Provided by: libbio-graphics-perl_2.40-6_all 
NAME
Bio::Graphics::Feature - A simple feature object for use with Bio::Graphics::Panel
SYNOPSIS
use Bio::Graphics::Feature;
# create a simple feature with no internal structure
$f = Bio::Graphics::Feature->new(-start => 1000,
-stop => 2000,
-type => 'transcript',
-name => 'alpha-1 antitrypsin',
-desc => 'an enzyme inhibitor',
);
# create a feature composed of multiple segments, all of type "similarity"
$f = Bio::Graphics::Feature->new(-segments => [[1000,1100],[1500,1550],[1800,2000]],
-name => 'ABC-3',
-type => 'gapped_alignment',
-subtype => 'similarity');
# build up a gene exon by exon
$e1 = Bio::Graphics::Feature->new(-start=>1,-stop=>100,-type=>'exon');
$e2 = Bio::Graphics::Feature->new(-start=>150,-stop=>200,-type=>'exon');
$e3 = Bio::Graphics::Feature->new(-start=>300,-stop=>500,-type=>'exon');
$f = Bio::Graphics::Feature->new(-segments=>[$e1,$e2,$e3],-type=>'gene');
DESCRIPTION
This is a simple Bio::SeqFeatureI-compliant object that is compatible with
Bio::Graphics::Panel. With it you can create lightweight feature objects for drawing.
All methods are as described in Bio::SeqFeatureI with the following additions:
The new() Constructor
$feature = Bio::Graphics::Feature->new(@args);
This method creates a new feature object. You can create a simple feature that contains
no subfeatures, or a hierarchically nested object.
Arguments are as follows:
-seq_id the reference sequence
-start the start position of the feature
-end the stop position of the feature
-stop an alias for end
-name the feature name (returned by seqname())
-type the feature type (returned by primary_tag())
-primary_tag the same as -type
-source the source tag
-score the feature score (for GFF compatibility)
-desc a description of the feature
-segments a list of subfeatures (see below)
-subtype the type to use when creating subfeatures
-strand the strand of the feature (one of -1, 0 or +1)
-phase the phase of the feature (0..2)
-id an alias for -name
-seqname an alias for -name
-display_id an alias for -name
-display_name an alias for -name (do you get the idea the API has changed?)
-primary_id unique database ID
-url a URL to link to when rendered with Bio::Graphics
-configurator an object (like a Bio::Graphics::FeatureFile) that knows how
to configure the graphical representation of the object based
on its type.
-attributes a hashref of tag value attributes, in which the key is the tag
and the value is an array reference of values
-factory a reference to a feature factory, used for compatibility with
more obscure parts of Bio::DB::GFF
The subfeatures passed in -segments may be an array of Bio::Graphics::Feature objects, or
an array of [$start,$stop] pairs. Each pair should be a two-element array reference. In
the latter case, the feature type passed in -subtype will be used when creating the
subfeatures.
If no feature type is passed, then it defaults to "feature".
Non-SeqFeatureI methods
A number of new methods are provided for compatibility with Ace::Sequence, which has a
slightly different API from SeqFeatureI:
attributes()
An alternative interface to get_tag_values. Pass the name of an attribute to get the
value(s) of that attribute:
$expression_level = $gene->attributes('expression');
Call attributes() without any arguments to get a hash of all attributes:
%attributes = $gene->attributes;
url()
Get/set the URL that the graphical rendering of this feature will link to.
add_segment(@segments)
Add one or more segments (a subfeature). Segments can either be Feature objects, or
[start,stop] arrays, as in the -segments argument to new(). The feature endpoints are
automatically adjusted.
my @features = get_SeqFeatures('type1','type2','type3'...)
Get the subfeatures of this feature. If an optional list of types is provided, then
only returns subfeatures with the indicated primary_tag. (This is an extension of the
Bio::SeqFeatureI interface).
$feature->add_hit($hit)
For nucleotide alignments, add a feature that is a "hit" on the feature.
