Hacker News: Alternatives to cosine similarity

Source URL: https://tomhazledine.com/cosine-similarity-alternatives/
Source: Hacker News
Title: Alternatives to cosine similarity

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AI Summary and Description: Yes

Summary: The text discusses various methods for comparing vectors, particularly in the context of LLM embeddings, emphasizing the utility of cosine similarity over alternative distance functions like Euclidean and Manhattan distances. It underscores the significance of vector directionality in measuring textual similarity, offering insights that are particularly relevant for professionals working with AI, especially in the areas of embedding and retrieval in Natural Language Processing (NLP).

Detailed Description: The article provides an in-depth examination of different distance functions used to compare vectors, specifically focusing on LLM embeddings. The following points summarize the critical elements of the analysis:

* **Cosine Similarity**:
– Measures the cosine of the angle between two vectors, reflecting their directional similarity rather than magnitude.
– Used extensively in LLM applications, as embeddings represent the meaning of text.
– Fast computation due to OpenAI’s normalized embeddings, allowing simplification to the dot product.

* **Euclidean Distance**:
– Represents the straight-line distance between two points; calculated using the square root of the sum of squared differences.
– Offers equivalent rankings to cosine similarity when vectors are normalized, but includes more complex operations.

* **Manhattan Distance**:
– Measures the sum of absolute differences and is less influenced by outliers.
– Although it provides different numerical results, it generally maintains similar rankings to cosine and Euclidean distances.

* **Chebyshev Distance**:
– Focuses on the greatest absolute difference between components of the vectors, with limited application in LLM embeddings.

* **Performance Analysis**:
– The author tests execution times of various functions, finding cosine similarity (dot product) to be the fastest, followed closely by Euclidean distance.
– The study highlights that all functions perform comparably when normalized vectors are used, but cosine similarity remains the recommended method due to its focus on directionality and computational efficiency.

* **Conclusion**:
– For LLM embeddings, where directionality of vectors denotes meaning, cosine similarity is deemed the best choice, while also noting that Euclidean distance could serve as an efficient alternative due to the properties of normalized vectors.

These insights are crucial for security and compliance professionals operating in the realms of AI and information security, as the choice of distance function can impact the effectiveness of algorithms designed for data retrieval and processing. Understanding these principles can lead to more efficient and accurate systems playing a pivotal role in security measures that leverage AI technologies.