++ed by:
DEMIAN GENEHACK POTATOGIM FARACO MAJENSEN

9 PAUSE users
13 non-PAUSE users.

Christopher Fields
and 1 contributors

NAME

Bio::SimpleAlign - Multiple alignments held as a set of sequences

SYNOPSIS

  # Use Bio::AlignIO to read in the alignment
  $str = Bio::AlignIO->new(-file => 't/data/testaln.pfam');
  $aln = $str->next_aln();

  # Describe
  print $aln->length;
  print $aln->no_residues;
  print $aln->is_flush;
  print $aln->no_sequences;
  print $aln->score;
  print $aln->percentage_identity;
  print $aln->consensus_string(50);

  # Find the position in the alignment for a sequence location
  $pos = $aln->column_from_residue_number('1433_LYCES', 14); # = 6;

  # Extract sequences and check values for the alignment column $pos
  foreach $seq ($aln->each_seq) {
      $res = $seq->subseq($pos, $pos);
      $count{$res}++;
  }
  foreach $res (keys %count) {
      printf "Res: %s  Count: %2d\n", $res, $count{$res};
  }

  # Manipulate
  $aln->remove_seq($seq);
  $mini_aln = $aln->slice(20,30);  # get a block of columns
  $mini_aln = $aln->select_noncont(1,3,5,7,11); # get single columns
  $new_aln = $aln->remove_columns([20,30]); # remove by position
  $new_aln = $aln->remove_columns(['mismatch']); # remove by property

  # Analyze
  $str = $aln->consensus_string($threshold_percent);
  $str = $aln->match_line();
  $str = $aln->cigar_line();
  $id = $aln->percentage_identity;

  # See the module documentation for details and more methods.

DESCRIPTION

SimpleAlign is an object that handles a multiple sequence alignment (MSA). It is very permissive of types (it does not insist on sequences being all same length, for example). Think of it as a set of sequences with a whole series of built-in manipulations and methods for reading and writing alignments.

SimpleAlign uses Bio::LocatableSeq, a subclass of Bio::PrimarySeq, to store its sequences. These are subsequences with a start and end positions in the parent reference sequence. Each sequence in the SimpleAlign object is a Bio::LocatableSeq.

SimpleAlign expects the combination of name, start, and end for a given sequence to be unique in the alignment, and this is the key for the internal hashes (name, start, end are abbreviated nse in the code). However, in some cases people do not want the name/start-end to be displayed: either multiple names in an alignment or names specific to the alignment (ROA1_HUMAN_1, ROA1_HUMAN_2 etc). These names are called displayname, and generally is what is used to print out the alignment. They default to name/start-end.

The SimpleAlign Module is derived from the Align module by Ewan Birney.

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 one of the Bioperl mailing lists. Your participation is much appreciated.

  bioperl-l@bioperl.org                  - General discussion
  http://bioperl.org/wiki/Mailing_lists  - About the mailing lists

Reporting Bugs

Report bugs to the Bioperl bug tracking system to help us keep track the bugs and their resolution. Bug reports can be submitted via the web:

  http://bugzilla.open-bio.org/

AUTHOR

Ewan Birney, birney@ebi.ac.uk

CONTRIBUTORS

Allen Day, allenday-at-ucla.edu, Richard Adams, Richard.Adams-at-ed.ac.uk, David J. Evans, David.Evans-at-vir.gla.ac.uk, Heikki Lehvaslaiho, heikki-at-bioperl-dot-org, Allen Smith, allens-at-cpan.org, Jason Stajich, jason-at-bioperl.org, Anthony Underwood, aunderwood-at-phls.org.uk, Xintao Wei & Giri Narasimhan, giri-at-cs.fiu.edu Brian Osborne, bosborne at alum.mit.edu Weigang Qiu, Weigang at GENECTR-HUNTER-CUNY-EDU Hongyu Zhang, forward at hongyu.org

SEE ALSO

Bio::LocatableSeq

APPENDIX

The rest of the documentation details each of the object methods. Internal methods are usually preceded with a _

new

 Title     : new
 Usage     : my $aln = Bio::SimpleAlign->new();
 Function  : Creates a new simple align object
 Returns   : Bio::SimpleAlign
 Args      : -source     => string representing the source program
                            where this alignment came from
             -annotation => Bio::AnnotationCollectionI
             -seq_annotation => Bio::AnnotationCollectionI for sequences (requires -annotation also be set)
             -seqs       => array ref containing Bio::LocatableSeq or Bio::Seq::Meta
             -consensus  => consensus string
             -consensus_meta  => Bio::Seq::Meta object containing consensus met information (kludge)

