Similus is a Ruby library that allows to find similar objects and recommendations using generated activity. Examples of usage:

• Find similar articles based on what other users also viewed.

• Recommend articles to users based on their activity.

Horaci Cuevas <[email protected]>

Robert R. Meyer <[email protected]>

• Setup

• Store activity

• Show similar objects

• Show recommended objects

Before using Similus, you need to setup the redis configuration. In rails this can be done inside a preinitializer in the config/preinitializers folder.

Similus.config do |config|
  config.backend = :redis
  config.redis_host = "localhost"
  config.redis_port = "6379"
  config.redis_username = "myredisuser"
  config.redis_password = "Password"
  config.redis_db = 8
end

Locate where you want to store activity. For example, in Ruby on Rails, inside the show method of the ArticlesController class:

class ArticlesController < ApplicationController
  def show
    @article = Article.find(params[:id])
    Similus.add_activity(current_user, :show, @article)
  end
end

Once there is some activity stored by users, you can query for similar objects:

class ArticlesController < ApplicationController
  def show
    @article = Article.find(params[:id])
    @similar_articles = Similus.similar_to(@article)
  end
end

Even better than just showing similar articles, show recommended articles for the user’s previous activity when there is a logged in user:

class HomeController < ApplicationController
  def index
    @recommended_articles = Similus.recommended_for(current_user)
  end
end

As of current version, Similus only supports redis backend.

Install Redis 2.0 from [code.google.com/p/redis/] and start the server.

Install the Similus gem:

gem install similus

Copyright © 2010 Horaci Cuevas

See LICENSES for details.