Bio/RangeI.pm

   1 #
   2 # BioPerl module for Bio::RangeI
   3 #
   4 # Please direct questions and support issues to <bioperl-l@bioperl.org>
   5 #
   6 # Cared for by Lehvaslaiho <heikki-at-bioperl-dot-org>
   7 #
   8 # Copyright Matthew Pocock
   9 #
  10 # You may distribute this module under the same terms as perl itself
  11 #
  12 # POD documentation - main docs before the code
  13
  14 =head1 NAME
  15
  16 Bio::RangeI - Range interface
  17
  18 =head1 SYNOPSIS
  19
  20   #Do not run this module directly
  21
  22 =head1 DESCRIPTION
  23
  24 This provides a standard BioPerl range interface that should be
  25 implemented by any object that wants to be treated as a range. This
  26 serves purely as an abstract base class for implementers and can not
  27 be instantiated.
  28
  29 Ranges are modeled as having (start, end, length, strand). They use
  30 Bio-coordinates - all points E<gt>= start and E<lt>= end are within the
  31 range. End is always greater-than or equal-to start, and length is
  32 greater than or equal to 1. The behaviour of a range is undefined if
  33 ranges with negative numbers or zero are used.
  34
  35 So, in summary:
  36
  37   length = end - start + 1
  38   end >= start
  39   strand = (-1 | 0 | +1)
  40
  41 =head1 FEEDBACK
  42
  43 =head2 Mailing Lists
  44
  45 User feedback is an integral part of the evolution of this and other
  46 Bioperl modules. Send your comments and suggestions preferably to one
  47 of the Bioperl mailing lists.  Your participation is much appreciated.
  48
  49   bioperl-l@bioperl.org                  - General discussion
  50   http://bioperl.org/wiki/Mailing_lists  - About the mailing lists
  51
  52 =head2 Support
  53
  54 Please direct usage questions or support issues to the mailing list:
  55
  56 I<bioperl-l@bioperl.org>
  57
  58 rather than to the module maintainer directly. Many experienced and
  59 reponsive experts will be able look at the problem and quickly
  60 address it. Please include a thorough description of the problem
  61 with code and data examples if at all possible.
  62
  63 =head2 Reporting Bugs
  64
  65 Report bugs to the Bioperl bug tracking system to help us keep track
  66 the bugs and their resolution.  Bug reports can be submitted via the
  67 web:
  68
  69   https://github.com/bioperl/bioperl-live/issues
  70
  71 =head1 AUTHOR - Heikki Lehvaslaiho
  72
  73 Email:  heikki-at-bioperl-dot-org
  74
  75 =head1 CONTRIBUTORS
  76
  77 Juha Muilu (muilu@ebi.ac.uk)
  78 Sendu Bala (bix@sendu.me.uk)
  79 Malcolm Cook (mec@stowers-institute.org)
  80 Stephen Montgomery (sm8 at sanger.ac.uk)
  81
  82 =head1 APPENDIX
  83
  84 The rest of the documentation details each of the object
  85 methods. Internal methods are usually preceded with a _
  86
  87 =cut
  88
  89 package Bio::RangeI;
  90
  91 use strict;
  92 use Carp;
  93 use integer;
  94 use vars qw(%STRAND_OPTIONS);
  95
  96 use base qw(Bio::Root::RootI);
  97
  98 BEGIN {
  99 # STRAND_OPTIONS contains the legal values for the strand-testing options
 100     %STRAND_OPTIONS = map { $_, '_' . $_ }
 101     (
 102      'strong', # ranges must have the same strand
 103      'weak',   # ranges must have the same strand or no strand
 104      'ignore', # ignore strand information
 105      );
 106 }
 107
 108 # utility methods
 109 #
 110
 111 # returns true if strands are equal and non-zero
 112 sub _strong {
 113     my ($r1, $r2) = @_;
 114     my ($s1, $s2) = ($r1->strand(), $r2->strand());
 115
 116     return 1 if $s1 != 0 && $s1 == $s2;
 117 }
 118
 119 # returns true if strands are equal or either is zero
 120 sub _weak {
 121     my ($r1, $r2) = @_;
 122     my ($s1, $s2) = ($r1->strand(), $r2->strand());
 123     return 1 if $s1 == 0 || $s2 == 0 || $s1 == $s2;
 124 }
 125
 126 # returns true for any strandedness
 127 sub _ignore {
 128     return 1;
 129 }
 130
 131 # works out what test to use for the strictness and returns true/false
 132 # e.g. $r1->_testStrand($r2, 'strong')
 133 sub _testStrand() {
 134     my ($r1, $r2, $comp) = @_;
 135     return 1 unless $comp;
 136     my $func = $STRAND_OPTIONS{$comp};
 137     return $r1->$func($r2);
