Provided by: libbio-db-gff-perl_1.7.4-1_all 
NAME
Bio::DB::GFF::Adaptor::dbi -- Database adaptor for DBI (SQL) databases
SYNOPSIS
See Bio::DB::GFF
DESCRIPTION
This is the base class for DBI-based adaptors. It does everything except generating the
text of the queries to be used. See the section QUERIES TO IMPLEMENT for the list of
methods that must be implemented.
new
Title : new
Usage : $db = Bio::DB::GFF->new(@args)
Function: create a new adaptor
Returns : a Bio::DB::GFF object
Args : see below
Status : Public
This is the constructor for the adaptor. It is called automatically by Bio::DB::GFF->new.
In addition to arguments that are common among all adaptors, the following class-specific
arguments are recgonized:
Argument Description
-------- -----------
-dsn the DBI data source, e.g. 'dbi:mysql:ens0040'
-user username for authentication
-pass the password for authentication
features_db
Title : features_db
Usage : $dbh = $db->features_db
Function: get database handle
Returns : a DBI handle
Args : none
Status : Public
Note: what is returned is not really a DBI::db handle, but a
subclass of one. This means that you cannot manipulate the
handle's attributes directly. Instead call the attribute
method:
my $dbh = $db->features_db;
$dbh->attribute(AutoCommit=>0);
get_dna
Title : get_dna
Usage : $string = $db->get_dna($name,$start,$stop,$class)
Function: get DNA string
Returns : a string
Args : name, class, start and stop of desired segment
Status : Public
This method performs the low-level fetch of a DNA substring given its name, class and the
desired range. It is actually a front end to the abstract method make_dna_query(), which
it calls after some argument consistency checking.
get_abscoords
Title : get_abscoords
Usage : ($refseq,$refclass,$start,$stop,$strand) = $db->get_abscoords($name,$class)
Function: get absolute coordinates for landmark
Returns : an array ref -- see below
Args : name and class of desired landmark
Status : Public
This method performs the low-level resolution of a landmark into a reference sequence and
position.
The result is an array ref, each element of which is a five-element list containing
reference sequence name, class, start, stop and strand.
get_features
Title : get_features
Usage : $db->get_features($search,$options,$callback)
Function: retrieve features from the database
Returns : number of features retrieved
Args : see below
Status : Public
This is the low-level method that is called to retrieve GFF lines from the database. It
is responsible for retrieving features that satisfy range and feature type criteria, and
passing the GFF fields to a callback subroutine.
See the manual page for Bio::DB::GFF for the interpretation of the arguments and how the
information retrieved by get_features is passed to the callback for processing.
Internally, get_features() is a front end for range_query(). The latter method constructs
the query and executes it. get_features() calls fetchrow_array() to recover the fields
and passes them to the callback.
classes
Title : classes
Usage : $db->classes
Function: return list of landmark classes in database
Returns : a list of classes
Args : none
Status : public
This routine returns the list of reference classes known to the database, or empty if
classes are not used by the database. Classes are distinct from types, being essentially
qualifiers on the reference namespaces.
NOTE: In the current mysql-based schema, this query takes a while to run due to the
classes not being normalized.
make_classes_query
Title : make_classes_query
Usage : ($query,@args) = $db->make_classes_query
Function: return query fragment for generating list of reference classes
Returns : a query and args
Args : none
Status : public
_feature_by_name
Title : _feature_by_name
Usage : $db->get_features_by_name($name,$class,$callback)
Function: get a list of features by name and class
Returns : count of number of features retrieved
Args : name of feature, class of feature, and a callback
Status : protected
This method is used internally. The callback arguments are those used by make_feature().
Internally, it invokes the following abstract procedures:
make_features_select_part
make_features_from_part
make_features_by_name_where_part
make_features_by_alias_where_part (for aliases)
make_features_join_part
_feature_by_id
Title : _feature_by_id
Usage : $db->_feature_by_id($ids,$type,$callback)
Function: get a list of features by ID
Returns : count of number of features retrieved
Args : arrayref containing list of IDs to fetch and a callback
Status : protected
This method is used internally. The $type selector is one of "feature" or "group". The
callback arguments are those used by make_feature(). Internally, it invokes the following
abstract procedures:
make_features_select_part
make_features_from_part
make_features_by_id_where_part
make_features_join_part
get_types
Title : get_types
Usage : $db->get_types($refseq,$refclass,$start,$stop,$count)
Function: get list of types
Returns : a list of Bio::DB::GFF::Typename objects
Args : see below
Status : Public
This method is responsible for fetching the list of feature type names from the database.