Modifier methods

These methods modify the MSA by adding, removing or shuffling complete sequences.

add_seq

 Title     : add_seq
 Usage     : $myalign->add_seq($newseq);
 Function  : Adds another sequence to the alignment. *Does not* align
             it - just adds it to the hashes.
 Returns   : nothing
 Args      : a Bio::LocatableSeq object
             order (optional)

See Bio::LocatableSeq for more information

remove_seq

 Title     : remove_seq
 Usage     : $aln->remove_seq($seq);
 Function  : Removes a single sequence from an alignment
 Returns   :
 Argument  : a Bio::LocatableSeq object

purge

 Title   : purge
 Usage   : $aln->purge(0.7);
 Function: Removes sequences above given sequence similarity
           This function will grind on large alignments. Beware!
 Example :
 Returns : An array of the removed sequences
 Args    : float, threshold for similarity

sort_alphabetically

 Title     : sort_alphabetically
 Usage     : $ali->sort_alphabetically
 Function  : Changes the order of the alignment to alphabetical on name
             followed by numerical by number.
 Returns   :
 Argument  :

sort_by_list

 Title     : sort_by_list
 Usage     : $aln_ordered=$aln->sort_by_list($list_file)
 Function  : Arbitrarily order sequences in an alignment
 Returns   : A new Bio::SimpleAlign object
 Argument  : a file listing sequence names in intended order (one name per line)

set_new_reference

 Title     : set_new_reference
 Usage     : $aln->set_new_reference(3 or 'B31'):  Select the 3rd sequence, or
             the sequence whoes name is "B31" (full, exact, and case-sensitive),
             as the reference (1st) sequence
 Function  : Change/Set a new reference (i.e., the first) sequence
 Returns   : a new Bio::SimpleAlign object.
             Throws an exception if designated sequence not found
 Argument  : a positive integer of sequence order, or a sequence name
             in the original alignment

uniq_seq

 Title     : uniq_seq
 Usage     : $aln->uniq_seq():  Remove identical sequences in
             in the alignment.  Ambiguous base ("N", "n") and
             leading and ending gaps ("-") are NOT counted as
             differences.
 Function  : Make a new alignment of unique sequence types (STs)
 Returns   : 1. a new Bio::SimpleAlign object (all sequences renamed as "ST")
             2. ST of each sequence in STDERR
 Argument  : None

Sequence selection methods

Methods returning one or more sequences objects.

each_seq

 Title     : each_seq
 Usage     : foreach $seq ( $align->each_seq() )
 Function  : Gets a Seq object from the alignment
 Returns   : Seq object
 Argument  :

each_alphabetically

 Title     : each_alphabetically
 Usage     : foreach $seq ( $ali->each_alphabetically() )
 Function  : Returns a sequence object, but the objects are returned
             in alphabetically sorted order.
             Does not change the order of the alignment.
 Returns   : Seq object
 Argument  :

each_seq_with_id

 Title     : each_seq_with_id
 Usage     : foreach $seq ( $align->each_seq_with_id() )
 Function  : Gets a Seq objects from the alignment, the contents
             being those sequences with the given name (there may be
             more than one)
 Returns   : Seq object
 Argument  : a seq name

get_seq_by_pos

 Title     : get_seq_by_pos
 Usage     : $seq = $aln->get_seq_by_pos(3) # third sequence from the alignment
 Function  : Gets a sequence based on its position in the alignment.
             Numbering starts from 1.  Sequence positions larger than
             no_sequences() will thow an error.
 Returns   : a Bio::LocatableSeq object
 Args      : positive integer for the sequence position

get_seq_by_id

 Title     : get_seq_by_id
 Usage     : $seq = $aln->get_seq_by_id($name) # seq named $name
 Function  : Gets a sequence based on its name.
             Sequences that do not exist will warn and return undef
 Returns   : a Bio::LocatableSeq object
 Args      : string for sequence name