 138 }
 139
 140 =head1 Abstract methods
 141
 142 These methods must be implemented in all subclasses.
 143
 144 =head2 start
 145
 146   Title   : start
 147   Usage   : $start = $range->start();
 148   Function: get/set the start of this range
 149   Returns : the start of this range
 150   Args    : optionally allows the start to be set
 151             using $range->start($start)
 152
 153 =cut
 154
 155 sub start {
 156     shift->throw_not_implemented();
 157 }
 158
 159 =head2 end
 160
 161   Title   : end
 162   Usage   : $end = $range->end();
 163   Function: get/set the end of this range
 164   Returns : the end of this range
 165   Args    : optionally allows the end to be set
 166             using $range->end($end)
 167
 168 =cut
 169
 170 sub end {
 171     shift->throw_not_implemented();
 172 }
 173
 174 =head2 length
 175
 176   Title   : length
 177   Usage   : $length = $range->length();
 178   Function: get/set the length of this range
 179   Returns : the length of this range
 180   Args    : optionally allows the length to be set
 181              using $range->length($length)
 182
 183 =cut
 184
 185 sub length {
 186     shift->throw_not_implemented();
 187 }
 188
 189 =head2 strand
 190
 191   Title   : strand
 192   Usage   : $strand = $range->strand();
 193   Function: get/set the strand of this range
 194   Returns : the strandedness (-1, 0, +1)
 195   Args    : optionally allows the strand to be set
 196             using $range->strand($strand)
 197
 198 =cut
 199
 200 sub strand {
 201     shift->throw_not_implemented();
 202 }
 203
 204 =head1 Boolean Methods
 205
 206 These methods return true or false. They throw an error if start and
 207 end are not defined.
 208
 209   $range->overlaps($otherRange) && print "Ranges overlap\n";
 210
 211 =head2 overlaps
 212
 213   Title   : overlaps
 214   Usage   : if($r1->overlaps($r2)) { do stuff }
 215   Function: tests if $r2 overlaps $r1
 216   Args    : arg #1 = a range to compare this one to (mandatory)
 217             arg #2 = optional strand-testing arg ('strong', 'weak', 'ignore')
 218   Returns : true if the ranges overlap, false otherwise
 219
 220 =cut
 221
 222 sub overlaps {
 223         my ($self, $other, $so) = @_;
 224
 225         $self->throw("start is undefined") unless defined $self->start;
 226         $self->throw("end is undefined") unless defined $self->end;
 227         $self->throw("not a Bio::RangeI object") unless defined $other &&
 228           $other->isa('Bio::RangeI');
 229         $other->throw("start is undefined") unless defined $other->start;
 230         $other->throw("end is undefined") unless defined $other->end;
 231
 232         return
 233           ($self->_testStrand($other, $so)
 234                 and not (
 235                                         ($self->start() > $other->end() or
 236                                          $self->end() < $other->start()   )
 237                                   ));
 238 }
 239
 240 =head2 contains
 241
 242   Title   : contains
 243   Usage   : if($r1->contains($r2) { do stuff }
 244   Function: tests whether $r1 totally contains $r2
 245   Args    : arg #1 = a range to compare this one to (mandatory)
 246                      alternatively, integer scalar to test
 247             arg #2 = optional strand-testing arg ('strong', 'weak', 'ignore')
 248   Returns : true if the argument is totally contained within this range
 249
 250 =cut
 251
 252 sub contains {
 253         my ($self, $other, $so) = @_;
 254         $self->throw("start is undefined") unless defined $self->start;
 255         $self->throw("end is undefined") unless defined $self->end;
 256
 257         if(defined $other && ref $other) { # a range object?
