Bio/Taxonomy.pm

   1 #
   2 # BioPerl module for Bio::Taxonomy
   3 #
   4 # Please direct questions and support issues to <bioperl-l@bioperl.org>
   5 #
   6 # Cared for by Juguang Xiao
   7 #
   8 # You may distribute this module under the same terms as perl itself
   9
  10 # POD documentation - main docs before the code
  11
  12 =head1 NAME
  13
  14 Bio::Taxonomy - representing Taxonomy.
  15
  16 =head1 SYNOPSIS
  17
  18   # NB: This module is deprecated. Use Bio::Taxon in combination with
  19   # Bio::Tree::Tree methods instead.
  20
  21   use Bio::Taxonomy;
  22
  23   # CREATION: You can either create an instance by assigning it,
  24   # or fetch it through factory.
  25
  26   # Create the nodes first. See Bio::Taxonomy::Node for details.
  27   my $node_species_sapiens = Bio::Taxonomy::Node->new(
  28       -object_id => 9606, # or -ncbi_taxid. Requird tag
  29       -names => {
  30           'scientific' => ['sapiens'],
  31           'common_name' => ['human']
  32       },
  33       -rank => 'species'  # Required tag
  34   );
  35   my $node_genus_Homo = Bio::Taxonomy::Node->new(
  36       -object_id => 9605,
  37       -names => { 'scientific' => ['Homo'] },
  38       -rank => 'genus'
  39   );
  40   my $node_class_Mammalia = Bio::Taxonomy::Node->new(
  41       -object_id => 40674,
  42       -names => {
  43           'scientific' => ['Mammalia'],
  44           'common' => ['mammals']
  45       },
  46       -rank => 'class'
  47   );
  48   my $taxonomy = Bio::Taxonomy->new;
  49   $taxonomy->add_node($node_class_Mammalia);
  50   $taxonomy->add_node($node_species_sapiens);
  51   $taxonomy->add_node($node_genus_Homo);
  52
  53   # OR you can fetch it through a factory implementing
  54   # Bio::Taxonomy::FactoryI
  55   my $factory;
  56
  57   my $taxonomy = $factory->fetch_by_ncbi_taxid(40674);
  58
  59   # USAGE
  60
  61   # In this case, binomial returns a defined value.
  62   my $binomial = $taxonomy->binomial;
  63
  64   # 'common_names' refers to the lowest-rank node's common names, in
  65   # array.
  66   my @common_names = $taxonomy->common_names;
  67
  68   # 'get_node', will return undef if the rank is no defined in
  69   # taxonomy object.  It will throw error if the rank string is not
  70   # defined, say 'species lah'.
  71   my $node = $taxonomy->get_node('class');
  72   my @nodes = $taxonomy->get_all_nodes;
  73
  74   # Also, you can search for parent and children nodes, if taxonomy
  75   # comes with factory.
  76
  77   my $parent_taxonomy = $taxonomy->get_parent
  78
  79 =head1 DESCRIPTION
  80
  81 Bio::Taxonomy object represents any rank-level in taxonomy system,
  82 rather than Bio::Species which is able to represent only
  83 species-level.
  84
  85 There are two ways to create Taxonomy object, e.g.
  86 1) instantiate an object and assign all nodes on your own code; and
  87 2) fetch an object by factory.
  88
  89 =head2 Creation by instantiation
  90
  91 The abstraction of Taxonomy is actually a hash in data structure
  92 term. The keys of the hash are the rank names, such as 'genus' and
  93 'species', and the values are the instances of Bio::Taxonomy::Node.
  94
  95 =head2 Creation by Factory fetching
  96
  97 NCBI Taxonomy system is well accepted as the standard. The Taxonomy
  98 Factories in bioperl access this system, through HTTP to NCBI Entrez,
  99 dump file, and advanced biosql database.
 100
 101 Bio::Taxonomy::FactoryI defines all methods that all implementations
 102 must obey.