seq_with_features

 Title   : seq_with_features
 Usage   : $seq = $aln->seq_with_features(-pos => 1,
                                          -consensus => 60
                                          -mask =>
           sub { my $consensus = shift;

                 for my $i (1..5){
                    my $n = 'N' x $i;
                    my $q = '\?' x $i;
                    while($consensus =~ /[^?]$q[^?]/){
                       $consensus =~ s/([^?])$q([^?])/$1$n$2/;
                    }
                  }
                 return $consensus;
               }
                                         );
 Function: produces a Bio::Seq object by first splicing gaps from -pos
           (by means of a splice_by_seq_pos() call), then creating
           features using non-? chars (by means of a consensus_string()
           call with stringency -consensus).
 Returns : a Bio::Seq object
 Args    : -pos : required. sequence from which to build the Bio::Seq
             object
           -consensus : optional, defaults to consensus_string()'s
             default cutoff value
           -mask : optional, a coderef to apply to consensus_string()'s
             output before building features.  this may be useful for
             closing gaps of 1 bp by masking over them with N, for
             instance

Create new alignments

The result of these methods are horizontal or vertical subsets of the current MSA.

select

 Title     : select
 Usage     : $aln2 = $aln->select(1, 3) # three first sequences
 Function  : Creates a new alignment from a continuous subset of
             sequences.  Numbering starts from 1.  Sequence positions
             larger than no_sequences() will thow an error.
 Returns   : a Bio::SimpleAlign object
 Args      : positive integer for the first sequence
             positive integer for the last sequence to include (optional)

select_noncont

 Title     : select_noncont
 Usage     : # 1st and 3rd sequences, sorted
             $aln2 = $aln->select_noncont(1, 3)

             # 1st and 3rd sequences, sorted (same as first)
             $aln2 = $aln->select_noncont(3, 1)

             # 1st and 3rd sequences, unsorted
             $aln2 = $aln->select_noncont('nosort',3, 1)

 Function  : Creates a new alignment from a subset of sequences.  Numbering
             starts from 1.  Sequence positions larger than no_sequences() will
             throw an error.  Sorts the order added to new alignment by default,
             to prevent sorting pass 'nosort' as the first argument in the list.
 Returns   : a Bio::SimpleAlign object
 Args      : array of integers for the sequences.  If the string 'nosort' is
             passed as the first argument, the sequences will not be sorted
             in the new alignment but will appear in the order listed.

slice

 Title     : slice
 Usage     : $aln2 = $aln->slice(20,30)
 Function  : Creates a slice from the alignment inclusive of start and
             end columns, and the first column in the alignment is denoted 1.
             Sequences with no residues in the slice are excluded from the
             new alignment and a warning is printed. Slice beyond the length of
             the sequence does not do padding.
 Returns   : A Bio::SimpleAlign object
 Args      : Positive integer for start column, positive integer for end column,
             optional boolean which if true will keep gap-only columns in the newly
             created slice. Example:

             $aln2 = $aln->slice(20,30,1)

remove_columns

 Title     : remove_columns
 Usage     : $aln2 = $aln->remove_columns(['mismatch','weak']) or
             $aln2 = $aln->remove_columns([0,0],[6,8])
 Function  : Creates an aligment with columns removed corresponding to
             the specified type or by specifying the columns by number.
 Returns   : Bio::SimpleAlign object
 Args      : Array ref of types ('match'|'weak'|'strong'|'mismatch'|'gaps'|
             'all_gaps_columns') or array ref where the referenced array
             contains a pair of integers that specify a range.
             The first column is 0,

remove_gaps

 Title     : remove_gaps
 Usage     : $aln2 = $aln->remove_gaps
 Function  : Creates an aligment with gaps removed
 Returns   : a Bio::SimpleAlign object
 Args      : a gap character(optional) if none specified taken
                from $self->gap_char,
             [optional] $all_gaps_columns flag (1 or 0, default is 0)
                        indicates that only all-gaps columns should be deleted

Used from method remove_columns in most cases. Set gap character using gap_char().