 258       $other->throw("Not a Bio::RangeI object: $other") unless  $other->isa('Bio::RangeI');
 259       $other->throw("start is undefined") unless defined $other->start;
 260       $other->throw("end is undefined") unless defined $other->end;
 261
 262       return ($self->_testStrand($other, $so)      and
 263                                   $other->start() >= $self->start() and
 264                                   $other->end() <= $self->end());
 265   } else { # a scalar?
 266           $self->throw("'$other' is not an integer.\n") unless $other =~ /^[-+]?\d+$/;
 267           return ($other >= $self->start() and $other <= $self->end());
 268   }
 269 }
 270
 271 =head2 equals
 272
 273   Title   : equals
 274   Usage   : if($r1->equals($r2))
 275   Function: test whether $r1 has the same start, end, length as $r2
 276   Args    : arg #1 = a range to compare this one to (mandatory)
 277             arg #2 = optional strand-testing arg ('strong', 'weak', 'ignore')
 278   Returns : true if they are describing the same range
 279
 280 =cut
 281
 282 sub equals {
 283     my ($self, $other, $so) = @_;
 284
 285     $self->throw("start is undefined") unless defined $self->start;
 286     $self->throw("end is undefined") unless defined $self->end;
 287     $other->throw("Not a Bio::RangeI object") unless  $other->isa('Bio::RangeI');
 288     $other->throw("start is undefined") unless defined $other->start;
 289     $other->throw("end is undefined") unless defined $other->end;
 290
 291     return ($self->_testStrand($other, $so)   and
 292             $self->start() == $other->start() and
 293             $self->end()   == $other->end()       );
 294 }
 295
 296 =head1 Geometrical methods
 297
 298 These methods do things to the geometry of ranges, and return
 299 Bio::RangeI compliant objects or triplets (start, stop, strand) from
 300 which new ranges could be built.
 301
 302 =head2 intersection
 303
 304  Title   : intersection
 305  Usage   : ($start, $end, $strand) = $r1->intersection($r2); OR
 306            ($start, $end, $strand) = Bio::Range->intersection(\@ranges); OR
 307            my $containing_range = $r1->intersection($r2); OR
 308            my $containing_range = Bio::Range->intersection(\@ranges);
 309  Function: gives the range that is contained by all ranges
 310  Returns : undef if they do not overlap or if @ranges has only a
 311            single range, else returns the range that they do
 312            overlap. In scalar contex, the return value is an object of
 313            the same class as the calling one. In array context the
 314            return value is a three element array.