 103
 104 $factory-E<gt>fetch is a general method to fetch Taxonomy by either
 105 NCBI taxid or any types of names.
 106
 107 $factory-E<gt>fetch_parent($taxonomy), returns a Taxonomy that is
 108 one-step higher rank of the taxonomy specified as argument.
 109
 110 $factory-E<gt>fetch_children($taxonomy), reports an array of Taxonomy
 111 those are one-step lower rank of the taxonomy specified as the
 112 argument.
 113
 114 =head2 Usage of Taxonomy object
 115
 116 ##
 117
 118 =head1 FEEDBACK
 119
 120 =head2 Mailing Lists
 121
 122 User feedback is an integral part of the evolution of this and other
 123 Bioperl modules. Send your comments and suggestions preferably to
 124 the Bioperl mailing list.  Your participation is much appreciated.
 125
 126   bioperl-l@bioperl.org                  - General discussion
 127   http://bioperl.org/wiki/Mailing_lists  - About the mailing lists
 128
 129 =head2 Support
 130
 131 Please direct usage questions or support issues to the mailing list:
 132
 133 I<bioperl-l@bioperl.org>
 134
 135 rather than to the module maintainer directly. Many experienced and
 136 reponsive experts will be able look at the problem and quickly
 137 address it. Please include a thorough description of the problem
 138 with code and data examples if at all possible.
 139
 140 =head2 Reporting Bugs
 141
 142 Report bugs to the Bioperl bug tracking system to help us keep track
 143 of the bugs and their resolution. Bug reports can be submitted via the
 144 web:
 145
 146   https://redmine.open-bio.org/projects/bioperl/
 147
 148 =head1 CONTACT
 149
 150 Juguang Xiao, juguang@tll.org.sg
 151
 152 =head1 APPENDIX
 153
 154 The rest of the documentation details each of the object
 155 methods. Internal methods are usually preceded with a _
 156
 157 =cut
 158
 159
 160 # code begins...
 161
 162
 163 package Bio::Taxonomy;
 164 use strict;
 165
 166
 167 use base qw(Bio::Root::Root);
 168
 169
 170 =head2 new
 171
 172  Title   : new
 173  Usage   : my $obj = Bio::Taxonomy->new();
 174  Function: Builds a new Bio::Taxonomy object
 175  Returns : Bio::Taxonomy
 176  Args    : -method  -> method used to decide classification
 177                        (none|trust|lookup)
 178            -ranks   -> what ranks are there
 179
 180 =cut
 181
 182
 183 sub new {
 184    my ($class,@args) = @_;
 185
 186    my $self = $class->SUPER::new(@args);
 187    $self->warn("Bio::Taxonomy is deprecated. Use Bio::Taxon in combination with Bio::Tree::Tree instead.");
 188
 189    $self->{'_method'}='none';
 190    $self->{'_ranks'}=[];
 191    $self->{'_rank_hash'}={};
 192     $self->{_hierarchy} = {}; # used to store the nodes, with ranks as keys.
 193    my ($method,$ranks,$order) = $self->_rearrange([qw(METHOD RANKS ORDER)], @args);
 194
 195    if ($method) {
 196       $self->method($method);
 197    }
 198
 199    if (defined $ranks &&
 200       (ref($ranks) eq "ARRAY") ) {
 201       $self->ranks(@$ranks);
 202    } else {
 203       # default ranks
 204       # I think these are in the right order, but not sure:
 205       # some parvorder|suborder and varietas|subspecies seem
 206       # to be at the same level - any taxonomists?