Change sequences within the MSA

These methods affect characters in all sequences without changing the alignment.

splice_by_seq_pos

 Title   : splice_by_seq_pos
 Usage   : $status = splice_by_seq_pos(1);
 Function: splices all aligned sequences where the specified sequence
           has gaps.
 Example :
 Returns : 1 on success
 Args    : position of sequence to splice by

map_chars

 Title     : map_chars
 Usage     : $ali->map_chars('\.','-')
 Function  : Does a s/$arg1/$arg2/ on the sequences. Useful for gap
             characters

             Notice that the from (arg1) is interpretted as a regex,
             so be careful about quoting meta characters (eg
             $ali->map_chars('.','-') wont do what you want)
 Returns   :
 Argument  : 'from' rexexp
             'to' string

uppercase

 Title     : uppercase()
 Usage     : $ali->uppercase()
 Function  : Sets all the sequences to uppercase
 Returns   :
 Argument  :

cigar_line

 Title    : cigar_line()
 Usage    : %cigars = $align->cigar_line()
 Function : Generates a "cigar" (Compact Idiosyncratic Gapped Alignment
            Report) line for each sequence in the alignment. Examples are
            "1,60" or "5,10:12,58", where the numbers refer to conserved
            positions within the alignment. The keys of the hash are the
            NSEs (name/start/end) assigned to each sequence.
 Args     : threshold (optional, defaults to 100)
 Returns  : Hash of strings (cigar lines)

match_line

 Title    : match_line()
 Usage    : $line = $align->match_line()
 Function : Generates a match line - much like consensus string
            except that a line indicating the '*' for a match.
 Args     : (optional) Match line characters ('*' by default)
            (optional) Strong match char (':' by default)
            (optional) Weak match char ('.' by default)
 Returns  : String

gap_line

 Title    : gap_line()
 Usage    : $line = $align->gap_line()
 Function : Generates a gap line - much like consensus string
            except that a line where '-' represents gap
 Args     : (optional) gap line characters ('-' by default)
 Returns  : string

all_gap_line

 Title    : all_gap_line()
 Usage    : $line = $align->all_gap_line()
 Function : Generates a gap line - much like consensus string
            except that a line where '-' represents all-gap column
 Args     : (optional) gap line characters ('-' by default)
 Returns  : string

gap_col_matrix

 Title    : gap_col_matrix()
 Usage    : my $cols = $align->gap_col_matrix()
 Function : Generates an array of hashes where
            each entry in the array is a hash reference
            with keys of all the sequence names and
            and value of 1 or 0 if the sequence has a gap at that column
 Args     : (optional) gap line characters ($aln->gap_char or '-' by default)

match

 Title     : match()
 Usage     : $ali->match()
 Function  : Goes through all columns and changes residues that are
             identical to residue in first sequence to match '.'
             character. Sets match_char.

             USE WITH CARE: Most MSA formats do not support match
             characters in sequences, so this is mostly for output
             only. NEXUS format (Bio::AlignIO::nexus) can handle
             it.
 Returns   : 1
 Argument  : a match character, optional, defaults to '.'

unmatch

 Title     : unmatch()
 Usage     : $ali->unmatch()
 Function  : Undoes the effect of method match. Unsets match_char.
 Returns   : 1
 Argument  : a match character, optional, defaults to '.'

See match and match_char

MSA attributes

Methods for setting and reading the MSA attributes.

Note that the methods defining character semantics depend on the user to set them sensibly. They are needed only by certain input/output methods. Unset them by setting to an empty string ('').

id

 Title     : id
 Usage     : $myalign->id("Ig")
 Function  : Gets/sets the id field of the alignment
 Returns   : An id string
 Argument  : An id string (optional)

accession

 Title     : accession
 Usage     : $myalign->accession("PF00244")
 Function  : Gets/sets the accession field of the alignment
 Returns   : An acc string
 Argument  : An acc string (optional)

description

 Title     : description
 Usage     : $myalign->description("14-3-3 proteins")
 Function  : Gets/sets the description field of the alignment
 Returns   : An description string
 Argument  : An description string (optional)

missing_char

 Title     : missing_char
 Usage     : $myalign->missing_char("?")
 Function  : Gets/sets the missing_char attribute of the alignment
             It is generally recommended to set it to 'n' or 'N'
             for nucleotides and to 'X' for protein.
 Returns   : An missing_char string,
 Argument  : An missing_char string (optional)

match_char

 Title     : match_char
 Usage     : $myalign->match_char('.')
 Function  : Gets/sets the match_char attribute of the alignment
 Returns   : An match_char string,
 Argument  : An match_char string (optional)

gap_char

 Title     : gap_char
 Usage     : $myalign->gap_char('-')
 Function  : Gets/sets the gap_char attribute of the alignment
 Returns   : An gap_char string, defaults to '-'
 Argument  : An gap_char string (optional)

symbol_chars

 Title   : symbol_chars
 Usage   : my @symbolchars = $aln->symbol_chars;
 Function: Returns all the seen symbols (other than gaps)
 Returns : array of characters that are the seen symbols
 Args    : boolean to include the gap/missing/match characters