 315  Args    : arg #1 = [REQUIRED] a Bio::RangeI to compare this one to,
 316                     or an array ref of ranges
 317            arg #2 = optional strand-testing arg ('strong', 'weak', 'ignore')
 318
 319 =cut
 320
 321 sub intersection {
 322         my ($self, $given, $so) = @_;
 323         $self->throw("missing arg: you need to pass in another feature") unless $given;
 324
 325     my @ranges;
 326     if ($self eq "Bio::RangeI") {
 327                 $self = "Bio::Range";
 328                 $self->warn("calling static methods of an interface is deprecated; use $self instead");
 329         }
 330         if (ref $self) {
 331                 push(@ranges, $self);
 332         }
 333     ref($given) eq 'ARRAY' ? push(@ranges, @{$given}) : push(@ranges, $given);
 334     #$self->throw("Need at least 2 ranges") unless @ranges >= 2;
 335     # Rather than the above, I think the following is more consistent
 336     return undef unless @ranges >= 2;
 337
 338     my $intersect;
 339     while (@ranges > 0) {
 340         unless ($intersect) {
 341             $intersect = shift(@ranges);
 342             $self->throw("Not an object: $intersect") unless ref($intersect);
 343             $self->throw("Not a Bio::RangeI object: $intersect") unless $intersect->isa('Bio::RangeI');
 344             $self->throw("start is undefined") unless defined $intersect->start;
 345             $self->throw("end is undefined") unless defined $intersect->end;
 346         }
 347
 348         my $compare = shift(@ranges);
 349         $self->throw("Not an object: $compare") unless ref($compare);
 350         $self->throw("Not a Bio::RangeI object: $compare") unless $compare->isa('Bio::RangeI');
 351         $self->throw("start is undefined") unless defined $compare->start;
 352         $self->throw("end is undefined") unless defined $compare->end;
 353         return unless $compare->_testStrand($intersect, $so);
 354
 355         my @starts = sort {$a <=> $b} ($intersect->start(), $compare->start());
 356         my @ends   = sort {$a <=> $b} ($intersect->end(), $compare->end());
 357
 358         my $start = pop @starts; # larger of the 2 starts
 359         my $end = shift @ends;   # smaller of the 2 ends
 360
 361         my $intersect_strand;    # strand for the intersection
 362         if (defined($intersect->strand) && defined($compare->strand) && $intersect->strand == $compare->strand) {
 363             $intersect_strand = $compare->strand;
 364         }
 365         else {
 366             $intersect_strand = 0;
 367         }
 368
 369         if ($start > $end) {
 370             return;
 371         }
 372         else {
 373             $intersect = $self->new(-start  => $start,
 374                                     -end    => $end,
 375                                     -strand => $intersect_strand);
 376         }
 377     }
 378
 379     if (wantarray()) {
 380         return ($intersect->start, $intersect->end, $intersect->strand);
 381     }
 382     else {
 383         return $intersect;
 384     }
 385 }
 386
 387 =head2 union
 388
 389    Title   : union
 390     Usage   : ($start, $end, $strand) = $r1->union($r2);
 391             : ($start, $end, $strand) = Bio::Range->union(@ranges);
 392               my $newrange = Bio::Range->union(@ranges);
 393     Function: finds the minimal Range that contains all of the Ranges
 394     Args    : a Range or list of Range objects
 395
 396     Returns : the range containing all of the range. In scalar contex,
 397               the return value is an object of the same class as the
 398               calling one. In array context the return value is a
 399               three element array.
 400
 401 =cut
 402
 403 sub union {
 404         my $self = shift;
 405         my @ranges = @_;
 406         if ($self eq "Bio::RangeI") {
 407                 $self = "Bio::Range";
 408                 $self->warn("calling static methods of an interface is deprecated; use $self instead");
 409         }
 410         if(ref $self) {
 411                 unshift @ranges, $self;
 412         }
 413
 414         my @start = sort {$a<=>$b}
 415           map( { $_->start() } @ranges);
 416         my @end   = sort {$a<=>$b}
 417           map( { $_->end()   } @ranges);
 418
 419         my $start = shift @start;
 420         while( !defined $start ) {
 421                 $start = shift @start;
 422         }
 423
 424         my $end = pop @end;
 425
 426         my $union_strand;  # Strand for the union range object.
