NAME¶
Bio::FeatureIO::gff - read/write GFF feature files
SYNOPSIS¶
my $feature; #get a Bio::SeqFeature::Annotated somehow
my $featureOut = Bio::FeatureIO->new(
-format => 'gff',
-version => 3,
-fh => \*STDOUT,
-validate_terms => 1, #boolean. validate ontology terms online? default 0 (false).
);
$featureOut->write_feature($feature);
DESCRIPTION¶
Currently implemented:
version read? write?
------------------------------
GFF 1 N N
GFF 2 N N
GFF 2.5 (GTF) N Y
GFF 3 Y Y
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_list - 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://redmine.open-bio.org/projects/bioperl/
AUTHOR¶
Allen Day, <allenday@ucla.edu>
CONTRIBUTORS¶
Steffen Grossmann, <grossman@molgen.mpg.de>
Scott Cain, <scain@cpan.org>
Rob Edwards <rob@salmonella.org>
APPENDIX¶
The rest of the documentation details each of the object methods. Internal
methods are usually preceded with a _
next_feature()¶
Usage : my $feature = $featureio->next_feature();
Function: reads a feature record from a GFF stream and returns it as an object.
Returns : a Bio::SeqFeature::Annotated object
Args : N/A
next_feature_group¶
Title : next_feature_group
Usage : @feature_group = $stream->next_feature_group
Function: Reads the next feature_group from $stream and returns it.
Feature groups in GFF3 files are separated by '###' directives. The
features in a group might form a hierarchical structure. The
complete hierarchy of features is returned, i.e. the returned array
represents only the top-level features. Lower-level features can
be accessed using the 'get_SeqFeatures' method recursively.
Example : # getting the complete hierarchy of features in a GFF3 file
my @toplevel_features;
while (my @fg = $stream->next_feature_group) {
push(@toplevel_features, @fg);
}
Returns : an array of Bio::SeqFeature::Annotated objects
Args : none
next_seq()¶
access the FASTA section (if any) at the end of the GFF stream. note that this
method will return undef if not all features in the stream have been handled
write_feature()¶
Usage : $featureio->write_feature( Bio::SeqFeature::Annotated->new(...) );
Function: writes a feature in GFF format. the GFF version used is governed by the
'-version' argument passed to Bio::FeatureIO->new(), and defaults to GFF
version 3.
Returns : ###FIXME
Args : a Bio::SeqFeature::Annotated object.
ACCESSORS¶
fasta_mode()¶
Usage : $obj->fasta_mode($newval)
Function:
Example :
Returns : value of fasta_mode (a scalar)
Args : on set, new value (a scalar or undef, optional)
Side effect when setting: rewind the file handle a little bit to get the last
carriage return that was swallowed when the previous line was processed.
seqio()¶
Usage : $obj->seqio($newval)
Function: holds a Bio::SeqIO instance for handling the GFF3 ##FASTA section.
Returns : value of seqio (a scalar)
Args : on set, new value (a scalar or undef, optional)
sequence_region()¶
Usage :
Function: ###FIXME
Returns :
Args :
so()¶
Usage : $obj->so($newval)
Function: holds a Sequence Ontology instance
Returns : value of so (a scalar)
Args : on set, new value (a scalar or undef, optional)
validate()¶
Usage : $obj->validate($newval)
Function: true if encountered ontology terms in next_feature()
mode should be validated.
Returns : value of validate (a scalar)
Args : on set, new value (a scalar or undef, optional)
version()¶
Usage : $obj->version($newval)
Function: version of GFF to read/write. valid values are 1, 2, 2.5, and 3.
Returns : value of version (a scalar)
Args : on set, new value (a scalar or undef, optional)
INTERNAL METHODS¶
_buffer_feature()¶
Usage :
Function: ###FIXME
Returns :
Args :
ignore_seq_region¶
Set this flag to keep FeatureIO from returning a feature for a ##sequence-region
directive
_handle_directive()¶
this method is called for lines beginning with '##'.
_handle_feature()¶
this method is called for each line not beginning with '#'. it parses the line
and returns a Bio::SeqFeature::Annotated object.
_handle_non_reserved_tag()¶
Usage : $self->_handle_non_reserved_tag($feature,$tag,$value)
Function: Deal with non-reserved word tags in the ninth column
Returns : An updated Bio::SeqFeature::Annotated object
Args : A Bio::SeqFeature::Annotated and a tag/value pair
Note that this method can be overridden in a subclass to provide special
handling of non-reserved word tags.
organims¶
Gets/sets the organims from the organism directive
_write_feature_1()¶
write a feature in GFF v1 format. currently not implemented.
_write_feature_2()¶
write a feature in GFF v2 format. currently not implemented.
_write_feature_25()¶
write a feature in GFF v2.5 (aka GTF) format.
_write_feature_3()¶
write a feature in GFF v3 format.