Bio::Index
Blast
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Summary
Bio::Index::Blast - Indexes Blast reports and supports retrieval based on query accession(s)
Package variables
No package variables defined.
Included modules
Inherit
Synopsis
use strict;
use Bio::Index::Blast;
my $index = new Bio::Index::Blast(-filename => $indexfile,
-write_flag => 1);
$index->make_index($file1, $file2);
my $data = $index->get_stream($id);
my $bplite_report = $index->fetch_report($id);
print "query is ", $bplite_report->query, "\n";
while( my $sbjct = $bplite_report->nextSbjct ) {
print $sbjct->name, "\n";
while( my $hsp = $sbjct->nextHSP ) {
print "\t e-value ", $hsp->P,
}
print "\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.
Note: for best results 'use strict'.
Methods
Methods description
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 : |
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 |
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 |
Title : fetch_report Usage : my $blastreport = $idx->fetch_report($id); Function: Returns a Bio::Tools::BPlite report object for a specific blast report Returns : Bio::Tools::BPlite Args : valid id |
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 |
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. |
Methods code
sub _index_file
{ my( $self,
$file, $i, ) = @_;
my( $begin, );
open(BLAST, "<$file") or die("cannot open file $file\n");
my (@data, @records);
my $indexpoint = 0;
my $lastline = 0;
while(<BLAST> ) {
if( /(T)?BLAST[PNX]/ ) {
if( @data ) {
$self->_process_report($indexpoint, $i,join("",@data));
}
$indexpoint = $lastline;
@data = ();
}
push @data, $_;
$lastline = tell(BLAST);
}
if( @data ) {
$self->_process_report($indexpoint,$i,join("",@data));
} } |
sub _process_report
{ my ($self,$begin,$i,$data) = @_;
if( ! $data ) {
$self->warn("calling _process_report without a valid data string");
return ;
}
my $id_parser = $self->id_parser;
my $datal = new IO::String($data);
my $report = new Bio::Tools::BPlite(-fh => $datal,
-noclose => 1);
my $query = $report->query;
foreach my $id (&$id_parser($query)) {
print "id is $id, begin is $begin\n" if( $self->verbose > 0);
$self->add_record($id, $i, $begin);
} } |
sub _version
{ return $VERSION; } |
sub default_id_parser
{ if ($_[0] =~ /^\s*(\S+)/) {
return $1;
} else {
return;
} } |
sub fetch_report
{ my ($self,$id) = @_;
my $fh = $self->get_stream($id);
my $report = new Bio::Tools::BPlite(-fh => $fh,
-noclose => 1);
return $report;
}
} |
sub id_parser
{ my( $self, $code ) = @_;
if ($code) {
$self->{'_id_parser'} = $code;
}
return $self->{'_id_parser'} ||\& default_id_parser; } |
sub new
{
my($class,@args) = @_;
my $self = $class->SUPER::new(@args); } |
General documentation
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
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 - Jason Stajich | Top |
The rest of the documentation details each of the object methods.
Internal methods are usually preceded with a _
Bio::Index::Blast implemented methods | Top |
Require methods from Bio::Index::Abstract | Top |
Bio::Index::Abstract methods | Top |
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.
Title : write_flag
Usage : $value = $self->write_flag();
$self->write_flag($value);
Function: Gets or sets the value of write_flag, which
is wether 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.
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.
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 wont do this for you
So this code
$fh = $index->get_stream($myid);
while( <$fh> ) {
# do something
}
will parse the entire file if you don't put in
a last statement in, like
while( <$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
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
Title : _filename
Usage : $index->_filename( FILE INT )
Function: Indexes the file
Example :
Returns :
Args :
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
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
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
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
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
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