 427
 428         foreach(@ranges) {
 429                 if(! defined $union_strand) {
 430                         $union_strand = $_->strand;
 431                         next;
 432                 } else {
 433                         if(not defined $_->strand or $union_strand ne $_->strand) {
 434                                 $union_strand = 0;
 435                                 last;
 436                         }
 437                 }
 438         }
 439         return unless $start or $end;
 440         if( wantarray() ) {
 441                 return ( $start,$end,$union_strand);
 442         } else {
 443                 return $self->new('-start' => $start,
 444                                                                 '-end' => $end,
 445                                                                 '-strand' => $union_strand
 446                                                           );
 447         }
 448 }
 449
 450 =head2 overlap_extent
 451
 452  Title   : overlap_extent
 453  Usage   : ($a_unique,$common,$b_unique) = $a->overlap_extent($b)
 454  Function: Provides actual amount of overlap between two different
 455            ranges
 456  Example :
 457  Returns : array of values containing the length unique to the calling
 458            range, the length common to both, and the length unique to
 459            the argument range
 460  Args    : a range
 461
 462 =cut
 463
 464 sub overlap_extent{
 465         my ($a,$b) = @_;
 466
 467         $a->throw("start is undefined") unless defined $a->start;
 468         $a->throw("end is undefined") unless defined $a->end;
 469         $b->throw("Not a Bio::RangeI object") unless  $b->isa('Bio::RangeI');
 470         $b->throw("start is undefined") unless defined $b->start;
 471         $b->throw("end is undefined") unless defined $b->end;
 472
 473         if( ! $a->overlaps($b) ) {
 474             return ($a->length,0,$b->length);
 475         }
 476
 477         my ($au,$bu) = (0, 0);
 478         if( $a->start < $b->start ) {
 479                 $au = $b->start - $a->start;
 480         } else {
 481                 $bu = $a->start - $b->start;
 482         }
 483
 484         if( $a->end > $b->end ) {
 485                 $au += $a->end - $b->end;
 486         } else {
 487                 $bu += $b->end - $a->end;
 488         }
 489
 490         my $intersect = $a->intersection($b);
 491         if( ! $intersect ) {
 492             warn("no intersection\n");
 493             return ($au, 0, $bu);
 494         } else {
 495             my $ie = $intersect->end;
 496             my $is = $intersect->start;
 497             return ($au,$ie-$is+1,$bu);
 498         }
 499 }
 500
 501 =head2 disconnected_ranges
 502
 503     Title   : disconnected_ranges
 504     Usage   : my @disc_ranges = Bio::Range->disconnected_ranges(@ranges);
 505     Function: finds the minimal set of ranges such that each input range
 506               is fully contained by at least one output range, and none of
 507               the output ranges overlap
 508     Args    : a list of ranges
 509     Returns : a list of objects of the same type as the input
 510               (conforms to RangeI)
 511
 512 =cut
 513
 514 sub disconnected_ranges {
 515     my $self = shift;
 516     if ($self eq "Bio::RangeI") {
 517         $self = "Bio::Range";
 518         $self->warn("calling static methods of an interface is deprecated; use $self instead");
 519     }
 520     my @inranges = @_;
 521     if(ref $self) {
 522         unshift @inranges, $self;
 523     }
 524
 525     my @outranges = (); # disconnected ranges
 526
 527     # iterate through all input ranges $inrange,
 528     # adding each input range to the set of output ranges @outranges,
 529     # provided $inrange does not overlap ANY range in @outranges
 530     # - if it does overlap an outrange, then merge it
 531     foreach my $inrange (@inranges) {
 532         my $intersects = 0;
 533         my @outranges_new = ();
 534         my @intersecting_ranges = ();
 535
 536         # iterate through all @outranges, testing if it intersects
 537         # current $inrange; if it does, merge and add to list
 538         # of @intersecting_ranges, otherwise add $outrange to
 539         # the new list of outranges that do NOT intersect
 540         for (my $i=0; $i<@outranges; $i++) {
 541             my $outrange = $outranges[$i];
 542             my $intersection = $inrange->intersection($outrange);
 543             if ($intersection) {
 544                 $intersects = 1;
 545                 my $union = $inrange->union($outrange);
 546                 push(@intersecting_ranges, $union);
 547             }
 548             else {
 549                 push(@outranges_new, $outrange);
 550             }
 551         }
 552         @outranges = @outranges_new;
 553         # @outranges now contains a list of non-overlapping ranges
 554         # that do not intersect the current $inrange
 555
 556         if (@intersecting_ranges) {
 557             if (@intersecting_ranges > 1) {
 558                 # this sf intersected > 1 range, which means that
 559                 # all the ranges it intersects should be joined
 560                 # together in a new range
 561                 my $merged_range =
 562                   $self->union(@intersecting_ranges);
 563                 push(@outranges, $merged_range);
 564
 565             }
 566             else {
 567                 # exactly 1 intersecting range
 568                 push(@outranges, @intersecting_ranges);
 569             }
 570         }
 571         else {
 572             # no intersections found - new range
 573             push(@outranges,
 574                  $self->new('-start'=>$inrange->start,
 575                             '-end'=>$inrange->end,
 576                             '-strand'=>$inrange->strand,
 577                            ));
 578         }
 579     }
 580     return @outranges;
 581 }
 582
 583 =head2 offsetStranded
 584
 585     Title    : offsetStranded
 586     Usage    : $rnge->ofsetStranded($fiveprime_offset, $threeprime_offset)
 587     Function : destructively modifies RangeI implementing object to
 588                offset its start and stop coordinates by values $fiveprime_offset and
 589                $threeprime_offset (positive values being in the strand direction).