Alignment descriptors

These read only methods describe the MSA in various ways.

score

 Title     : score
 Usage     : $str = $ali->score()
 Function  : get/set a score of the alignment
 Returns   : a score for the alignment
 Argument  : an optional score to set

consensus_string

 Title     : consensus_string
 Usage     : $str = $ali->consensus_string($threshold_percent)
 Function  : Makes a strict consensus
 Returns   : Consensus string
 Argument  : Optional treshold ranging from 0 to 100.
             The consensus residue has to appear at least threshold %
             of the sequences at a given location, otherwise a '?'
             character will be placed at that location.
             (Default value = 0%)

consensus_iupac

 Title     : consensus_iupac
 Usage     : $str = $ali->consensus_iupac()
 Function  : Makes a consensus using IUPAC ambiguity codes from DNA
             and RNA. The output is in upper case except when gaps in
             a column force output to be in lower case.

             Note that if your alignment sequences contain a lot of
             IUPAC ambiquity codes you often have to manually set
             alphabet.  Bio::PrimarySeq::_guess_type thinks they
             indicate a protein sequence.
 Returns   : consensus string
 Argument  : none
 Throws    : on protein sequences

consensus_meta

 Title     : consensus_meta
 Usage     : $seqmeta = $ali->consensus_meta()
 Function  : Returns a Bio::Seq::Meta object containing the consensus
             strings derived from meta data analysis.
 Returns   : Bio::Seq::Meta 
 Argument  : Bio::Seq::Meta 
 Throws    : non-MetaI object

is_flush

 Title     : is_flush
 Usage     : if ( $ali->is_flush() )
 Function  : Tells you whether the alignment
           : is flush, i.e. all of the same length
 Returns   : 1 or 0
 Argument  :

length

 Title     : length()
 Usage     : $len = $ali->length()
 Function  : Returns the maximum length of the alignment.
             To be sure the alignment is a block, use is_flush
 Returns   : Integer
 Argument  :

maxdisplayname_length

 Title     : maxdisplayname_length
 Usage     : $ali->maxdisplayname_length()
 Function  : Gets the maximum length of the displayname in the
             alignment. Used in writing out various MSA formats.
 Returns   : integer
 Argument  :

max_metaname_length

 Title     : max_metaname_length
 Usage     : $ali->max_metaname_length()
 Function  : Gets the maximum length of the meta name tags in the
             alignment for the sequences and for the alignment.
             Used in writing out various MSA formats.
 Returns   : integer
 Argument  : None

no_residues

 Title     : no_residues
 Usage     : $no = $ali->no_residues
 Function  : number of residues in total in the alignment
 Returns   : integer
 Argument  :

no_sequences

 Title     : no_sequences
 Usage     : $depth = $ali->no_sequences
 Function  : number of sequence in the sequence alignment
 Returns   : integer
 Argument  :

average_percentage_identity

 Title   : average_percentage_identity
 Usage   : $id = $align->average_percentage_identity
 Function: The function uses a fast method to calculate the average
           percentage identity of the alignment
 Returns : The average percentage identity of the alignment
 Args    : None
 Notes   : This method implemented by Kevin Howe calculates a figure that is
           designed to be similar to the average pairwise identity of the
           alignment (identical in the absence of gaps), without having to
           explicitly calculate pairwise identities proposed by Richard Durbin.
           Validated by Ewan Birney ad Alex Bateman.

percentage_identity

 Title   : percentage_identity
 Usage   : $id = $align->percentage_identity
 Function: The function calculates the average percentage identity
           (aliased to average_percentage_identity)
 Returns : The average percentage identity
 Args    : None

overall_percentage_identity

 Title   : overall_percentage_identity
 Usage   : $id = $align->overall_percentage_identity
           $id = $align->overall_percentage_identity('short')
 Function: The function calculates the percentage identity of
           the conserved columns
 Returns : The percentage identity of the conserved columns
 Args    : length value to use, optional defaults to alignment length
                 possible values: 'align', 'short', 'long'

The argument values 'short' and 'long' refer to shortest and longest sequence in the alignment. Method modification code by Hongyu Zhang.

