ActsAsSimilar
=============

I had a need to find items that were similar to an item. I looked at acts_as_recommendable, and while this was very
nice plugin, it was too slow when working with large data sets. I also decided that the results I needed didn't need
to be scientifically accurate, just a rough match. So I created this plugin to allow for a very elementary way to find 
items
that are similar to the object you are working with. This works best when used with a has_many :through relationship.

Basically all it is doing is looking for other objects of the same class, that have some related value.

Example 1
=========
Look for similar playlists, using the videos as what defines similarity.
This will look for all playlists that have a similar video as the playlist you are looking against.

class Playlist
  has_many :playlists_videos
  has_many :videos, :through => :playlists_videos

  acts_as_similar :videos
end


Example 2
=========
Look for similar playlists, using the title of the playlist as the similarity item.
This will look for all playlists that have a similar title as the playlist you are looking against.

class Playlist
  has_many :playlists_videos
  has_many :videos, :through => :playlists_videos

  acts_as_similar :field => :title
end


Example 3
=========
Look for similar playlists, using the video_id of the playlists_videos as the similarity item.
This will look for all playlists that have a similar video_id as the playlist you are looking against.

class Playlist
  has_many :playlists_videos
  has_many :videos, :through => :playlists_videos

  acts_as_similar :playlists_videos, :field => :video_id
end


Execute
=========
@playlist = Playlist.first
@playlist.similar


Notes
=========
This is a work in progress and is intended to provide very basic functionality.

Copyright (c) 2009 [Randy Girard (randy_at_freezzo_dot_com, http://www.freezzo.com], released under the MIT license