The query may be limited to a particular range, in which case the range is indicated by a
landmark sequence name and class and its subrange, if any. These arguments may be undef
if it is desired to retrieve all feature types in the database (which may be a slow
operation in some implementations).
If the $count flag is false, the method returns a simple list of vBio::DB::GFF::Typename
objects. If $count is true, the method returns a list of $name=>$count pairs, where
$count indicates the number of times this feature occurs in the range.
Internally, this method calls upon the following functions to generate the SQL and its
bind variables:
($q1,@args) = make_types_select_part(@args);
($q2,@args) = make_types_from_part(@args);
($q3,@args) = make_types_where_part(@args);
($q4,@args) = make_types_join_part(@args);
($q5,@args) = make_types_group_part(@args);
The components are then combined as follows:
$query = "SELECT $q1 FROM $q2 WHERE $q3 AND $q4 GROUP BY $q5";
If any of the query fragments contain the ? bind variable, then the same number of bind
arguments must be provided in @args. The fragment-generating functions are described
below.
range_query
Title : range_query
Usage : $db->range_query($range_type,$refseq,$refclass,$start,$stop,$types,$order_by_group,$attributes,$binsize)
Function: create statement handle for range/overlap queries
Returns : a DBI statement handle
Args : see below
Status : Protected
This method constructs the statement handle for this module's central query: given a range
and/or a list of feature types, fetch their GFF records.
The positional arguments are as follows:
Argument Description
$isrange A flag indicating that this is a range.
query. Otherwise an overlap query is
assumed.
$refseq The reference sequence name (undef if no range).
$refclass The reference sequence class (undef if no range).
$start The start of the range (undef if none).
$stop The stop of the range (undef if none).
$types Array ref containing zero or feature types in the
format [method,source].
$order_by_group A flag indicating that statement handler should group
the features by group id (handy for iterative fetches)
$attributes A hash containing select attributes.
$binsize A bin size for generating tables of feature density.
If successful, this method returns a statement handle. The handle is expected to return
the fields described for get_features().
Internally, range_query() makes calls to the following methods, each of which is expected
to be overridden in subclasses:
$select = $self->make_features_select_part;
$from = $self->make_features_from_part;
$join = $self->make_features_join_part;
($where,@args) = $self->make_features_by_range_where_part($isrange,$srcseq,$class,
$start,$stop,$types,$class);
The query that is constructed looks like this:
SELECT $select FROM $from WHERE $join AND $where
The arguments that are returned from make_features_by_range_where_part() are passed to the
statement handler's execute() method.
range_query() also calls a do_straight_join() method, described below. If this method
returns true, then the keyword "straight_join" is inserted right after SELECT.
make_features_by_range_where_part
Title : make_features_by_range_where_part
Usage : ($string,@args) =
$db->make_features_select_part($isrange,$refseq,$class,$start,$stop,$types)
Function: make where part of the features query
Returns : the list ($query,@bind_args)
Args : see below
Status : Protected
This method creates the part of the features query that immediately follows the WHERE
keyword and is ANDed with the string returned by make_features_join_part().
The six positional arguments are a flag indicating whether to perform a range search or an
overlap search, the reference sequence, class, start and stop, all of which define an
optional range to search in, and an array reference containing a list [$method,$souce]
pairs.
The method result is a multi-element list containing the query string and the list of
runtime arguments to bind to it with the execute() method.
This method's job is to clean up arguments and perform consistency checking. The real
work is done by the following abstract methods:
Method Description
refseq_query() Return the query string needed to match the reference
sequence.
range_query() Return the query string needed to find all features contained
within a range.
overlap_query() Return the query string needed to find all features that overlap
a range.
See Bio::DB::Adaptor::dbi::mysql for an example of how this works.
do_straight_join
Title : do_straight_join
Usage : $boolean = $db->do_straight_join($refseq,$class,$start,$stop,$types)
Function: optimization flag
Returns : a flag
Args : see range_query()
Status : Protected
This subroutine, called by range_query() returns a boolean flag. If true, range_query()
will perform a straight join, which can be used to optimize certain SQL queries. The four
arguments correspond to similarly-named arguments passed to range_query().
string_match
Title : string_match
Usage : $string = $db->string_match($field,$value)
Function: create a SQL fragment for performing exact or regexp string matching
Returns : query string
Args : the table field and match value
Status : public
This method examines the passed value for meta characters. If so it produces a SQL
fragment that performs a regular expression match. Otherwise, it produces a fragment that
performs an exact string match.