Alignment positions

Methods to map a sequence position into an alignment column and back. column_from_residue_number() does the former. The latter is really a property of the sequence object and can done using Bio::LocatableSeq::location_from_column:

    # select somehow a sequence from the alignment, e.g.
    my $seq = $aln->get_seq_by_pos(1);
    #$loc is undef or Bio::LocationI object
    my $loc = $seq->location_from_column(5);

column_from_residue_number

 Title   : column_from_residue_number
 Usage   : $col = $ali->column_from_residue_number( $seqname, $resnumber)
 Function: This function gives the position in the alignment
           (i.e. column number) of the given residue number in the
           sequence with the given name. For example, for the
           alignment

             Seq1/91-97 AC..DEF.GH.
             Seq2/24-30 ACGG.RTY...
                Seq3/43-51 AC.DDEF.GHI

           column_from_residue_number( "Seq1", 94 ) returns 6.
           column_from_residue_number( "Seq2", 25 ) returns 2.
           column_from_residue_number( "Seq3", 50 ) returns 10.

           An exception is thrown if the residue number would lie
           outside the length of the aligment
           (e.g. column_from_residue_number( "Seq2", 22 )

          Note: If the the parent sequence is represented by more than
                one alignment sequence and the residue number is present in
                them, this method finds only the first one.

 Returns : A column number for the position in the alignment of the
           given residue in the given sequence (1 = first column)
 Args    : A sequence id/name (not a name/start-end)
           A residue number in the whole sequence (not just that
           segment of it in the alignment)

Sequence names

Methods to manipulate the display name. The default name based on the sequence id and subsequence positions can be overridden in various ways.

displayname

 Title     : displayname
 Usage     : $myalign->displayname("Ig", "IgA")
 Function  : Gets/sets the display name of a sequence in the alignment
 Returns   : A display name string
 Argument  : name of the sequence
             displayname of the sequence (optional)

set_displayname_count

 Title     : set_displayname_count
 Usage     : $ali->set_displayname_count
 Function  : Sets the names to be name_# where # is the number of
             times this name has been used.
 Returns   : 1, on success
 Argument  :

set_displayname_flat

 Title     : set_displayname_flat
 Usage     : $ali->set_displayname_flat()
 Function  : Makes all the sequences be displayed as just their name,
             not name/start-end
 Returns   : 1
 Argument  :

set_displayname_normal

 Title     : set_displayname_normal
 Usage     : $ali->set_displayname_normal()
 Function  : Makes all the sequences be displayed as name/start-end
 Returns   : 1, on success
 Argument  :

source

 Title   : source
 Usage   : $obj->source($newval)
 Function: sets the Alignment source program
 Example :
 Returns : value of source
 Args    : newvalue (optional)

set_displayname_safe

 Title     : set_displayname_safe
 Usage     : ($new_aln, $ref_name)=$ali->set_displayname_safe(4)
 Function  : Assign machine-generated serial names to sequences in input order.
             Designed to protect names during PHYLIP runs. Assign 10-char string
             in the form of "S000000001" to "S999999999". Restore the original
             names using "restore_displayname".
 Returns   : 1. a new $aln with system names;
             2. a hash ref for restoring names
 Argument  : Number for id length (default 10)

restore_displayname

 Title     : restore_displayname
 Usage     : $aln_name_restored=$ali->restore_displayname($hash_ref)
 Function  : Restore original sequence names (after running
             $ali->set_displayname_safe)
 Returns   : a new $aln with names restored.
 Argument  : a hash reference of names from "set_displayname_safe".

sort_by_start

 Title     : sort_by_start
 Usage     : $ali->sort_by_start
 Function  : Changes the order of the alignment to the start position of each
             subalignment    
 Returns   :
 Argument  :

bracket_string

 Title     : bracket_string
 Usage     : my @params = (-refseq     => 'testseq',
                           -allele1    => 'allele1',
                           -allele2    => 'allele2',
                           -delimiters => '{}',
                           -separator  => '/');
             $str = $aln->bracket_string(@params)

 Function :  When supplied with a list of parameters (see below), returns a
             string in BIC format. This is used for allelic comparisons.
             Briefly, if either allele contains a base change when compared to
             the refseq, the base or gap for each allele is represented in
             brackets in the order present in the 'alleles' parameter.