 207       # I don't expect that these will actually be used except as a way
 208       # to find what ranks there are in taxonomic use
 209       $self->ranks(('root',
 210         'superkingdom', 'kingdom',
 211         'superphylum', 'phylum', 'subphylum',
 212         'superclass', 'class', 'subclass', 'infraclass',
 213         'superorder', 'order', 'suborder', 'parvorder', 'infraorder',
 214         'superfamily', 'family', 'subfamily',
 215         'tribe', 'subtribe',
 216         'genus', 'subgenus',
 217         'species group', 'species subgroup', 'species', 'subspecies',
 218         'varietas', 'forma', 'no rank'));
 219    }
 220
 221    return $self;
 222 }
 223
 224
 225 =head2 method
 226
 227  Title   : method
 228  Usage   : $obj = taxonomy->method($method);
 229  Function: set or return the method used to decide classification
 230  Returns : $obj
 231  Args    : $obj
 232
 233 =cut
 234
 235
 236 sub method {
 237    my ($self,$value) = @_;
 238    if (defined $value && $value=~/none|trust|lookup/) {
 239        $self->{'_method'} = $value;
 240    }
 241    return $self->{'_method'};
 242 }
 243
 244
 245 =head2 classify
 246
 247  Title   : classify
 248  Usage   : @obj[][0-1] = taxonomy->classify($species);
 249  Function: return a ranked classification
 250  Returns : @obj of taxa and ranks as word pairs separated by "@"
 251  Args    : Bio::Species object
 252
 253 =cut
 254
 255
 256 sub classify {
 257    my ($self,$value) = @_;
 258    my @ranks;
 259
 260    if (! $value->isa('Bio::Species') ) {
 261       $self->throw("Trying to classify $value which is not a Bio::Species object");
 262    }
 263
 264    my @classes=reverse($value->classification);
 265
 266    if ($self->method eq 'none') {
 267       for (my $i=0; $i < @classes-2; $i++) {
 268          ($ranks[$i][0],$ranks[$i][1])=($classes[$i],'no rank');
 269       }
 270       push @ranks,[$classes[-2],'genus'];
 271       push @ranks,[$value->binomial,'species'];
 272    } elsif ($self->method eq 'trust') {
 273       if (scalar(@classes)==scalar($self->ranks)) {
 274          for (my $i=0; $i < @classes; $i++) {
 275             if ($self->rank_of_number($i) eq 'species') {
 276                push @ranks,[$value->binomial,$self->rank_of_number($i)];
 277             } else {
 278                push @ranks,[$classes[$i],$self->rank_of_number($i)];
 279             }
 280          }
 281       } else {
 282          $self->throw("Species object and taxonomy object cannot be reconciled");
 283       }
 284    } elsif ($self->method eq 'lookup') {
 285       # this will lookup a DB for the rank of a taxon name
 286       # I imagine that some kind of Bio::DB class will be need to
 287       # be given to the taxonomy object to act as an DB interface
 288       # (I'm not sure how useful this is though - if you have a DB of
 289       # taxonomy - why would you be doing things this way?)
