Ace::Sequence::FeatureList(3pm) 			User Contributed Perl Documentation			   Ace::Sequence::FeatureList(3pm)

NAME

       Ace::Sequence::FeatureList - Lightweight Access to Features

SYNOPSIS

	   # get a megabase from the middle of chromosome I
	   $seq = Ace::Sequence->new(-name   => 'CHROMOSOME_I,
				     -db     => $db,
				     -offset => 3_000_000,
				     -length => 1_000_000);

	   # find out what's there
	   $list = $seq->feature_list;

	   # Scalar context: count all the features
	   $feature_count = $list->types;

	   # Array context: list all the feature types
	   @feature_types = $list->types;

	   # Scalar context, 1 argument.  Count this type
	   $gene_cnt = $list->types('Predicted_gene');
	   print "There are $gene_cnt genes here.
";

	   # Array context, 1 argument.  Get list of subtypes
	   @subtypes = $list->types('Predicted_gene');

	   # Two arguments. Count type & subtype
	   $genefinder_cnt = $list->types('Predicted_gene','genefinder');

DESCRIPTION

       Ace::Sequence::FeatureList is a small class that provides statistical information about sequence features.  From it you can obtain summary
       counts of the features and their types within a selected region.

OBJECT CREATION

       You will not ordinarily create an Ace::Sequence::FeatureList object directly.  Instead, objects will be created by calling a Ace::Sequence
       object's feature_list() method.	If you wish to create an Ace::Sequence::FeatureList object directly, please consult the source code for
       the new() method.

OBJECT METHODS

       There are only two methods in Ace::Sequence::FeatureList.

       type()
	   This method has five distinct behaviors, depending on its context and the number of parameters.  Usage should be intuitive

	    Context	  Arguments	  Behavior
	    -------	  ---------	  --------

	    scalar	   -none-	  total count of features in list
	    array	   -none-	  list feature types (e.g. "exon")
	    scalar	    type	  count features of this type
	    array	    type	  list subtypes of this type
	    -any-	type,subtype	  count features of this type & subtype

	   For example, this code fragment will count the number of exons present on the list:

	     $exon_count = $list->type('exon');

	   This code fragment will count the number of exons found by "genefinder":

	     $predicted_exon_count = $list->type('exon','genefinder');

	   This code fragment will print out all subtypes of "exon" and their counts:

	     for my $subtype ($list->type('exon')) {
		 print $subtype,"	",$list->type('exon',$subtype),"
";
	     }

       asString()
	     print $list->asString;

	   This dumps the list out in tab-delimited format.  The order of columns is type, subtype, count.

SEE ALSO

       Ace, Ace::Object, Ace::Sequence, Ace::Sequence::Feature, GFF

AUTHOR

       Lincoln Stein <lstein@w3.org> with extensive help from Jean Thierry-Mieg <mieg@kaa.crbm.cnrs-mop.fr>

       Copyright (c) 1999, Lincoln D. Stein

       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.

perl v5.14.2							    2000-06-11					   Ace::Sequence::FeatureList(3pm)