             For the following data:

             >testseq
             GGATCCATTGCTACT
             >allele1
             GGATCCATTCCTACT
             >allele2
             GGAT--ATTCCTCCT

             the returned string with parameters 'refseq => testseq' and
             'alleles => [qw(allele1 allele2)]' would be:

             GGAT[C/-][C/-]ATT[C/C]CT[A/C]CT
 Returns   : BIC-formatted string
 Argument  : Required args
                refseq    : string (ID) of the reference sequence used
                            as basis for comparison
                allele1   : string (ID) of the first allele
                allele2   : string (ID) of the second allele
             Optional args
                delimiters: two symbol string of left and right delimiters.
                            Only the first two symbols are used
                            default = '[]'
                separator : string used as a separator.  Only the first
                            symbol is used
                            default = '/'
 Throws    : On no refseq/alleles, or invalid refseq/alleles.

methods for Bio::FeatureHolder

FeatureHolder implementation to support labeled character sets like one would get from NEXUS represented data.

get_SeqFeatures

 Usage   :
 Function: Get the feature objects held by this feature holder.
 Example :
 Returns : an array of Bio::SeqFeatureI implementing objects
 Args    : none

At some day we may want to expand this method to allow for a feature filter to be passed in.

add_SeqFeature

 Usage   : $feat->add_SeqFeature($subfeat);
           $feat->add_SeqFeature($subfeat,'EXPAND')
 Function: adds a SeqFeature into the subSeqFeature array.
           with no 'EXPAND' qualifer, subfeat will be tested
           as to whether it lies inside the parent, and throw
           an exception if not.

           If EXPAND is used, the parent''s start/end/strand will
           be adjusted so that it grows to accommodate the new
           subFeature
 Example :
 Returns : nothing
 Args    : a Bio::SeqFeatureI object

remove_SeqFeatures

 Usage   : $obj->remove_SeqFeatures
 Function: Removes all sub SeqFeatures.  If you want to remove only a subset,
           remove that subset from the returned array, and add back the rest.
 Returns : The array of Bio::SeqFeatureI implementing sub-features that was
           deleted from this feature.
 Args    : none

feature_count

 Title   : feature_count
 Usage   : $obj->feature_count()
 Function: Return the number of SeqFeatures attached to a feature holder.

           This is before flattening a possible sub-feature tree.

           We provide a default implementation here that just counts
           the number of objects returned by get_SeqFeatures().
           Implementors may want to override this with a more
           efficient implementation.

 Returns : integer representing the number of SeqFeatures
 Args    : None

At some day we may want to expand this method to allow for a feature filter to be passed in.

Our default implementation allows for any number of additional arguments and will pass them on to get_SeqFeatures(). I.e., in order to support filter arguments, just support them in get_SeqFeatures().

get_all_SeqFeatures

 Title   : get_all_SeqFeatures
 Usage   :
 Function: Get the flattened tree of feature objects held by this
           feature holder. The difference to get_SeqFeatures is that
           the entire tree of sub-features will be flattened out.

           We provide a default implementation here, so implementors
           don''t necessarily need to implement this method.

 Example :
 Returns : an array of Bio::SeqFeatureI implementing objects
 Args    : none

At some day we may want to expand this method to allow for a feature filter to be passed in.

Our default implementation allows for any number of additional arguments and will pass them on to any invocation of get_SeqFeatures(), wherever a component of the tree implements FeatureHolderI. I.e., in order to support filter arguments, just support them in get_SeqFeatures().

methods for Bio::AnnotatableI

AnnotatableI implementation to support sequence alignments which contain annotation (NEXUS, Stockholm).

annotation

 Title   : annotation
 Usage   : $ann = $aln->annotation or 
           $aln->annotation($ann)
 Function: Gets or sets the annotation
 Returns : Bio::AnnotationCollectionI object
 Args    : None or Bio::AnnotationCollectionI object

See Bio::AnnotationCollectionI and Bio::Annotation::Collection for more information