# RRF

RRF (Reciprocal Rank Fusion) is a Ruby gem that provides an implementation of the Reciprocal Rank Fusion (RRF) algorithm to merge and rank results from different search engines, specifically supporting ActiveRecord and Searchkick.

## Installation

Add this line to your application's Gemfile:

```ruby
gem 'rrf'
```

And then execute:

```sh
bundle install
```

Or install it yourself as:

```sh
gem install rrf
```

## Usage

To use RRF, include the module in your ActiveRecord model and configure it as needed.

### Example

Let’s assume you have a model named Chunk that uses both ActiveRecord (with pgvector) and Searchkick:

```ruby
class Chunk < ApplicationRecord
  include Searchkick
  include RRF::Model

  # ActiveRecord vector search using pgvector
  # Assuming `embedding768` is a column of type `vector` (pgvector)

  # Define any additional logic or methods as needed
end
```

### Performing Searches and Fusing Results

You can perform searches using ActiveRecord and Searchkick, and then fuse the results using the fuse method:

```ruby
# Configure the constant value if needed
RRF.configure do |config|
  config.rank_bias = 70 # User-defined value
end

# Perform Searchkick search
es_result = Chunk.search("hi", load: false, limit: 50)

# Perform ActiveRecord nearest neighbor search
query_embedding = [0.1, 0.2, 0.3, ...] # Example embedding
ar_result = Chunk.where("body ilike ?", "%hi%").limit(50)

# Fuse the results and limit to 10
result = Chunk.fuse(ar_result, es_result, limit: 10)

# `result` now contains the top 10 fused search results
```

### Configuration

You can configure the rank_bias value used in the RRF algorithm:

```ruby
RRF.configure do |config|
  config.rank_bias = 70 # Default is 60
end
```

## Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

## Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/assaydepot/rrf.

## License

The gem is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).