This method is not used in the module, but is available for use by subclasses.
exact_match
Title : exact_match
Usage : $string = $db->exact_match($field,$value)
Function: create a SQL fragment for performing exact string matching
Returns : query string
Args : the table field and match value
Status : public
This method produces the SQL fragment for matching a field name to a constant string
value.
search_notes
Title : search_notes
Usage : @search_results = $db->search_notes("full text search string",$limit)
Function: Search the notes for a text string, using mysql full-text search
Returns : array of results
Args : full text search string, and an optional row limit
Status : public
This is a mysql-specific method. Given a search string, it performs a full-text search of
the notes table and returns an array of results. Each row of the returned array is a
arrayref containing the following fields:
column 1 A Bio::DB::GFF::Featname object, suitable for passing to segment()
column 2 The text of the note
column 3 A relevance score.
column 4 A Bio::DB::GFF::Typename object
meta
Title : meta
Usage : $value = $db->meta($name [,$newval])
Function: get or set a meta variable
Returns : a string
Args : meta variable name and optionally value
Status : public
Get or set a named metavariable for the database. Metavariables can be used for database-
specific settings. This method calls two class-specific methods which must be
implemented:
make_meta_get_query() Returns a sql fragment which given a meta
parameter name, returns its value. One bind
variable.
make_meta_set_query() Returns a sql fragment which takes two bind
arguments, the parameter name and its value
Don't make changes unless you know what you're doing! It will affect the persistent
database.
make_meta_get_query
Title : make_meta_get_query
Usage : $sql = $db->make_meta_get_query
Function: return SQL fragment for getting a meta parameter
Returns : SQL fragment
Args : none
Status : public
By default this does nothing; meta parameters are not stored or retrieved.
make_meta_set_query
Title : make_meta_set_query
Usage : $sql = $db->make_meta_set_query
Function: return SQL fragment for setting a meta parameter
Returns : SQL fragment
Args : none
Status : public
By default this does nothing; meta parameters are not stored or retrieved.
default_meta_values
Title : default_meta_values
Usage : %values = $db->default_meta_values
Function: empty the database
Returns : a list of tag=>value pairs
Args : none
Status : protected
This method returns a list of tag=>value pairs that contain default meta information about
the database. It is invoked by initialize() to write out the default meta values. The
base class version returns an empty list.
For things to work properly, meta value names must be UPPERCASE.
get_features_iterator
Title : get_features_iterator
Usage : $iterator = $db->get_features_iterator($search,$options,$callback)
Function: create an iterator on a features() query
Returns : A Bio::DB::GFF::Adaptor::dbi::iterator object
Args : see get_features()
Status : public
This method is similar to get_features(), except that it returns an iterator across the
query. See Bio::DB::GFF::Adaptor::dbi::iterator.
do_initialize
Title : do_initialize
Usage : $success = $db->do_initialize($drop_all)
Function: initialize the database
Returns : a boolean indicating the success of the operation
Args : a boolean indicating whether to delete existing data
Status : protected
This method will load the schema into the database. If $drop_all is true, then any
existing data in the tables known to the schema will be deleted.
Internally, this method calls schema() to get the schema data.
finish_load
Title : finish_load
Usage : $db->finish_load
Function: called after load_gff_line()
Returns : number of records loaded
Args : none
Status : protected
This method performs schema-specific cleanup after loading a set of GFF records. It
finishes each of the statement handlers prepared by setup_load().
create_other_schema_objects
Title : create_other_schema_objects
Usage : $self->create_other_schema_objects($table_name)
Function: create other schema objects like : indexes, sequences, triggers
Returns :
Args :
Status : Abstract
drop_all
Title : drop_all
Usage : $db->drop_all
Function: empty the database
Returns : void
Args : none
Status : protected
This method drops the tables known to this module. Internally it calls the abstract
tables() method.
clone
The clone() method should be used when you want to pass the Bio::DB::GFF object to a child
process across a fork(). The child must call clone() before making any queries.
This method does two things: (1) it sets the underlying database handle's InactiveDestroy
parameter to 1, thereby preventing the database connection from being destroyed in the
parent when the dbh's destructor is called; (2) it replaces the dbh with the result of
dbh->clone(), so that we now have an independent handle.