 590     Args     : two integer offsets: $fiveprime_offset and $threeprime_offset
 591     Returns  : $self, offset accordingly.
 592
 593 =cut
 594
 595 sub offsetStranded {
 596   my ($self, $offset_fiveprime, $offset_threeprime) = @_;
 597   my ($offset_start, $offset_end) = $self->strand() eq -1 ? (- $offset_threeprime, - $offset_fiveprime) : ($offset_fiveprime, $offset_threeprime);
 598   $self->start($self->start + $offset_start);
 599   $self->end($self->end + $offset_end);
 600   return $self;
 601 };
 602
 603 =head2 subtract
 604
 605   Title   : subtract
 606   Usage   : my @subtracted = $r1->subtract($r2)
 607   Function: Subtract range r2 from range r1
 608   Args    : arg #1 = a range to subtract from this one (mandatory)
 609             arg #2 = strand option ('strong', 'weak', 'ignore') (optional)
 610   Returns : undef if they do not overlap or r2 contains this RangeI,
 611             or an arrayref of Range objects (this is an array since some
 612             instances where the subtract range is enclosed within this range
 613             will result in the creation of two new disjoint ranges)
 614
 615 =cut
 616
 617 sub subtract() {
 618    my ($self, $range, $so) = @_;
 619     $self->throw("missing arg: you need to pass in another feature")
 620       unless $range;
 621     return unless $self->_testStrand($range, $so);
 622
 623     if ($self eq "Bio::RangeI") {
 624         $self = "Bio::Range";
 625         $self->warn("calling static methods of an interface is
 626 deprecated; use $self instead");
 627     }
 628     $range->throw("Input a Bio::RangeI object") unless
 629 $range->isa('Bio::RangeI');
 630
 631     my @sub_locations;
 632     if ($self->location->isa('Bio::Location::SplitLocationI') ) {
 633        @sub_locations = $self->location->sub_Location;
 634     } else {
 635        @sub_locations = $self;
 636     }
 637
 638     my @outranges;
 639     foreach my $sl (@sub_locations) {
 640        if (!$sl->overlaps($range)) {
 641           push(@outranges,
 642              $self->new('-start' =>$sl->start,
 643                         '-end'   =>$sl->end,
 644                         '-strand'=>$sl->strand,
 645           ));
 646           next;
 647        }
 648
 649        ##Subtracts everything
 650        if ($range->contains($sl)) {
 651           next;
 652        }
 653
 654        my ($start, $end, $strand) = $sl->intersection($range, $so);
 655        ##Subtract intersection from $self range
 656
 657        if ($sl->start < $start) {
 658           push(@outranges,
 659              $self->new('-start' =>$sl->start,
 660                         '-end'   =>$start - 1,
 661                         '-strand'=>$sl->strand,
 662           ));
 663        }
 664        if ($sl->end > $end) {
 665           push(@outranges,
 666              $self->new('-start' =>$end + 1,
 667                         '-end'   =>$sl->end,
 668                         '-strand'=>$sl->strand,
 669           ));
 670        }
 671     }
 672
 673     if (@outranges) {
 674        return \@outranges;
 675     }
 676     return;
 677 }
 678
 679 1;