$hit = $feature->hit
Return the hit.
segments()
An alias for get_SeqFeatures().
get_all_SeqFeatures()
Alias for get_SeqFeatures()
merged_segments()
Another alias for sub_SeqFeature().
stop()
An alias for end().
name()
An alias for seqname().
exons()
An alias for sub_SeqFeature() (you don't want to know why!)
configurator()
Get/set the configurator that knows how to adjust the graphical representation of this
feature based on its type. Currently the only configurator that will work is
Bio::Graphics::FeatureFile.
factory
Title : factory
Usage : $factory = $obj->factory([$new_factory])
Function: Returns the feature factory from which this feature was generated.
Mostly for compatibility with weird dependencies in gbrowse.
Returns : A feature factory
Args : None
display_name
Title : display_name
Usage : $id = $obj->display_name or $obj->display_name($newid);
Function: Gets or sets the display id, also known as the common name of
the Seq object.
The semantics of this is that it is the most likely string
to be used as an identifier of the sequence, and likely to
have "human" readability. The id is equivalent to the LOCUS
field of the GenBank/EMBL databanks and the ID field of the
Swissprot/sptrembl database. In fasta format, the >(\S+) is
presumed to be the id, though some people overload the id
to embed other information. Bioperl does not use any
embedded information in the ID field, and people are
encouraged to use other mechanisms (accession field for
example, or extending the sequence object) to solve this.
Notice that $seq->id() maps to this function, mainly for
legacy/convenience issues.
Returns : A string
Args : None or a new id
accession_number
Title : accession_number
Usage : $unique_biological_key = $obj->accession_number;
Function: Returns the unique biological id for a sequence, commonly
called the accession_number. For sequences from established
databases, the implementors should try to use the correct
accession number. Notice that primary_id() provides the
unique id for the implementation, allowing multiple objects
to have the same accession number in a particular implementation.
For sequences with no accession number, this method should return
"unknown".
Returns : A string
Args : None
alphabet
Title : alphabet
Usage : if( $obj->alphabet eq 'dna' ) { /Do Something/ }
Function: Returns the type of sequence being one of
'dna', 'rna' or 'protein'. This is case sensitive.
This is not called <type> because this would cause
upgrade problems from the 0.5 and earlier Seq objects.
Returns : a string either 'dna','rna','protein'. NB - the object must
make a call of the type - if there is no type specified it
has to guess.
Args : none
Status : Virtual
desc
Title : desc
Usage : $seqobj->desc($string) or $seqobj->desc()
Function: Sets or gets the description of the sequence
Example :
Returns : The description
Args : The description or none
location
Title : location
Usage : my $location = $seqfeature->location()
Function: returns a location object suitable for identifying location
of feature on sequence or parent feature
Returns : Bio::LocationI object
Args : none
location_string
Title : location_string
Usage : my $string = $seqfeature->location_string()
Function: Returns a location string in a format recognized by gbrowse
Returns : a string
Args : none
This is a convenience function used by the generic genome browser. It returns the location
of the feature and its subfeatures in the compact form "start1..end1,start2..end2,...".
Use $seqfeature->location()->toFTString() to obtain a standard GenBank/EMBL location
representation.
configurator
Title : configurator
Usage : my $configurator = $seqfeature->configurator([$new_configurator])
Function: Get/set an object that provides configuration information for this feature
Returns : configurator object
Args : new configurator object (optional)
A configurator object provides hints to the Bio::Graphics::Feature as to how to display
itself on a canvas. Currently this stores the Bio::Graphics::FeatureFile and descendents.
url
Title : url
Usage : my $url = $seqfeature->url([$new_url])
Function: Get/set the URL associated with this feature
Returns : a URL string
Args : new URL (optional)
Features link to URLs when displayed as a clickable image map. This field holds that
information.
make_link
Title : make_link
Usage : my $url = $seqfeature->make_link()
Function: Create a URL for the feature
Returns : a URL string
Args : none
This method will invoke the configurator in order to turn the feature into a link. Used by
Bio::Graphics::Panel to create imagemaps.
SEE ALSO
Bio::Graphics::Panel,Bio::Graphics::Glyph, Bio::Graphics::FeatureBase GD
AUTHOR
Lincoln Stein <lstein@cshl.edu>.
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. See DISCLAIMER.txt for disclaimers of warranty.