 290       $self->throw_not_implemented();
 291    }
 292
 293    return @ranks;
 294 }
 295
 296
 297 =head2 level_of_rank
 298
 299  Title   : level_of_rank
 300  Usage   : $obj = taxonomy->level_of_rank($obj);
 301  Function: returns the level of a rank name
 302  Returns : $obj
 303  Args    : $obj
 304
 305 =cut
 306
 307
 308 sub level_of {
 309    my ($self,$value) = @_;
 310
 311    return $self->{'_rank_hash'}{$value};
 312 }
 313
 314
 315 =head2 rank_of_number
 316
 317  Title   : rank_of_number
 318  Usage   : $obj = taxonomy->rank_of_number($obj);
 319  Function: returns the rank name of a rank level
 320  Returns : $obj
 321  Args    : $obj
 322
 323 =cut
 324
 325
 326 sub rank_of_number {
 327    my ($self,$value) = @_;
 328
 329    return ${$self->{'_ranks'}}[$value];
 330 }
 331
 332
 333 =head2 ranks
 334
 335  Title   : ranks
 336  Usage   : @obj = taxonomy->ranks(@obj);
 337  Function: set or return all ranks
 338  Returns : @obj
 339  Args    : @obj
 340
 341 =cut
 342
 343
 344 sub ranks {
 345    my ($self,@value) = @_;
 346
 347    # currently this makes no uniqueness sanity check (this should be done)
 348    # I am think that adding a way of converting multiple 'no rank' ranks
 349    # to unique 'no rank #' ranks so that the level of a 'no rank' is
 350    # abstracted way from the user - I'm not sure of the value of this
 351
 352    if (@value) {
 353       $self->{'_ranks'}=\@value;
 354    }
 355
 356    for (my $i=0; $i <= @{$self->{'_ranks'}}-1; $i++) {
 357       $self->{'_rank_hash'}{$self->{'_ranks'}[$i]}=$i unless $self->{'_ranks'}[$i] eq 'no rank';
 358    }
 359
 360    return @{$self->{'_ranks'}};
 361 }
 362
 363 =head2 add_node
 364
 365   Title:    add_node
 366   Usage:    $obj->add_node($node[, $node2, ...]);
 367   Function: add one or more Bio::Taxonomy::Node objects
 368   Returns:  None
 369   Args:     any number of Bio::Taxonomy::Node(s)
 370
 371 =cut
 372
 373 sub add_node {
 374     my ($self, @nodes) = @_;
 375     foreach(@nodes){
 376         $self->throw("A Bio::Taxonomy::Node object needed")
 377             unless($_->isa('Bio::Taxonomy::Node'));
 378         my ($node, $rank) = ($_, $_->rank);
 379         if(exists $self->{_hierarchy}->{$rank}){
 380 #            $self->throw("$rank has been defined");
 381 #            print STDERR "RANK:$rank\n";
 382 #            return;
 383         }
 384         $self->{_hierarchy}->{$rank} = $node;
 385     }
 386 }
 387
 388 =head2 binomial
 389
 390   Title   : binomial
 391   Usage   : my $val = $obj->binomial;
 392   Function: returns the binomial name if this taxonomy reachs species level
 393   Returns : the binomial name
 394             OR undef if taxonmy does not reach species level
 395   Args    : [No arguments]
 396
 397 =cut
 398
 399 sub binomial {
 400     my $self = shift;
 401     return $self->get_node('species')->scientific_name;
 402     my $genus = $self->get_node('genus');
 403     my $species = $self->get_node('species');
 404     return ($species && $genus) ? "$species $genus" : undef;
 405 }
 406
 407 =head2 get_node
 408
 409   Title   : get_node
 410   Usage   : $node = $taxonomy->get_node('species');
 411   Function: get a Bio::Taxonomy::Node object according to rank name
 412   Returns : a Bio::Taxonomy::Node object or undef if null
 413   Args    : a vaild rank name
 414
 415 =cut
 416
 417 sub get_node {
 418     my ($self, $rank) = @_;
 419     unless(grep /$rank/, keys %{$self->{_hierarchy}}){
 420         $self->throw("'$rank' is not in the rank list");
 421     }
 422     return (exists $self->{_hierarchy}->{$rank})?
 423         $self->{_hierarchy}->{$rank} : undef;
 424 }
 425
 426 =head2 classification
 427
 428   Title   : classification
 429   Usage   : @names = $taxonomy->classification;
 430   Function: get the classification names of one taxonomy
 431   Returns : array of names
 432   Args    : [No arguments]
 433
 434 =cut
 435
 436 sub classification {
 437     my $self = shift;
 438     my %rank_hash = %{$self->{_rank_hash}};
 439     my %hierarchy = %{$self->{_hierarchy}};
 440     my @ordered_nodes = sort {
 441         ($rank_hash{$a} <=> $rank_hash{$b})
 442     } keys %hierarchy;
 443     return map {$hierarchy{$_}->scientific_name} @ordered_nodes;
 444 }
 445
 446 1;