QUERIES TO IMPLEMENT
The following astract methods either return DBI statement handles or fragments of SQL.
They must be implemented by subclasses of this module. See
Bio::DB::GFF::Adaptor::dbi::mysql for examples.
drop_other_schema_objects
Title : drop_other_schema_objects
Usage : $self->create_other_schema_objects($table_name)
Function: create other schema objects like : indexes, sequences, triggers
Returns :
Args :
Status : Abstract
make_features_select_part
Title : make_features_select_part
Usage : $string = $db->make_features_select_part()
Function: make select part of the features query
Returns : a string
Args : none
Status : Abstract
This abstract method creates the part of the features query that immediately follows the
SELECT keyword.
tables
Title : tables
Usage : @tables = $db->tables
Function: return list of tables that belong to this module
Returns : list of tables
Args : none
Status : protected
This method lists the tables known to the module.
schema
Title : schema
Usage : $schema = $db->schema
Function: return the CREATE script for the schema
Returns : a hashref
Args : none
Status : abstract
This method returns an array ref containing the various CREATE statements needed to
initialize the database tables. The keys are the table names, and the values are strings
containing the appropriate CREATE statement.
DESTROY
Title : DESTROY
Usage : $db->DESTROY
Function: disconnect database at destruct time
Returns : void
Args : none
Status : protected
This is the destructor for the class.
make_features_by_name_where_part
Title : make_features_by_name_where_part
Usage : $db->make_features_by_name_where_part
Function: create the SQL fragment needed to select a feature by its group name & class
Returns : a SQL fragment and bind arguments
Args : see below
Status : Protected
make_features_by_id_where_part
Title : make_features_by_id_where_part
Usage : $db->make_features_by_id_where_part($ids)
Function: create the SQL fragment needed to select a set of features by their ids
Returns : a SQL fragment and bind arguments
Args : arrayref of IDs
Status : Protected
make_features_by_gid_where_part
Title : make_features_by_id_where_part
Usage : $db->make_features_by_gid_where_part($ids)
Function: create the SQL fragment needed to select a set of features by their ids
Returns : a SQL fragment and bind arguments
Args : arrayref of IDs
Status : Protected
make_features_from_part
Title : make_features_from_part
Usage : $string = $db->make_features_from_part()
Function: make from part of the features query
Returns : a string
Args : none
Status : protected
This method creates the part of the features query that immediately follows the FROM
keyword.
make_features_join_part
Title : make_features_join_part
Usage : $string = $db->make_features_join_part()
Function: make join part of the features query
Returns : a string
Args : none
Status : protected
This method creates the part of the features query that immediately follows the WHERE
keyword.
make_features_order_by_part
Title : make_features_order_by_part
Usage : ($query,@args) = $db->make_features_order_by_part()
Function: make the ORDER BY part of the features() query
Returns : a SQL fragment and bind arguments, if any
Args : none
Status : protected
This method creates the part of the features query that immediately follows the ORDER BY
part of the query issued by features() and related methods.
make_features_group_by_part
Title : make_features_group_by_part
Usage : ($query,@args) = $db->make_features_group_by_part()
Function: make the GROUP BY part of the features() query
Returns : a SQL fragment and bind arguments, if any
Args : none
Status : protected
This method creates the part of the features query that immediately follows the GROUP BY
part of the query issued by features() and related methods.
refseq_query
Title : refseq_query
Usage : ($query,@args) = $db->refseq_query($name,$class)
Function: create SQL fragment that selects the desired reference sequence
Returns : a list containing the query and bind arguments
Args : reference sequence name and class
Status : protected
This method is called by make_features_by_range_where_part() to construct the part of the
select WHERE section that selects a particular reference sequence. It returns a mult-
element list in which the first element is the SQL fragment and subsequent elements are
bind values.
For example:
sub refseq_query {
my ($name,$class) = @_;
return ('gff.refseq=? AND gff.refclass=?',
$name,$class);
}
The current schema does not distinguish among different classes of reference sequence.
attributes
Title : attributes
Usage : @attributes = $db->attributes($id,$name)
Function: get the attributes on a particular feature
Returns : an array of string
Args : feature ID
Status : public
Some GFF version 2 files use the groups column to store a series of attribute/value pairs.
In this interpretation of GFF, the first such pair is treated as the primary group for the
feature; subsequent pairs are treated as attributes. Two attributes have special meaning:
"Note" is for backward compatibility and is used for unstructured text remarks. "Alias"
is considered as a synonym for the feature name.
