Vicinity is a light-weight, low-dependency vector store. It provides a simple and intuitive interface for nearest neighbor search, with support for different backends and evaluation.

There are many nearest neighbors packages and methods out there. However, we found it difficult to compare them. Every package has its own interface, quirks, and limitations, and learning a new package can be time-consuming. In addition to that, how do you effectively evaluate different packages? How do you know which one is the best for your use case?

This is where Vicinity comes in. Instead of learning a new interface for each new package or backend, Vicinity provides a unified interface for all backends. This allows you to easily experiment with different indexing methods and distance metrics and choose the best one for your use case. Vicinity also provides a simple way to evaluate the performance of different backends, allowing you to measure the queries per second and recall.

Install the package with:

pip install vicinity

Optinally, install any of the supported backends, or simply install all of them with:

pip install vicinity[all]

The following code snippet demonstrates how to use Vicinity for nearest neighbor search:

import numpy as np
from vicinity import Vicinity
from vicinity.datatypes import Backend, Metric

# Create some dummy data
items = ["triforce", "master sword", "hylian shield", "boomerang", "hookshot"]
vectors = np.random.rand(len(items), 128)

# Initialize the Vicinity instance (using the basic backend and cosine metric)
vicinity = Vicinity.from_vectors_and_items(vectors=vectors, items=items, backend_type=Backend.BASIC, metric=Metric.COSINE)

# Create a query vector
query_vector = np.random.rand(128)

# Query for nearest neighbors with a top-k search
results = vicinity.query([query_vector], k=3)

# Query for nearest neighbors with a threshold search
results = vicinity.query_threshold([query_vector], threshold=0.9)

Saving and loading a vector store:

vicinity.save('my_vector_store')
vicinity = Vicinity.load('my_vector_store')

Evaluating a backend:

# Use the first 1000 vectors as query vectors
query_vectors = vectors[:1000]

# Evaluate the Vicinity instance by measuring the queries per second and recall
qps, recall = vicinity.evaluate(
    full_vectors=vectors,
    query_vectors=query_vectors,
)

Vicinity provides the following features:

• Lightweight: Minimal dependencies and fast performance.
• Flexible Backend Support: Use different backends for vector storage and search.
• Serialization: Save and load vector stores for persistence.
• Evaluation: Easily evaluate the performance of different backends.
• Easy to Use: Simple and intuitive API.

The following backends are supported:

• BASIC: A simple (exact matching) flat index for vector storage and search.
• HNSW: Hierarchical Navigable Small World Graph (HNSW) for ANN search using hnswlib.
• USEARCH: ANN search using Usearch. This uses a highly optimized version of the HNSW algorithm.
• ANNOY: "Approximate Nearest Neighbors Oh Yeah" for approximate nearest neighbor search.
• PYNNDescent: ANN search using PyNNDescent.
• FAISS: All FAISS indexes are supported:
  • flat: Exact search.
  • ivf: Inverted file search.
  • hnsw: Hierarchical Navigable Small World Graph.
  • lsh: Locality Sensitive Hashing.
  • scalar: Scalar quantizer.
  • pq: Product Quantizer.
  • ivf_scalar: Inverted file search with scalar quantizer.
  • ivfpq: Inverted file search with product quantizer.
  • ivfpqr: Inverted file search with product quantizer and refinement.

NOTE: the ANN backends do not support dynamic deletion. To delete items, you need to recreate the index. Insertion is supported in the following backends: FAISS, HNSW, and Usearch. The BASIC backend supports both insertion and deletion.

The following installation options are available:

# Install the base package
pip install vicinity

# Install all backends
pip install vicinity[all]

# Install specific backends
pip install vicinity[annoy]
pip install vicinity[faiss]
pip install vicinity[hnsw]
pip install vicinity[pynndescent]
pip install vicinity[usearch]

MIT