fetch_result($id);
 Function: Returns a Bio::SearchIO report object
           for a specific blast report
 Returns : Bio::SearchIO
 Args    : valid id
 Note    : alias of fetch_report()

  Require methods from Bio::Index::Abstract

  _index_file
  Title   : _index_file
  Usage   : $index->_index_file( $file_name, $i )
  Function: Specialist function to index BLAST report file(s).
            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 blast dbs.
            Returns \&default_id_parser (see below) if not
            set. If you supply your own id_parser
            subroutine, then it should expect a fasta
            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 Blast Query ID parser for Bio::Index::Blast.pm
            Returns $1 from applying the regexp /^>\s*(\S+)/
            to $header.
  Returns : ID string
  Args    : a header line string

  blast_parser_type
  Title   : blast_parser_type
  Usage   : $index->blast_parser_type() # returns
  Function: Get/Set SearchIO-based text (-m0) BLAST parser. Only values in
            local %VALID_PARSERS hash allowed.
  Returns : String
  Args    : [optional]
  Note    : This only allows simple text-based parsing options; tabular, XML,
            or others are not supported (see Bio::Index::BlastTable for tab
            output).

  Bio::Index::Abstract methods

  filename
 Title   : filename
 Usage   : $value = $self->filename();
           $self->filename($value);
 Function: Gets or sets the name of the dbm index file.
 Returns : The current value of filename
 Args    : Value of filename if setting, or none if
           getting the value.

  write_flag
 Title   : write_flag
 Usage   : $value = $self->write_flag();
           $self->write_flag($value);
 Function: Gets or sets the value of write_flag, which
           is whether the dbm file should be opened with
           write access.
 Returns : The current value of write_flag (default 0)
 Args    : Value of write_flag if setting, or none if
           getting the value.

  dbm_package
 Usage   : $value = $self->dbm_package();
           $self->dbm_package($value);

 Function: Gets or sets the name of the Perl dbm module used.
           If the value is unset, then it returns the value of
           the package variable $USE_DBM_TYPE or if that is
           unset, then it chooses the best available dbm type,
           choosing 'DB_File' in preference to 'SDBM_File'.
           Bio::Abstract::Index may work with other dbm file
           types.

 Returns : The current value of dbm_package
 Args    : Value of dbm_package if setting, or none if
           getting the value.

  get_stream
 Title   : get_stream
 Usage   : $stream = $index->get_stream( $id );
 Function: Returns a file handle with the file pointer
           at the approprite place

           This provides for a way to get the actual
           file contents and not an object

           WARNING: you must parse the record deliminter
           *yourself*. Abstract won't do this for you
           So this code

           $fh = $index->get_stream($myid);
           while( <$fh> ) {
              # do something
           }
           will parse the entire file if you do not put in
           a last statement in, like

           while( <$fh> ) {
              /^\/\// && last; # end of record
              # do something
           }

 Returns : A filehandle object
 Args    : string represents the accession number
 Notes   : This method should not be used without forethought

  open_dbm
  Usage   : $index->open_dbm()
  Function: Opens the dbm file associated with the index
            object.  Write access is only given if explicitly
            asked for by calling new(-write => 1) or having set
            the write_flag(1) on the index object.  The type of
            dbm file opened is that returned by dbm_package().
            The name of the file to be is opened is obtained by
            calling the filename() method.

  Example : $index->_open_dbm()
  Returns : 1 on success

  _version
  Title   : _version
  Usage   : $type = $index->_version()
  Function: Returns a string which identifes the version of an
            index module.  Used to permanently identify an index
            file as having been created by a particular version
            of the index module.  Must be provided by the sub class
  Example :
  Returns :
  Args    : none

  _filename
  Title   : _filename
  Usage   : $index->_filename( FILE INT )
  Function: Indexes the file
  Example :
  Returns :
  Args    :

  _file_handle
  Title   : _file_handle
  Usage   : $fh = $index->_file_handle( INT )
  Function: Returns an open filehandle for the file
            index INT.  On opening a new filehandle it
            caches it in the @{$index->_filehandle} array.
            If the requested filehandle is already open,
            it simply returns it from the array.
  Example : $fist_file_indexed = $index->_file_handle( 0 );
  Returns : ref to a filehandle
  Args    : INT

  _file_count
  Title   : _file_count
  Usage   : $index->_file_count( INT )
  Function: Used by the index building sub in a sub class to
            track the number of files indexed.  Sets or gets
            the number of files indexed when called with or
            without an argument.
  Example :
  Returns : INT
  Args    : INT

  add_record
  Title   : add_record
  Usage   : $index->add_record( $id, @stuff );
  Function: Calls pack_record on @stuff, and adds the result
            of pack_record to the index database under key $id.
            If $id is a reference to an array, then a new entry
            is added under a key corresponding to each element
            of the array.
  Example : $index->add_record( $id, $fileNumber, $begin, $end )
  Returns : TRUE on success or FALSE on failure
  Args    : ID LIST

  pack_record
  Title   : pack_record
  Usage   : $packed_string = $index->pack_record( LIST )
  Function: Packs an array of scalars into a single string
            joined by ASCII 034 (which is unlikely to be used
            in any of the strings), and returns it.
  Example : $packed_string = $index->pack_record( $fileNumber, $begin, $end )
  Returns : STRING or undef
  Args    : LIST

  unpack_record
  Title   : unpack_record
  Usage   : $index->unpack_record( STRING )
  Function: Splits the sting provided into an array,
            splitting on ASCII 034.
  Example : ( $fileNumber, $begin, $end ) = $index->unpack_record( $self->db->{$id} )
  Returns : A 3 element ARRAY
  Args    : STRING containing ASCII 034

  DESTROY
 Title   : DESTROY
 Usage   : Called automatically when index goes out of scope
 Function: Closes connection to database and handles to
           sequence files
 Returns : NEVER
 Args    : NONE