If no name is provided, then attributes() returns a flattened hash, of attribute=>value
pairs. This lets you do:
%attributes = $db->attributes($id);
Normally, attributes() will be called by the feature:
@notes = $feature->attributes('Note');
overlap_query_nobin
Title : overlap_query
Usage : ($query,@args) = $db->overlap_query($start,$stop)
Function: create SQL fragment that selects the desired features by range
Returns : a list containing the query and bind arguments
Args : the start and stop of a range, inclusive
Status : protected
This method is called by make_features_byrange_where_part() to construct the part of the
select WHERE section that selects a set of features that overlap a range. It returns a
multi-element list in which the first element is the SQL fragment and subsequent elements
are bind values.
sub overlap_query_nobin {
my ($start,$stop) = @_;
return ('gff.stop>=? AND gff.start<=?', $start,$stop);
contains_query_nobin
Title : contains_query
Usage : ($query,@args) = $db->contains_query_nobin($start,$stop)
Function: create SQL fragment that selects the desired features by range
Returns : a list containing the query and bind arguments
Args : the start and stop of a range, inclusive
Status : protected
This method is called by make_features_byrange_where_part() to construct the part of the
select WHERE section that selects a set of features entirely enclosed by a range. It
returns a multi-element list in which the first element is the SQL fragment and subsequent
elements are bind values. For example:
sub contains_query_nobin {
my ($start,$stop) = @_;
return ('gff.start>=? AND gff.stop<=?',
$start,$stop);
contained_in_query_nobin
Title : contained_in_query_nobin
Usage : ($query,@args) = $db->contained_in_query($start,$stop)
Function: create SQL fragment that selects the desired features by range
Returns : a list containing the query and bind arguments
Args : the start and stop of a range, inclusive
Status : protected
This method is called by make_features_byrange_where_part() to construct the part of the
select WHERE section that selects a set of features entirely enclosed by a range. It
returns a multi-element list in which the first element is the SQL fragment and subsequent
elements are bind values.For example:
sub contained_in_query_nobin {
my ($start,$stop) = @_;
return ('gff.start<=? AND gff.stop>=?',
$start,$stop);
}
types_query
Title : types_query
Usage : ($query,@args) = $db->types_query($types)
Function: create SQL fragment that selects the desired features by type
Returns : a list containing the query and bind arguments
Args : an array reference containing the types
Status : protected
This method is called by make_features_byrange_where_part() to construct the part of the
select WHERE section that selects a set of features based on their type. It returns a
multi-element list in which the first element is the SQL fragment and subsequent elements
are bind values. The argument is an array reference containing zero or more
[$method,$source] pairs.
make_types_select_part
Title : make_types_select_part
Usage : ($string,@args) = $db->make_types_select_part(@args)
Function: create the select portion of the SQL for fetching features type list
Returns : query string and bind arguments
Args : see below
Status : protected
This method is called by get_types() to generate the query fragment and bind arguments for
the SELECT part of the query that retrieves lists of feature types. The four positional
arguments are as follows:
$refseq reference sequence name
$start start of region
$stop end of region
$want_count true to return the count of this feature type
If $want_count is false, the SQL fragment returned must produce a list of feature types in
the format (method, source).
If $want_count is true, the returned fragment must produce a list of feature types in the
format (method, source, count).
make_types_from_part
Title : make_types_from_part
Usage : ($string,@args) = $db->make_types_from_part(@args)
Function: create the FROM portion of the SQL for fetching features type lists
Returns : query string and bind arguments
Args : see below
Status : protected
This method is called by get_types() to generate the query fragment and bind arguments for
the FROM part of the query that retrieves lists of feature types. The four positional
arguments are as follows:
$refseq reference sequence name
$start start of region
$stop end of region
$want_count true to return the count of this feature type
If $want_count is false, the SQL fragment returned must produce a list of feature types in
the format (method, source).
