# UMLS::Similarity::random.pm
#
# Module which assigns a random number between zero and one as 
# the similarity score
#
# Copyright (c) 2009-2011,
#
# Bridget T McInnes, University of Minnesota, Twin Cities
# bthomson at umn.edu
#
# Siddharth Patwardhan, University of Utah, Salt Lake City
# sidd at cs.utah.edu
#
# Serguei Pakhomov, University of Minnesota, Twin Cities
# pakh002 at umn.edu
#
# Ted Pedersen, University of Minnesota, Duluth
# tpederse at d.umn.edu
#
# Ying Liu, University of Minnesota
# liux0935 at umn.edu
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to 
#
# The Free Software Foundation, Inc., 
# 59 Temple Place - Suite 330, 
# Boston, MA  02111-1307, USA.


package UMLS::Similarity::random;

use strict;
use warnings;
use UMLS::Similarity;
use UMLS::Similarity::ErrorHandler;

use vars qw($VERSION);
$VERSION = '0.05';

my $debug = 0;

sub new
{
    my $className = shift;
    return undef if(ref $className);

    if($debug) { print STDERR "In UMLS::Similarity::random->new()\n"; }

    my $interface = shift;

    my $self = {};
     
    # Bless the object.
    bless($self, $className);
    
    # The backend interface object.
    $self->{'interface'} = $interface;
    
    return $self;
}


sub getRelatedness
{
    my $self = shift;

    return undef if(!defined $self || !ref $self);

    my $concept1 = shift;
    my $concept2 = shift;
    
    #  return a random number between zero and one
    my $score = rand();
    
    return $score
}

1;
__END__

=head1 NAME

UMLS::Similarity::random - Perl module for computing a random baseline 
by assigning a random number between zero and one as the similarity score.

=head1 SYNOPSIS

  use UMLS::Interface;
  use UMLS::Similarity::random;

  my $umls = UMLS::Interface->new(); 
  die "Unable to create UMLS::Interface object.\n" if(!$umls);

  my $random = UMLS::Similarity::random->new($umls);
  die "Unable to create measure object.\n" if(!$random);

  my $cui1 = "C0005767";
  my $cui2 = "C0007634";

  $ts1 = $umls->getTermList($cui1);
  my $term1 = pop @{$ts1};

  $ts2 = $umls->getTermList($cui2);
  my $term2 = pop @{$ts2};

  my $value = $random->getRelatedness($cui1, $cui2);

  print "The similarity between $cui1 ($term1) and $cui2 ($term2) is $value\n";

=head1 DESCRIPTION

This module assigns a random number between zero and one as the 
semantic relatedness of two concepts in the UMLS 

=head1 USAGE

The semantic relatedness modules in this distribution are built as classes
that expose the following methods:
  new()
  getRelatedness()

=head1 TYPICAL USAGE EXAMPLES

To create an object of the random measure, we would have the following
lines of code in the perl program. 

   use UMLS::Similarity::random;
   $measure = UMLS::Similarity::random->new($interface);

The reference of the initialized object is stored in the scalar
variable '$measure'. '$interface' contains an interface object that
should have been created earlier in the program (UMLS-Interface). 

If the 'new' method is unable to create the object, '$measure' would 
be undefined. 

To find the semantic relatedness of the concept 'blood' (C0005767) and
the concept 'cell' (C0007634) using the measure, we would write
the following piece of code:

   $relatedness = $measure->getRelatedness('C0005767', 'C0007634');

=head1 SEE ALSO

perl(1), UMLS::Interface

perl(1), UMLS::Similarity(3)

=head1 AUTHORS

  Bridget T McInnes <bthomson at cs.umn.edu>
  Siddharth Patwardhan <sidd at cs.utah.edu>
  Serguei Pakhomov <pakh0002 at umn.edu>
  Ted Pedersen <tpederse at d.umn.edu>

=head1 COPYRIGHT AND LICENSE

Copyright 2004-2011 by Bridget T McInnes, Siddharth Patwardhan, 
Serguei Pakhomov, Ying Liu and Ted Pedersen

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself. 

=cut