If $want_count is true, the returned fragment must produce a list of feature types in the
format (method, source, count).
make_types_join_part
Title : make_types_join_part
Usage : ($string,@args) = $db->make_types_join_part(@args)
Function: create the JOIN portion of the SQL for fetching features type lists
Returns : query string and bind arguments
Args : see below
Status : protected
This method is called by get_types() to generate the query fragment and bind arguments for
the JOIN part of the query that retrieves lists of feature types. The four positional
arguments are as follows:
$refseq reference sequence name
$start start of region
$stop end of region
$want_count true to return the count of this feature type
make_types_where_part
Title : make_types_where_part
Usage : ($string,@args) = $db->make_types_where_part(@args)
Function: create the WHERE portion of the SQL for fetching features type lists
Returns : query string and bind arguments
Args : see below
Status : protected
This method is called by get_types() to generate the query fragment and bind arguments for
the WHERE part of the query that retrieves lists of feature types. The four positional
arguments are as follows:
$refseq reference sequence name
$start start of region
$stop end of region
$want_count true to return the count of this feature type
make_types_group_part
Title : make_types_group_part
Usage : ($string,@args) = $db->make_types_group_part(@args)
Function: create the GROUP BY portion of the SQL for fetching features type lists
Returns : query string and bind arguments
Args : see below
Status : protected
This method is called by get_types() to generate the query fragment and bind arguments for
the GROUP BY part of the query that retrieves lists of feature types. The four positional
arguments are as follows:
$refseq reference sequence name
$start start of region
$stop end of region
$want_count true to return the count of this feature type
get_feature_id
Title : get_feature_id
Usage : $integer = $db->get_feature_id($ref,$start,$stop,$typeid,$groupid)
Function: get the ID of a feature
Returns : an integer ID or undef
Args : none
Status : private
This internal method is called by load_gff_line to look up the integer ID of an existing
feature. It is ony needed when replacing a feature with new information.
make_abscoord_query
Title : make_abscoord_query
Usage : $sth = $db->make_abscoord_query($name,$class);
Function: create query that finds the reference sequence coordinates given a landmark & classa
Returns : a DBI statement handle
Args : name and class of landmark
Status : protected
The statement handler should return rows containing five fields:
1. reference sequence name
2. reference sequence class
3. start position
4. stop position
5. strand ("+" or "-")
This query always returns "Sequence" as the class of the reference sequence.
feature_summary
Title : feature_summary
Usage : $summary = $db->feature_summary(@args)
Function: returns a coverage summary across indicated region/type
Returns : a Bio::SeqFeatureI object containing the "coverage" tag
Args : see below
Status : public
This method is used to get coverage density information across a region of interest. You
provide it with a region of interest, optional a list of feature types, and a count of the
number of bins over which you want to calculate the coverage density. An object is
returned corresponding to the requested region. It contains a tag called "coverage" that
will return an array ref of "bins" length. Each element of the array describes the number
of features that overlap the bin at this position.
Arguments:
Argument Description
-------- -----------
-seq_id Sequence ID for the region
-start Start of region
-end End of region
-type/-types Feature type of interest or array ref of types
-bins Number of bins across region. Defaults to 1000.
-iterator Return an iterator across the region
Note that this method uses an approximate algorithm that is only accurate to 500 bp, so
when dealing with bins that are smaller than 1000 bp, you may see some shifting of counts
between adjacent bins.
Although an -iterator option is provided, the method only ever returns a single feature,
so this is fairly useless.
coverage_array
Title : coverage_array
Usage : $arrayref = $db->coverage_array(@args)
Function: returns a coverage summary across indicated region/type
Returns : an array reference
Args : see below
Status : public
This method is used to get coverage density information across a region of interest. The
arguments are identical to feature_summary, except that instead of returning a
Bio::SeqFeatureI object, it returns an array reference of the desired number of bins. The
value of each element corresponds to the number of features in the bin.
Arguments:
Argument Description
-------- -----------
-seq_id Sequence ID for the region
-start Start of region
-end End of region
-type/-types Feature type of interest or array ref of types
-bins Number of bins across region. Defaults to 1000.
Note that this method uses an approximate algorithm that is only accurate to 500 bp, so
when dealing with bins that are smaller than 1000 bp, you may see some shifting of counts
between adjacent bins.
build_summary_statistics
Title : build_summary_statistics
Usage : $db->build_summary_statistics
Function: prepares the table needed to call feature_summary()
Returns : nothing
Args : none
Status : public
This method is used to build the summary statistics table that is used by the
feature_summary() and coverage_array() methods. It needs to be called whenever the
database is updated.
BUGS
Schemas need work to support multiple hierarchical groups.
SEE ALSO
Bio::DB::GFF, bioperl
AUTHOR
Lincoln Stein <lstein@cshl.org>.
Copyright (c) 2001 Cold Spring Harbor Laboratory.
This library is free software; you can redistribute it and/or modify it under the same
terms as Perl itself.